TY - JOUR TI - Two-Photon Absorption Properties of s-Triazine Derivatives With Near Octupolar Symmetry AU - Cui, Yue Zhi AU - Zhang, Yang AU - Zhou, Long Long AU - Yu, Fang T2 - AMR AB - Two new three-branched s-triazine derivatives with near-octupolar symmetry have been synthesized. In each of them, two branches have donor groups attaching to their ends, while the other one has none. Their photophysical characteristics, such as UV–vis spectra, fluorescence spectra and two-photon excited fluorescence spectra, are compared with their octuplar analogs in which all the three branches are ended by donor group. The little structural difference results in great decline of single-photon absorptivity and single-photon excited fluorescence, as well as the two-photon excitated fluorescence. DA - 2013/1// PY - 2013/1// DO - 10.4028/www.scientific.net/amr.652-654.542 VL - 652-654 SP - 542-545 ER - TY - JOUR TI - Evaporative cooling: effective latent heat of evaporation in relation to evaporation distance from the skin AU - Havenith, George AU - Bröde, Peter AU - den Hartog, Emiel den AU - Kuklane, Kalev AU - Holmer, Ingvar AU - Rossi, Rene M. AU - Richards, Mark AU - Farnworth, Brian AU - Wang, Xiaoxin T2 - Journal of Applied Physiology AB - Calculation of evaporative heat loss is essential to heat balance calculations. Despite recognition that the value for latent heat of evaporation, used in these calculations, may not always reflect the real cooling benefit to the body, only limited quantitative data on this is available, which has found little use in recent literature. In this experiment a thermal manikin, (MTNW, Seattle, WA) was used to determine the effective cooling power of moisture evaporation. The manikin measures both heat loss and mass loss independently, allowing a direct calculation of an effective latent heat of evaporation (λ eff ). The location of the evaporation was varied: from the skin or from the underwear or from the outerwear. Outerwear of different permeabilities was used, and different numbers of layers were used. Tests took place in 20°C, 0.5 m/s at different humidities and were performed both dry and with a wet layer, allowing the breakdown of heat loss in dry and evaporative components. For evaporation from the skin, λ eff is close to the theoretical value (2,430 J/g) but starts to drop when more clothing is worn, e.g., by 11% for underwear and permeable coverall. When evaporation is from the underwear, λ eff reduction is 28% wearing a permeable outer. When evaporation is from the outermost layer only, the reduction exceeds 62% (no base layer), increasing toward 80% with more layers between skin and wet outerwear. In semi- and impermeable outerwear, the added effect of condensation in the clothing opposes this effect. A general formula for the calculation of λ eff was developed. DA - 2013/3/15/ PY - 2013/3/15/ DO - 10.1152/japplphysiol.01271.2012 VL - 114 IS - 6 SP - 778–785 SN - 8750-7587 1522-1601 UR - http://dx.doi.org/10.1152/japplphysiol.01271.2012 KW - sweat KW - latent heat of evaporation KW - protective clothing KW - wicking KW - indirect calorimetry ER - TY - RPRT TI - Micro and nanofiber nonwoven spunbonded fabric AU - Pourdeyhimi, B. AU - Fedorova, N.V. AU - Sharp, S.R. DA - 2013/1/8/ PY - 2013/1/8/ M1 - US8349232B2 M3 - Patent SN - US8349232B2 ER - TY - RPRT TI - High strength, durable micro and nano-fiber fabrics produced by fibrillating bicomponent islands in the sea fibers AU - Pourdeyhimi, B. AU - Fedorova, N.V. AU - Sharp, S.R. DA - 2013/4/16/ PY - 2013/4/16/ M1 - US8420556B2 M3 - Patent SN - US8420556B2 ER - TY - CONF TI - Latest Developments in Nonwovens for Filtration, Keynote address AU - Pourdeyhimi, B. T2 - American Filtration Society C2 - 2013/// CY - Minnesota DA - 2013/// PY - 2013/// ER - TY - CONF TI - Nonwovens with Stretch and Recovery AU - Pourdeyhimi, B. T2 - TechTextil C2 - 2013/6// CY - Frankfurt, Germany DA - 2013/6// PY - 2013/6// ER - TY - CONF TI - Osteochondral Tissue Engineering Using Human Adipose Derived Stem Cells AU - Williams, J. AU - Mohiti-Asli, M. AU - Tuin, S.A. AU - Morgan, D. AU - Kannan, A. AU - Hluck, B. AU - Loboa, E.G. T2 - 59th Annual Orthopaedic Research Society Conference C2 - 2013/1// C3 - Proceeding of the 59th Annual Orthopaedic Research Society Conference CY - San Antonio, Texas DA - 2013/1// PY - 2013/1// ER - TY - CONF TI - Novel High Surface Area Poly(L-lactic Acid Nonwoven Scaffolds Exposed to Pulsatile Fluid Flow Increase RUNX2 Expression in Human Adipose Derived Stem Cells AU - Tuin, S.A. AU - Miller, S.M. AU - Ganesh, V. AU - Cunningham, D.J. AU - Pfeiler, W.T. AU - Bernacki, S.H. AU - Pourdeyhimi, B. AU - Loboa, E.G. T2 - Triennial International Engineered Fabrics Conference and Expo C2 - 2013/4// C3 - Proceedings of the triennial International Engineered Fabrics Conference and Expo CY - Miami Beach, Florida DA - 2013/4// PY - 2013/4// ER - TY - CONF TI - Winged Fiber Scaffolds Enhance hASC Proliferation, Osteogenesis, and Mechanosensitivity AU - Tuin, S.A. AU - Miller, S.M. AU - Cunningham, D.J. AU - Pfeiler, W.T. AU - Bernacki, S.H. AU - Pourdeyhimi, B. AU - Loboa, E.G. T2 - Annual Biomedical Engineering Society Conference C2 - 2013/9// C3 - Proceedings of the Annual Biomedical Engineering Society Conference CY - Seattle, WA DA - 2013/9// PY - 2013/9// ER - TY - CONF TI - 3-D Computational Modeling of Fluid Flow Over Winged Fibers: Winged Fibers Enhance Shear Stress and RUNX2 Expression in hASC AU - Tuin, S.A. AU - Cunningham, D.J. AU - Pfeiler, W.T. AU - Bernacki, S.H. AU - Pourdeyhimi, B. AU - Loboa, E.G. T2 - 15th Annual North Carolina Tissue Engineering and Regenerative Medicine Society Conference C2 - 2013/10// C3 - Proceedings of the 15th Annual North Carolina Tissue Engineering and Regenerative Medicine Society Conference CY - Winston-Salem, NC DA - 2013/10// PY - 2013/10// ER - TY - CONF TI - 3-D Computational Modeling of Fluid Flow Over Winged Fibers: Winged Fibers Enhance Shear Stress and RUNX2 Expression in hASC AU - Tuin, S.A. AU - Cunningham, D.J. AU - Pfeiler, W.T. AU - Bernacki, S.H. AU - Pourdeyhimi, B. AU - Loboa, E.G. T2 - Annual Joint Meeting of the Materials Research Society and the Materials Information Society C2 - 2013/11// C3 - Proceedings of the Annual Joint Meeting of the Materials Research Society and the Materials Information Society CY - Raleigh, NC DA - 2013/11// PY - 2013/11// ER - TY - CONF TI - Micro and Macro Modeling Filtration in Nonwovens AU - Pourdeyhimi, B. AU - Tafreshi, H. AU - Maze, B. T2 - Filtrex 2013 C2 - 2013/5// CY - Seoul, Korea DA - 2013/5// PY - 2013/5// ER - TY - RPRT TI - Biodegradable non-woven fabric having plant virus encapsulated actives for drug delivery AU - Pourdeyhimi, B. AU - Lommel, S.A. AU - Honarbakhsh, S. AU - Carbonell, R. AU - Guenther, R.H. DA - 2013/9/17/ PY - 2013/9/17/ M1 - 8535727 M3 - U.S. Patent SN - 8535727 ER - TY - RPRT TI - Lightweight High-Tensile, High-Tear Strength Bicomponent Nonwoven Fabrics AU - Pourdeyhimi, Behnam DA - 2013/11/13/ PY - 2013/11/13/ M1 - 5339896 M3 - Japan Patent SN - 5339896 ER - TY - RPRT TI - Durable Fabrics Produced by Fibrillating Multilobal Fibers AU - Pourdeyhimi, Behnam AU - Sharp, Stephen R. DA - 2013/4/3/ PY - 2013/4/3/ M1 - 2,165,010 M3 - Europe Patent SN - 2,165,010 ER - TY - RPRT TI - High Strength Durable Micro and Nano-Fiber Fabrics Produced by Fibrillating Islands in the Sea Fibers AU - Pourdeyhimi, Behnam DA - 2013/7/2/ PY - 2013/7/2/ M1 - 10-1280398 M3 - Korea Patent SN - 10-1280398 ER - TY - RPRT TI - High Strength Durable Micro and Nano-Fiber Fabrics Produced by Fibrillating Islands in the Sea Fibers AU - Pourdeyhimi, Behnam DA - 2013/8/21/ PY - 2013/8/21/ M1 - 5266050 M3 - Japan Patent SN - 5266050 ER - TY - RPRT TI - High Strength Durable Micro and Nano-Fiber Fabrics Produced by Fibrillating Islands in the Sea Fibers AU - Pourdeyhimi, Behnam AU - Sharp, Stephen R. AU - Fedorova, Nataliya DA - 2013/5/2/ PY - 2013/5/2/ M1 - EP1907201 M3 - Germany Patent SN - EP1907201 ER - TY - RPRT TI - Composite Filter Media with High Surface Area Fibers AU - Pourdeyhimi, Behnam AU - Chappas, Walter DA - 2013/4/2/ PY - 2013/4/2/ M1 - 8,410,006 M3 - U.S. Patent SN - 8,410,006 ER - TY - JOUR TI - A Pd-free activation method for electroless nickel deposition on copper AU - Tian, Dong AU - Li, De Y. AU - Wang, Fang F. AU - Xiao, Ning AU - Liu, Rui Q. AU - Li, Ning AU - Li, Qing AU - Gao, Wei AU - Wu, Gang T2 - Surface and Coatings Technology AB - In this work, a Pd-free activation method for electroless nickel deposition on copper via an immersion nickel technique was developed. In the very solution we studied, high concentration of thiourea resulted in a negative shift of the steady potential of copper, making it possible to realize immersion nickel. The obtained immersion nickel layers were characterized by scanning electron microscopy, energy dispersive X-ray spectrometry and X-ray photoelectron spectroscopy, demonstrating a co-deposition of sulfur in the nickel layer. Importantly, the post-treatment in 1.0 M NaH2PO2 + 1.0 M NaOH solution was able to eliminate the adsorbed thiourea and stimulate the catalytic activity of the immersion nickel layer for electroless nickel deposition. A combination of open circuit potential measurements and morphology studies indicated that an incubation step was required during the electroless nickel deposition on the immersion nickel layers after post-treatment. Although the catalytic activity of this Ni-activation method was slightly lower as compared to the conventional Pd-activation, both obtained electroless Ni–P layers exhibited similar morphology, chemical composition, corrosion resistance, and adhesion strength. Thus, this work demonstrated that the newly developed Ni-activation method was cost-effective and could be a promising replacement to expensive Pd-activation method currently used in printed circuit board industries. DA - 2013/8// PY - 2013/8// DO - 10.1016/J.SURFCOAT.2013.03.048 VL - 228 SP - 27-33 J2 - Surface and Coatings Technology LA - en OP - SN - 0257-8972 UR - http://dx.doi.org/10.1016/J.SURFCOAT.2013.03.048 DB - Crossref KW - Pd-free activation KW - Immersion nickel layers KW - Copper KW - Thiourea KW - Electroless nickel deposition ER - TY - JOUR TI - Effect of high-temperature thermal treatment on the structure and adsorption properties of reduced graphene oxide AU - Song, Li AU - Khoerunnisa, Fitri AU - Gao, Wei AU - Dou, Weihong AU - Hayashi, Takuya AU - Kaneko, Katsumi AU - Endo, Morinobu AU - Ajayan, Pulickel M. T2 - Carbon AB - We present the study on the structure and adsorption properties of reduced graphene oxide subjected to thermal treatment in temperature range of 1100–2000 °C under flowing argon. The morphology and composition analyses reveal that the defective carbon materials remaining after volatilization of oxygen and hydrogen rearrange into highly ordered hexagonal carbon layers during thermal treatment at 2000 °C. The surface area of the resulting carbon layers increases to a value more than fourfold over that of the starting precursor materials. These results offer useful insights to understand the thermal behavior of the carbonaceous decomposition materials. DA - 2013/2// PY - 2013/2// DO - 10.1016/j.carbon.2012.09.060 VL - 52 SP - 608-612 J2 - Carbon LA - en OP - SN - 0008-6223 UR - http://dx.doi.org/10.1016/j.carbon.2012.09.060 DB - Crossref ER - TY - JOUR TI - Displacement between Orders of Magnitude Method for SI Unit Conversion AU - Ford, Ericka N. J. AU - Gilbert, Yvette V. T2 - Journal of Chemical Education AB - The displacement between orders of magnitude (DBOM) method was introduced to help high school chemistry and physical science students perform conversions between units of the international system (SI). Students were taught how to numerically solve for the total number of placements between a set of units. The integer value, representing the DBOM, determines the multiples of 10 by which the coefficient should be reduced or increased. Further, the DBOM method gives a scaling factor between dissimilar SI units. This communication defines and gives instruction on how to teach the DBOM method within the classroom. DA - 2013/// PY - 2013/// DO - 10.1021/ed300006e VL - 90 IS - 1 SP - 134–136 SN - 0021-9584 1938-1328 UR - http://dx.doi.org/10.1021/ed300006e KW - High School/Introductory Chemistry KW - Misconceptions/Discrepant Events KW - Demonstrations KW - Mathematics/Symbolic Mathematics KW - Nomenclature/Units/Symbols ER - TY - JOUR TI - Interconnected, microporous hollow fibers for tissue engineering: Commercially relevant, industry standard scale-up manufacturing AU - Tuin, Stephen A. AU - Pourdeyhimi, Behnam AU - Loboa, Elizabeth G. T2 - Journal of Biomedical Materials Research Part A AB - Significant progress has been achieved in the field of tissue engineering to create functional tissue using biomimetic three-dimensional scaffolds that support cell growth, proliferation, and extracellular matrix production. However, many of these constructs are severely limited by poor nutrient diffusion throughout the tissue-engineered construct, resulting in cell death and tissue necrosis at the core. Nutrient transport can be improved by creation and use of scaffolds with hollow and microporous fibers, significantly improving permeability and nutrient diffusion. The purpose of this review is to highlight current technological advances in the fabrication of hollow fibers with interconnected pores throughout the fiber walls, with specific emphasis on developing hollow porous nonwoven fabrics for use as tissue engineering constructs via industry standard processing technologies: Spunbond processing and polymer melt extrusion. We outline current methodologies to create hollow and microporous scaffolds with the aim of translating that knowledge to the production of such fibers into nonwoven tissue engineering scaffolds via spunbond technology, a commercially relevant and viable melt extrusion manufacturing approach that allows for facile scale-up. DA - 2013/10/28/ PY - 2013/10/28/ DO - 10.1002/JBMA.35002 VL - 102 IS - 9 SP - 3311-3323 J2 - J. Biomed. Mater. Res. LA - en OP - SN - 1549-3296 UR - http://dx.doi.org/10.1002/jbm.a.35002 DB - Crossref ER - TY - JOUR TI - Forced convection mass deposition and heat transfer onto a cylinder sheathed by protective garments AU - Ambesi, Davide AU - Kleijn, Chris R. AU - den Hartog, Emiel A. AU - Bouma, Richard H. B. AU - Brasser, Paul T2 - AIChE Journal AB - In chemical, biological, radiological, and nuclear protective clothing, a layer of activated carbon material in between two textile layers provides protection against hazardous gases. A cylinder in cross flow, sheathed by such material, is generally used to experimentally test the garment properties. This is, however, complicated and predictive models are needed. We present a computational fluid dynamics model for the initial phase in which the carbon filter material is not yet saturated. The textiles are modeled as chemically inactive porous layers, the carbon filter particles have been resolved explicitly. The model has been validated against experimental data. We demonstrate that (1) computational fluid dynamics simulations can be used for the efficient design and optimization of protective garments, and (2) the addition of a highly porous active carbon layer highly increases the chemical protection capabilities, while having relatively little negative impact on the thermal comfort of protective garments. © 2013 American Institute of Chemical Engineers AIChE J , 60: 353–361, 2014 DA - 2013/10/21/ PY - 2013/10/21/ DO - 10.1002/AIC.14246 VL - 60 IS - 1 SP - 353-361 J2 - AIChE J. LA - en OP - SN - 0001-1541 UR - http://dx.doi.org/10.1002/AIC.14246 DB - Crossref KW - chemical KW - biological KW - radiological KW - and nuclear protective garments KW - cylinder KW - active carbon filter KW - heat transfer KW - mass transfer KW - computational fluid dynamics KW - turbulence KW - time-dependent Reynolds-averaged Navier-Stokes ER - TY - JOUR TI - Predicting the Chemical Protection Factor of CBRN Protective Garments AU - Ambesi, Davide AU - Bouma, Richard AU - den Hartog, Emiel AU - Kleijn, Chris R. T2 - Journal of Occupational and Environmental Hygiene AB - The protection factor and pressure drop coefficient of single layers of active carbon particles in chemical, biological, radiological, and nuclear (CBRN) protective garments have been computed from computational fluid dynamics simulations of airflow and mass transport. Based on the results from the simulations, a closed-form analytical model has been proposed for the protection factor and the pressure drop coefficient as a function of layer porosity, particle diameter, and cross airflow velocity. This model has been validated against experimental data in literature. It can be used to find an optimal compromise between high protection factor and low pressure drop coefficient. Maximum protection factors are achieved when small carbon particles are employed in a layer with high packing density, at the expense of a high pressure drop coefficient. For a given required protection factor, the lowest pressure drop coefficient is found for layers combining a high porosity and small particle diameter. DA - 2013/5// PY - 2013/5// DO - 10.1080/15459624.2013.769842 VL - 10 IS - 5 SP - 270-276 J2 - Journal of Occupational and Environmental Hygiene LA - en OP - SN - 1545-9624 1545-9632 UR - http://dx.doi.org/10.1080/15459624.2013.769842 DB - Crossref KW - air resistance KW - CBRN protective garments KW - protection factor ER - TY - JOUR TI - Cellulose and Soy Proteins Based Membrane Networks AU - Zhu, Yidan AU - Douglass, Eugene AU - Theyson, Tom AU - Hogan, Robina AU - Kotek, Richard T2 - Macromolecular Symposia AB - Summary Using the novel ethylenediamine/potassium thiocyanate (ED/KSCN) solvent system developed in our labs, a simpler, environmentally friendlier method was developed to produce membranes using cellulose, proteins, and other polymers. In contrast to current industrial methods that use processes that are relatively expensive with toxic or dangerous solvents, the new system eliminated majority of those concerns. In this study, soy protein concentrate and cellulose was used to develop a nonporous composite membrane with good physical properties. Glutaraldehyde was applied as the crosslinking agent to stabilize the molecular network structure of the blended membranes. Results showed that nonporous membranes were produced that were strong, flexible, and the exposure to the crosslinking agent shown structural and thermal improvement of the network membranes. This resulting blend of biopolymer membranes with improved physical abilities can be useful for food packaging, filtration systems, or even medical applications. DA - 2013/7// PY - 2013/7// DO - 10.1002/MASY.201300032 VL - 329 IS - 1 SP - 70-86 J2 - Macromol. Symp. LA - en OP - SN - 1022-1360 UR - http://dx.doi.org/10.1002/MASY.201300032 DB - Crossref KW - cellulose KW - crosslinking KW - glutaraldehyde KW - network KW - soy proteins ER - TY - JOUR TI - Hybrid mixed media nonwovens composed of macrofibers and microfibers. Part I: three-layer segmented pie configuration AU - Hollowell, Kendall B. AU - Anantharamaiah, Nagendra AU - Pourdeyhimi, Behnam T2 - Journal of the Textile Institute AB - Nonwoven fabrics, composed of microdenier fibers, can be easily created by using splittable bicomponents such as segmented pie. Hydroentangling has been shown as a very effective method for mechanically splitting these fibers. Such structures are known to form a densely packed nonwoven fabric with concomitant consequences in low porosity and tear strength. It is not, therefore, uncommon to insert a reinforcing scrim as a “rip-stop” mechanism in the middle of such structures to improve their properties, especially tear resistance. Instead, we propose a hybrid structure where the middle portion consists of solid homocomponent fibers, made from the same polymer as one of the components used in the bicomponent fibers, produced simultaneously during web formation, without causing noticeable changes in the fabrics’ overall texture. We report on the production and properties of fabrics composed entirely of bicomponent segmented pie fibers as well as our hybrid fabrics arranged in a three-layer configuration. DA - 2013/9// PY - 2013/9// DO - 10.1080/00405000.2013.767430 VL - 104 IS - 9 SP - 972-979 J2 - Journal of The Textile Institute LA - en OP - SN - 0040-5000 1754-2340 UR - http://dx.doi.org/10.1080/00405000.2013.767430 DB - Crossref ER - TY - JOUR TI - A simple simulation method for designing fibrous insulation materials AU - Arambakam, R. AU - Vahedi Tafreshi, H. AU - Pourdeyhimi, B. T2 - Materials & Design AB - Conductive heat in a fibrous material travels through both the air (interstitial fluid) and the fibers (solid phase). The numerical simulations reported in this paper are devised to study the effective thermal conductivity of fibrous media with different microstructural parameters. Simulations were conducted in 3-D fibrous geometries resembling the microstructure of a fibrous material. Assuming that the heat transfer through the interstitial fluid is independent of the geometrical parameters of the solid phase (for when the porosity is held constant), the energy equation was solved only for the solid structures, and the resulting values were used to predict the effective thermal conductivity of the whole media. This treatment allows us to drastically reduce the computational cost of such simulations. The results indicate that heat conduction through the solid fibrous structure increases by increasing the material’s solid volume fraction, fiber diameter, and fibers’ through-plane orientations. The in-plane orientation of the fibers, on the other hand, did not show any significant influence on the material’s conductivity. It was also shown that the microstructural parameters of fibrous insulations have negligible influence on the material’s performance if the conductivity of the solid phase is close to that of the interstitial fluid. DA - 2013/2// PY - 2013/2// DO - 10.1016/j.matdes.2012.07.058 VL - 44 SP - 99-106 J2 - Materials & Design LA - en OP - SN - 0261-3069 UR - http://dx.doi.org/10.1016/j.matdes.2012.07.058 DB - Crossref KW - Conductive heat transfer KW - Fibrous materials KW - Insulation materials KW - Numerical simulation ER - TY - JOUR TI - 3-D microscale simulation of dust-loading in thin flat-sheet filters: A comparison with 1-D macroscale simulations AU - Saleh, A.M. AU - Hosseini, S.A. AU - Vahedi Tafreshi, H. AU - Pourdeyhimi, B. T2 - Chemical Engineering Science AB - In this work, a microscale approach is undertaken to simulate the instantaneous pressure drop and collection efficiency of fibrous media exposed to particle loading, i.e., filter aging. The air flow field through 3-D disordered geometries representing the internal microstructure of a fibrous filter is obtained by numerically solving Stokes' equations. A Lagrangian approach is used to track the trajectory of particles through our virtual filter media and determine the filter's collection efficiency under different dust-load conditions. The calculations were conducted using the ANSYS CFD code enhanced with a series of in-house C++ subroutines. To better illustrate the value of such CPU-intensive 3-D microscale modeling, we compared the results of our simulations with those obtained from a 1-D macroscale model developed based on some of the pioneering studies reported in the literature. It was found that while the 1-D macroscale models can provide fast predictions for the pressure drop and collection efficiency of a given filter, they require a series of empirical correction factors or case-specific assumptions that limit their usage for design and development of new filter media. The 3-D microscale simulation methods, in contrast, are self-sufficient as they are developed based on first principles. With the current rate of progress in developing high-speed computers, it is expected that 3-D microscale simulations will be the preferred method of filter design in the near future. DA - 2013/8// PY - 2013/8// DO - 10.1016/J.CES.2013.06.007 VL - 99 SP - 284-291 J2 - Chemical Engineering Science LA - en OP - SN - 0009-2509 UR - http://dx.doi.org/10.1016/J.CES.2013.06.007 DB - Crossref KW - Aerosol KW - CFD KW - Filtration KW - Separations KW - Porous media KW - Fibrous media ER - TY - JOUR TI - Impacts of high-speed waterjets on web structures AU - Suragani Venu, Lalith B. AU - Shim, Eunkyoung AU - Anantharamaiah, Nagendra AU - Pourdeyhimi, Behnam T2 - The Journal of The Textile Institute AB - AbstractHydroentangling, where a fabric is formed by striking of fine, closely spaced, high speed waterjets, is one of the fastest growing bonding methods in the nonwoven industry. Softness, drape, conformability, and relatively high strength are the major characteristics that make this bonding technology unique. Despite the method appeal, few understand the impact of waterjet on fabric structures. The primary function of waterjet is to produce fiber entangling, which induces web integrity. In this paper, we have analyzed the interaction of waterjets on web structures to provide a better understanding of the hydroentangling mechanism. We have successfully visualized and analyzed structures of entangled regions through 2D and 3D imaging techniques. The influence of water-jet pressure, jet diameter, and number of jets on hydroentangled web structures is reported.Keywords: nonwovenshydroentanglingthree-dimensional structuresentanglementfiber orientation AcknowledgementThe current work was supported by the Nonwovens Cooperative Research Center and its support is gratefully acknowledged. DA - 2013/9/9/ PY - 2013/9/9/ DO - 10.1080/00405000.2013.819613 VL - 105 IS - 4 SP - 430-443 J2 - The Journal of The Textile Institute LA - en OP - SN - 0040-5000 1754-2340 UR - http://dx.doi.org/10.1080/00405000.2013.819613 DB - Crossref ER - TY - JOUR TI - Basis weight uniformity analysis in nonwovens AU - Amirnasr, Elham AU - Shim, Eunkyoung AU - Yeom, Bong-Yeol AU - Pourdeyhimi, Behnam T2 - The Journal of The Textile Institute AB - It is widely recognized that nonwoven basis weight uniformity affects various properties of nonwovens, including appearance, physical properties, or mechanical properties. However, it is one of the nonwoven characteristics that is most difficult to characterize. This paper reports on the methodology based on the well-known quadrant method that objectively quantifies uniformity of nonwoven fabrics. DA - 2013/9/5/ PY - 2013/9/5/ DO - 10.1080/00405000.2013.820017 VL - 105 IS - 4 SP - 444-453 ER - TY - JOUR TI - Aerosol filtration properties of nucleating agent containing electret filters AU - Kilic, Ali AU - Shim, Eunkyoung AU - Pourdeyhimi, Behnam AU - Yeom, Bong-Yeol T2 - Polym Eng Sci AB - This study reports on the effects of nucleating agents on morphology, charging, and electrostatic filtration performance of polypropylene meltblown webs. Two commercial nucleating agents, DMDBS (3:2, 4‐bis(3,4‐dimethyldibenzylidene) sorbitol) and NA11 (sodium 2,2′‐methylene‐bis(4,6‐di‐tertbutylphenyl)‐phosphate) were compared. It is hypothesized that faster solidification brought about by the addition of the nucleating agents may be responsible for the slight increase in fiber diameter and concomitant reduction in web solidity. Samples were charged at room temperature as well as at elevated temperatures. Upon thermal charging, significant enhancement in the electrostatic potential and filtration performance of the webs was observed. Particularly, the stability of electrostatic filtration performance was found to be promising with the addition of these polarizable additives. Dielectric spectroscopy tests confirmed an increase in capacitance for samples containing nucleating agents. POLYM. ENG. SCI., 54:1533–1539, 2014. © 2013 Society of Plastics Engineers DA - 2013/7// PY - 2013/7// DO - 10.1002/pen.23693 VL - 54 IS - 7 SP - 1533-1539 ER - TY - JOUR TI - Hyaluronan-Based Three-Dimensional Microenvironment Potently Induces Cardiovascular Progenitor Cell Populations T2 - ISRN Tissue Engineering AB - The relationship between stem cell niches in vivo and their surrounding microenvironment is still relatively unknown. Recent advances have indicated that extrinsic factors within the cardiovascular progenitor cell niche influence maintenance of a multipotent state as well as drive cell-fate decisions. We have previously shown the direct effects of extracellular matrix (ECM) proteins and have now investigated the effects of dimension on the induction of a cardiovascular progenitor cell (CPC) population. We have shown here that the three-dimensionality of a hyaluronan-based hydrogel greatly induces a CPC population, as marked by Flk-1. We have compared the effects of a 3D microenvironment to those of conventional 2D cell culture practices and have found that the 3D microenvironment potently induces a progenitor cell state. DA - 2013/// PY - 2013/// DO - 10.1155/2013/752620 UR - http://dx.doi.org/10.1155/2013/752620 ER - TY - JOUR TI - simple method to encapsulate SnSb nanoparticles into hollow carbon nanofibers with superior lithium-ion storage capability AU - Xue, L. G. AU - Xia, X. AU - Tucker, T. AU - Fu, K. AU - Zhang, S. AU - Li, S. L. AU - Zhang, X. W. T2 - Journal of Materials Chemistry A DA - 2013/// PY - 2013/// VL - 1 ER - TY - JOUR TI - Synthesis and characterization of xLi(2)MnO(3) center dot (1-x)LiMn1/3Ni1/3Co1/3O2 composite cathode materials for rechargeable lithium-ion batteries AU - Toprakci, O. AU - Toprakci, H. A. K. AU - Li, Y. AU - Ji, L. W. AU - Xue, L. G. AU - Lee, H. AU - Zhang, S. AU - Zhang, X. W. T2 - Journal of Power Sources DA - 2013/// PY - 2013/// VL - 241 ER - TY - JOUR TI - Si/C composite nanofibers with stable electric conductive network for use as durable lithium-ion battery anode AU - Xue, L. G. AU - Fu, K. AU - Li, Y. AU - Xu, G. J. AU - Lu, Y. AU - Zhang, S. AU - Toprakci, O. AU - Zhang, X. W. T2 - Nano Energy DA - 2013/// PY - 2013/// VL - 2 ER - TY - JOUR TI - Analysis of carbohydrates by atmospheric pressure chloride anion attachment tandem mass spectrometry AU - Vinueza, Nelson R. AU - Gallardo, Vanessa A. AU - Klimek, John F. AU - Carpita, Nicholas C. AU - Kenttämaa, Hilkka I. T2 - Fuel AB - The ability to characterize oligosaccharides directly in complex mixtures would greatly benefit many research efforts focused on the development of biofuels from lignocellulosic biomass. We report here on the utility of chloride anion attachment in atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) tandem mass spectrometry for MW determination and structural elucidation of several mono-, di- and oligosaccharides directly without sample pretreatment or derivatization. Chloride anion forms stable adducts with these sugars upon ESI or APCI, which can be readily identified due to the chlorine isotope pattern. Fragment anions or other product anions are usually not observed, which is beneficial for mixture analysis. Upon collisional activation in MS2 experiments, these adducts readily lose HCl, which helps verify the molecular weight of each analyte. Isolating the resulting anion and subjecting it to further collision-activated dissociation experiments (MSn; n = 3–4) until no ion signal remains yields useful structural information. Examination of equimolar mixtures of mono-, di- and oligosaccharides and mixtures of enzymatically digested biomass demonstrates the ability of this methodology to ionize all the components of the mixtures without bias and with nearly equal efficiency. DA - 2013/3// PY - 2013/3// DO - 10.1016/j.fuel.2012.08.012 VL - 105 SP - 235-246 J2 - Fuel LA - en OP - SN - 0016-2361 UR - http://dx.doi.org/10.1016/j.fuel.2012.08.012 DB - Crossref KW - Oligosaccharides KW - Atmospheric pressure ionization KW - Atmospheric pressure chemical ionization KW - Chloride attachment KW - Tandem mass spectrometry KW - Bio-oil ER - TY - JOUR TI - Analysis of xyloglucans by ambient chloride attachment ionization tandem mass spectrometry AU - Vinueza, Nelson R. AU - Gallardo, Vanessa A. AU - Klimek, John F. AU - Carpita, Nicholas C. AU - Kenttämaa, Hilkka I. T2 - Carbohydrate Polymers AB - Xyloglucan oligomers obtained upon enzyme digestion from Hymenaea courbaril, Arabidopsis Columbia-0 and mur3 were ionized and analyzed by using chloride anion attachment electrospray ionization (ESI) and tandem mass spectrometry. MW determination and structural elucidation of several xyloglucan oligomers was performed directly from the mixture solutions without sample pretreatment or derivatization. Sodium cation attachment was used to determine the number of xyloglucans present in the mixtures and their MWs. However, tandem mass spectrometry results showed that structure elucidation based on the sodium adducts is ambiguous. Chloride anion also forms stable adducts with these xyloglucans upon ESI. These adducts can be readily identified due to the chlorine isotope pattern. The mass spectral profile of xyloglucans obtained for the mixtures matches the HPAEC results, thus validating this methodology for the determination of the xyloglucan composition and the MW of each xyloglucan. Upon collisional activation in MS2 experiments, the chloride anion adducts readily lose HCl, which helps verify the molecular weight of each xyloglucan. Isolating the resulting anion (deprotonated oligomer) and subjecting it to further collision-activated dissociation experiments (MSn; n = 3–4) yields useful structural information that allows the differentiation between isomeric anions and hence determination of the sequence of the xyloglucan oligomers. The deprotonated oligomers fragment by a stepwise loss of sugar units from the reducing end. DA - 2013/10// PY - 2013/10// DO - 10.1016/j.carbpol.2013.06.070 VL - 98 IS - 1 SP - 1203-1213 J2 - Carbohydrate Polymers LA - en OP - SN - 0144-8617 UR - http://dx.doi.org/10.1016/j.carbpol.2013.06.070 DB - Crossref KW - Xyloglucans KW - Electrospray ionization KW - Chloride attachment KW - Tandem mass spectrometry KW - Hymenaea courbaril, Arabidopsis thaliana mur3 KW - Sequencing ER - TY - JOUR TI - On-Line Mass Spectrometric Methods for the Determination of the Primary Products of Fast Pyrolysis of Carbohydrates and for Their Gas-Phase Manipulation AU - Hurt, Matthew R. AU - Degenstein, John C. AU - Gawecki, Piotr AU - Borton II, David J. AU - Vinueza, Nelson R. AU - Yang, Linan AU - Agrawal, Rakesh AU - Delgass, W. Nicholas AU - Ribeiro, Fabio H. AU - Kenttämaa, Hilkka I. T2 - Analytical Chemistry AB - Mass spectrometric methodology was developed for the determination and manipulation of the primary products of fast pyrolysis of carbohydrates. To determine the true primary pyrolysis products, a very fast heating pyroprobe was coupled to a linear quadrupole ion trap mass spectrometer through a custom-built adaptor. A home-built flow tube that simulates pyrolysis reactor conditions was used to examine the secondary reactions of the primary products. Depending on the experiment, the pyrolysis products were either evaporated and quenched or allowed to react for a period of time. The quenched products were ionized in an atmospheric pressure chemical ionization (APCI) source infused with one of two ionization reagents, chloroform or ammonium hydroxide, to aid in ionization. During APCI in negative ion mode, chloroform produces chloride anions that are known to readily add to carbohydrates with little bias and little to no fragmentation. On the other hand, in positive ion mode APCI, ammonium hydroxide forms ammonium adducts with carbohydrates with little to no fragmentation. The latter method ionizes compounds that are not readily ionized upon negative ion mode APCI, such as furan derivatives. Six model compounds were studied to verify the ability of the ionization methods to ionize known pyrolysis products: glycolaldehyde, hydroxyacetone, furfural, 5-hydroxymethylfurfural, levoglucosan, and cellobiosan. The method was then used to examine fast pyrolysis of cellobiose. The primary fast pyrolysis products were determined to consist of only a handful of compounds that quickly polymerize to form anhydro-oligosaccharides when allowed to react at high temperatures for an extended period of time. DA - 2013/11/4/ PY - 2013/11/4/ DO - 10.1021/ac402380h VL - 85 IS - 22 SP - 10927-10934 J2 - Anal. Chem. LA - en OP - SN - 0003-2700 1520-6882 UR - http://dx.doi.org/10.1021/ac402380h DB - Crossref ER - TY - JOUR TI - Does the 2,6-didehydropyridinium cation exist? AU - Jankiewicz, Bartłomiej J. AU - Vinueza, Nelson R. AU - Kirkpatrick, Lindsey M. AU - Gallardo, Vanessa A. AU - Li, Guannan AU - Nash, John J. AU - Kenttämaa, Hilkka I. T2 - Journal of Physical Organic Chemistry AB - Reactive intermediates are key species involved in many chemical and biochemical processes. For example, carbon-centered aromatic σ,σ-biradicals formed in biological systems from naturally occurring enediyne antitumor antibiotics are responsible for the irreversible cleavage of double-stranded DNA caused by these prodrugs. However, because of their high reactivity, it is very difficult or impossible to isolate and investigate these biradicals. The aromatic σ,σ-biradical, 2,6-didehydropyridine, has been speculated for many years to be formed in certain organic reactions; however, no definitive proof of its generation has been obtained. We report here the successful generation of protonated 2,6-didehydropyridine and the examination of its chemical properties in the gas phase by using a Fourier transform ion cyclotron resonance mass spectrometer. The results suggest that a mixture of singlet (ground) state and triplet (excited) state 2,6-didehydropyridinium cations was generated. The two different states show qualitatively different reactivity, with the triplet state showing greater Brønsted acidity than that of the singlet state. The triplet state also shows much greater radical reactivity than that of the singlet state, as expected because of the coupling of the nonbonding electrons in the singlet state. DA - 2013/6/5/ PY - 2013/6/5/ DO - 10.1002/poc.3120 VL - 26 IS - 9 SP - 707-714 J2 - J. Phys. Org. Chem. LA - en OP - SN - 0894-3230 UR - http://dx.doi.org/10.1002/poc.3120 DB - Crossref KW - Didehydrobenzene KW - FT-ICR KW - biradicals KW - ion-molecule reactions KW - reactive intermediates ER - TY - JOUR TI - Experimental and Computational Studies on the Formation of Threepara-Benzyne Analogues in the Gas Phase AU - Kirkpatrick, Lindsey M. AU - Vinueza, Nelson R. AU - Jankiewicz, Bartłomiej J. AU - Gallardo, Vanessa A. AU - Archibold, Enada F. AU - Nash, John J. AU - Kenttämaa, Hilkka I. T2 - Chemistry - A European Journal AB - Abstract Experimental and computational studies on the formation of three gaseous, positively‐charged para ‐benzyne analogues in a Fourier transform ion cyclotron resonance (FT‐ICR) mass spectrometer are reported. The structures of the cations were examined by isolating them and allowing them to react with various neutral reagents whose reactions with aromatic carbon‐centered σ‐type mono‐ and biradicals are well understood. Cleavage of two iodine–carbon bonds in N ‐deuterated 1,4‐diiodoisoquinolinium cation by collision‐activated dissociation (CAD) produced a long‐lived cation that showed nonradical reactivity, which was unexpected for a para ‐benzyne. However, the reactivity closely resembles that of an isomeric enediyne, N ‐deuterated 2‐ethynylbenzonitrilium cation. A theoretical study on possible rearrangement reactions occurring during CAD revealed that the cation formed upon the first iodine atom loss undergoes ring‐opening before the second iodine atom loss to form an enediyne instead of a para ‐benzyne. Similar results were obtained for the 5,8‐didehydroisoquinolinium cation and the 2,5‐didehydropyridinium cation. The findings for the 5,8‐didehydroisoquinolinium cation are in contradiction with an earlier report on this cation. The cation described in the literature was regenerated by using the literature method and demonstrated to be the isomeric 5,7‐didehydro‐isoquinolinium cation and not the expected 5,8‐isomer. DA - 2013/5/22/ PY - 2013/5/22/ DO - 10.1002/chem.201203264 VL - 19 IS - 27 SP - 9022-9033 J2 - Chem. Eur. J. LA - en OP - SN - 0947-6539 UR - http://dx.doi.org/10.1002/chem.201203264 DB - Crossref KW - biradicals KW - distonic ions KW - ion-molecule reactions KW - para-benzyne KW - mass spectrometry KW - ring-opening ER - TY - CHAP TI - Hemostatic wound dressings AU - Gajjar, C.R. AU - McCord, M.G. AU - King, M.W. T2 - Biotextiles as Medical Implants AB - Hemorrhage is uncontrolled bleeding from a wound. Various studies indicate that hemorrhage is a major cause of ‘potentially preventable’ deaths in combat as well as civilian trauma. New methods and products for hemorrhage control are therefore a research priority to avoid potentially survivable deaths. A better understanding of the correlation between surface properties and their hemostatic potential (i.e. ability to form a blood clot) would result in an effective hemostatic wound dressing. This chapter describes the blood clotting mechanism and the effect of foreign surfaces on the coagulation cascade. Finally, a review of the various approaches to develop an ideal hemostatic material is presented. PY - 2013/// DO - 10.1533/9780857095602.2.563 SP - 563-589 OP - PB - Elsevier SN - 9781845694395 UR - http://dx.doi.org/10.1533/9780857095602.2.563 DB - Crossref KW - blood clot KW - thrombus KW - coagulation cascade KW - hemorrhage KW - hemostatic textiles KW - wound dressing ER - TY - CONF TI - Thermoplastic elastomer systems for stimulated shape change: From electrical actuation to thermal recovery AU - Spontak, R.J. AU - Tallury, S.S. AU - Ghosh, T.K. AU - Pasquinelli, M.A. AU - Pourdeyhimi, B. C2 - 2013/// C3 - International Symposium on Fibers Interfacing the World DA - 2013/// UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84969786883&partnerID=MN8TOARS ER - TY - CONF TI - Combined experimental and simulation approach to tailor the microstructures of polymer materials through inclusion complex formation and subsequent release AU - Gurarslan, Alper AU - Pasquinelli, Melissa A AU - Tonelli, Alan E T2 - AMER CHEMICAL SOC 1155 16TH ST, NW, WASHINGTON, DC 20036 USA C2 - 2013/// C3 - ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY DA - 2013/// VL - 245 ER - TY - JOUR TI - Novel atmospheric plasma enhanced chitosan nanofiber/gauze composite wound dressings AU - Nawalakhe, R. AU - Shi, Q. AU - Vitchuli, N. AU - Noar, J. AU - Caldwell, J. M. AU - Breidt, F. AU - Bourham, M. A. AU - Zhang, X. AU - McCord, M. G. T2 - Journal of Applied Polymer Science AB - Abstract Electrospun chitosan nanofibers were deposited onto atmospheric plasma treated cotton gauze to create a novel composite bandage with higher adhesion, better handling properties, enhanced bioactivity, and moisture management. Plasma treatment of the gauze substrate was performed to improve the durability of the nanofiber/gauze interface. The chitosan nanofibers were electrospun at 3–7% concentration in trifluoroacetic acid. The composite bandages were analyzed using peel, gelbo flex, antimicrobial assay, moisture vapor transmission rate, X‐ray photoelectron spectroscopy (XPS), absorbency, and air permeability tests. The peel test showed that plasma treatment of the substrate increased the adhesion between nanofiber layers and gauze substrate by up to four times. Atmospheric plasma pretreatment of the gauze fabric prior to electrospinning significantly reduced degradation of the nanofiber layer due to repetitive flexing. The chitosan nanofiber layer contributes significantly to the antimicrobial properties of the bandage. Air permeability and moisture vapor transport were reduced due to the presence of a nanofiber layer upon the substrate. XPS of the plasma treated cotton substrate showed formation of active sites on the surface, decrease in carbon content, and increase in oxygen content as compared to the untreated gauze. Deposition of chitosan nanofibers also increased the absorbency of gauze substrate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 DA - 2013/// PY - 2013/// DO - https://doi.org/10.1002/app.38804 VL - 129 ER - TY - JOUR TI - Multifunctional and durable nanofiber-fabric-layered composite for protective application AU - Shi, Q. AU - Vitchuli, N. AU - Nowak, J. AU - Jiang, S. AU - Caldwell, J. M. AU - Breidt, F. AU - Bourham, M. AU - Zhang, X. W. AU - McCord, M. T2 - Journal of Applied Polymer Science AB - A multifunctional and durable nanofiber-fabric-layered composite (NFLC) material was prepared by depositing electrospun Ag/PAN hybrid nanofibers onto a Nylon/cotton 50: 50 fabric substrate. The NFLCs showed excellent aerosol barrier efficiency and good air/moisture permeability. In addition, they showed excellent antibacterial efficiency by completely inhibiting the growth of both Gram-negative E. coli and Gram-positive S. aureus. The interfacial adhesion between the nanofiber layer and fabric substrate was significantly improved by atmospheric plasma pretreatment of the substrate. The resultant NFLCs showed excellent resistance to peeling, twisting, and flexing forces. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 DA - 2013/// PY - 2013/// DO - https://doi.org/10.1002/app.38465 VL - 128 ER - TY - JOUR TI - Co3O4/Carbon Composite Nanofibers for Use as Anode Material in Advanced Lithium-Ion Batteries AU - Li, Shuli AU - Fu, Kun AU - Xue, Leigang AU - Toprakci, Ozan AU - Li, Ying AU - Zhang, Shu AU - Xu, Guanjie AU - Lu, Yao AU - Zhang, Xiangwu AU - Hu, YH AU - Burghaus, U AU - Qiao, S T2 - Nanotechnology For Sustainable Energy DA - 2013/// PY - 2013/// VL - 1140 SP - 55-66 ER - TY - CONF TI - Novel Nanofibers for Biomedical Textiles C2 - 2013/3// C3 - Joint US EPA-NCSU Interactive Collaboration Forum and Poster Session DA - 2013/3// ER - TY - CONF TI - Hybrid PEMs Incorporated with Solid Superacidic Nanofibers C2 - 2013/4// C3 - 2013 MRS Spring Meeting & Exhibit DA - 2013/4// ER - TY - CONF TI - Flexible and Binder-Free Design: Nonwoven Structure Based Si Materials as Anodes for Lithium-Ion Batteries C2 - 2013/3// C3 - The 8th Annual NC State University Graduate Student Research Symposium DA - 2013/3// ER - TY - CONF TI - Nano in Lithium-Ion Battery C2 - 2013/6// C3 - FREEDM Systems Center Student Research Workshop DA - 2013/6// ER - TY - CONF TI - High-Power and High-Energy Electrochemical Electrodes and Supercapacitors C2 - 2013/11// C3 - Center for Dielectric Studies 2013 Fall Meeting DA - 2013/11// ER - TY - JOUR TI - Heat treatment of electrospun Polyvinylidene fluoride fibrous membrane separators for rechargeable lithium-ion batteries AU - Liang, Yinzheng AU - Cheng, Sichen AU - Zhao, Jianmeng AU - Zhang, Changhuan AU - Sun, Shiyuan AU - Zhou, Nanting AU - Qiu, Yiping AU - Zhang, Xiangwu T2 - Journal of Power Sources AB - Li2MnSiO4 has been considered as a promising cathode material with an extremely high theoretically capacity of 332 mAh g−1. However, due to its low intrinsic conductivity and poor structural stability, only about half of the theoretical capacity has been realized in practice and the capacity decays rapidly during cycling. To realize the high capacity and improve the cycling performance, Li2Mn0.8Fe0.2SiO4/carbon composite nanofibers were prepared by the combination of iron doping and electrospinning. X-ray diffraction, scanning electron microscope, and transmission electronic microscope were applied to characterize the Li2Mn0.8Fe0.2SiO4/carbon nanofibers. It was found that Li2Mn0.8Fe0.2SiO4 nanoparticles were embedded into continuous carbon nanofiber matrices, which formed free-standing porous mats that could be used as binder-free cathodes. The iron doping improved the conductivity and purity of the active material, and the carbon nanofiber matrix facilitated ion transfer and charge diffusion. As a result, Li2Mn0.8Fe0.2SiO4/carbon nanofiber cathodes showed promising improvement on reversible capacity and cycling performance. DA - 2013/10// PY - 2013/10// DO - 10.1016/j.jpowsour.2012.04.011 VL - 240 SP - 204-211 UR - https://doi.org/10.1016%2Fj.jpowsour.2013.04.019 KW - Li2MnSiO4 KW - Iron doping KW - Cathode KW - Electrospinning KW - Carbon nanofibers ER - TY - CONF TI - Fast and Low-Cost Production of Nanofibers by Centrifugal Spinning C2 - 2013/8// C3 - College of Textiles’ Composites Symposium DA - 2013/8// ER - TY - CONF TI - Aligned Carbon Nanotube-Silicon f Sheets: A Novel Nano-Architecture for Flexible Lithium-ion Battery Electrodes C2 - 2013/11// C3 - North Carolina American Chemical Society’s 127th Sectional Conference DA - 2013/11// ER - TY - CONF TI - Aligned Carbon Nanotube-Silicon Sheets: A Novel Nano-Architecture for Flexible Lithium-ion Battery Electrodes C2 - 2013/11// C3 - MRS/ASM/AVS/AReMS Meeting DA - 2013/11// ER - TY - CONF TI - Aligned Carbon Nanotube-Silicon Sheets: A Novel Nano-Architecture for Flexible Lithium-ion Battery Electrodes C2 - 2013/12// C3 - 2013 MRS Fall Meeting & Exhibit DA - 2013/12// ER - TY - JOUR TI - Submicrometre particle filtration with a dc activated plasma textile AU - Rasipuram, S C AU - Wu, M AU - Kuznetsov, I A AU - Kuznetsov, A V AU - Levine, J F AU - Jasper, W J AU - Saveliev, A V T2 - Journal of Physics D: Applied Physics AB - Plasma textiles are novel fabrics incorporating the advantages of cold plasma and low-cost non-woven or woven textile fabrics. In plasma textiles, electrodes are integrated into the fabric, and a corona discharge is activated within and on the surface of the fabric by applying high voltages above 10 kV between the electrodes. When the plasma textile is activated, submicrometre particles approaching the textile are charged by the deposition of ions and electrons produced by the corona, and then collected by the textile material. A stable plasma discharge was experimentally verified on the surface of the textile that was locally smooth but not rigid. A filtration efficiency close to 100% was observed in experiments conducted on salt particles with diameters ranging from 50 to 300 nm. Unlike conventional fibrous filters, the plasma textile provided uniform filtration in this range, without exhibiting a maximum particle penetration size. DA - 2013/// PY - 2013/// DO - 10.1088/0022-3727/47/2/025201 VL - 47 IS - 2 SP - 025201 KW - non-thermal plasmas KW - filtration KW - corona discharge KW - plasma textile ER - TY - BOOK TI - Simulation Modeling with SIMIO: A Workbook AU - Joines, J.A. AU - Roberts, S.D. DA - 2013/// PY - 2013/// ET - 3rd PB - Simio LLC Sewickley, PA ER - TY - JOUR TI - Thermal Annealing of Polymer Nanocomposites via Photothermal Heating: Effects on Crystallinity and Spherulite Morphology AU - Viswanath, Vidya AU - Maity, Somsubhra AU - Bochinski, Jason R. AU - Clarke, Laura I. AU - Gorga, Russell E. T2 - MACROMOLECULES AB - Metal nanoparticles embedded within polymeric systems can act as localized heat sources, facilitating in situ polymer processing. When irradiated with light resonant with the nanoparticle’s surface plasmon resonance (SPR), a nonequilibrium electron distribution is generated which rapidly transfers energy into the surrounding medium, resulting in a temperature increase in the immediate region around the particle. This work compares the utility of such photothermal heating versus traditional heating in gold nanoparticle/poly(ethylene oxide) nanocomposite films, crystallized from solution and the melt, which are annealed at average sample temperatures above the glass transition and below the melting point. For all temperatures, photothermally annealed samples reached maximum crystallinity and maximum spherulite size faster. Percentage crystallinity change under conventional annealing was analyzed using time–temperature superposition (TTS). Comparison of the TTS data with results from photothermal experiments enabled determination of an “effective dynamic temperature” achieved under photothermal heating which is significantly higher than the average sample temperature. Thus, the heterogeneous temperature distribution created when annealing with the plasmon-mediated photothermal effect represents a unique tool to achieve processing outcomes that are not accessible via traditional annealing. DA - 2013/11/12/ PY - 2013/11/12/ DO - 10.1021/ma401855v VL - 46 IS - 21 SP - 8596-8607 SN - 1520-5835 ER - TY - JOUR TI - The Effect of Hue on the Perception of Blackness Using Munsell Samples AU - Haslup, J. Reid Clonts AU - Shamey, Renzo AU - Hinks, David T2 - COLOR RESEARCH AND APPLICATION AB - Although black is an important color, the perception of black objects has not been systematically examined. The purpose of this work was to determine the influence of hue on the perception of preferred blackness. A set of 20 glossy low chroma Munsell sheets were purchased comprising a complete hue circle with a value and chroma of two and one, respectively (L* = 19.3–20.75, and C* = 3.66–6.58). The Munsell samples were divided into two interleaved groups: (5R, 5YR, 5Y, 5GY, 5G, 5BG, 5B, 5PB, 5P, and 5RP) and (10R, 10YR, 10Y, 10GY, 10G, 10BG, 10B, 10PB, 10P, and 10RP). Fifty color‐normal observers force‐ranked the two sets of 10 samples from “most like black” to “least like black.” Observers then assessed a set of six samples that represented the three samples from each set of 10 that the observer chose to be “most like black.” The 50 observers were found to have fairly good autoconcordance and concordance values. In repeat experiments observers agreed with themselves in 81% of the pairwise decisions, and they agreed with the grand mean rank 76% of the time. The blue–green samples (with Munsell hue notations 10G, 5BG, and 10BG) were most selected (and were considered blackest), followed by green, blue, and purple–blue. The samples selected the fewest times by any observer as being most black were the red samples. The grand mean rankings demonstrate that greenish to bluish blacks are perceived by the observers as “blacker” than yellowish and reddish blacks. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 423–428, 2013 DA - 2013/12// PY - 2013/12// DO - 10.1002/col.21744 VL - 38 IS - 6 SP - 423-428 SN - 1520-6378 KW - blackness KW - blackness preference KW - psychophysical assessment of blackness KW - blackness in Munsell system ER - TY - JOUR TI - Quasi-static and fatigue tensile behavior of a 3D rotary braided carbon/epoxy composite AU - Carvelli, Valter AU - Pazmino, Juan AU - Lomov, Stepan V. AU - Bogdanovich, Alexander E. AU - Mungalov, Dimitri D. AU - Verpoest, Ignaas T2 - JOURNAL OF COMPOSITE MATERIALS AB - This paper presents an experimental study of the quasi-static and fatigue behaviour of a three-dimensional braided carbon/epoxy composite. The study involves a three-dimensional braided carbon preform and composite samples produced at 3TEX Inc. on their 576-carrier rotary braiding machine. The first part of the paper describes the preform and composite sample fabrication procedures, the fiber volume fraction determination and the porosity evaluation using micro-computed tomography three-dimensional observation. The second part is devoted to experimental study of the quasi-static tensile response of the material, including the acoustic emission monitoring and the microscopic damage detection. The third part is dedicated to the fatigue tensile–tensile behaviour illustrated by the fatigue life curve and the micro-computed tomography images of the damage imparted after different number of cycles. The fourth part presents results of the quasi-static tensile tests of preliminarily cyclically loaded specimens. These results provide significant insight into the influence of the damage imparted during fatigue loading on the subsequent quasi-static behaviour. DA - 2013/11// PY - 2013/11// DO - 10.1177/0021998312463407 VL - 47 IS - 25 SP - 3195-3210 SN - 1530-793X KW - 3D braided composites KW - mechanical properties KW - fatigue ER - TY - JOUR TI - Methods and impact of reducing salt in dyeing cellulose: a case study with CI Direct Blue 90 AU - Jasper, Samuel M. AU - Jasper, Warren J. T2 - COLORATION TECHNOLOGY AB - The addition of large amounts of salt is one of the most important environmental problems in the dyeing of cellulosic fibres with direct or reactive dyes. This study was undertaken to determine an accurate and effective method for measuring the impact of salt on the dyeing process. This method has been applied to the case of CI D irect B lue 90 by utilising real‐time measurements of dye exhaustion for different salt and dye concentrations. Reductions in salt by a factor of 4 were achieved with no effect on the final shade. It is proposed that this method could be used to reduce the amount of salt for many other direct dyes, or to enable the dyer to quantify the trade‐off between time to final exhaustion and salt addition. DA - 2013/10// PY - 2013/10// DO - 10.1111/cote.12042 VL - 129 IS - 5 SP - 385-388 SN - 1478-4408 ER - TY - JOUR TI - High efficiency ultra-deep dyeing of cotton via mercerization and cationization AU - Fu, S. AU - Hinks, D. AU - Hauser, P. AU - Ankeny, M. T2 - Cellulose DA - 2013/// PY - 2013/// DO - 10.1007/s10570-013-0081-6 VL - 20 IS - 6 SP - 3101-3110 ER - TY - JOUR TI - Copper-Encapsulated Vertically Aligned Carbon Nanotube Arrays AU - Stano, Kelly L. AU - Chapla, Rachel AU - Carroll, Murphy AU - Nowak, Joshua AU - McCord, Marian AU - Bradford, Philip D. T2 - ACS Applied Materials & Interfaces AB - A new procedure is described for the fabrication of vertically aligned carbon nanotubes (VACNTs) that are decorated, and even completely encapsulated, by a dense network of copper nanoparticles. The process involves the conformal deposition of pyrolytic carbon (Py-C) to stabilize the aligned carbon-nanotube structure during processing. The stabilized arrays are mildly functionalized using oxygen plasma treatment to improve wettability, and they are then infiltrated with an aqueous, supersaturated Cu salt solution. Once dried, the salt forms a stabilizing crystal network throughout the array. After calcination and H2 reduction, Cu nanoparticles are left decorating the CNT surfaces. Studies were carried out to determine the optimal processing parameters to maximize Cu content in the composite. These included the duration of Py-C deposition and system process pressure as well as the implementation of subsequent and multiple Cu salt solution infiltrations. The optimized procedure yielded a nanoscale hybrid material where the anisotropic alignment from the VACNT array was preserved, and the mass of the stabilized arrays was increased by over 24-fold because of the addition of Cu. The procedure has been adapted for other Cu salts and can also be used for other metal salts altogether, including Ni, Co, Fe, and Ag. The resulting composite is ideally suited for application in thermal management devices because of its low density, mechanical integrity, and potentially high thermal conductivity. Additionally, further processing of the material via pressing and sintering can yield consolidated, dense bulk composites. DA - 2013/10/21/ PY - 2013/10/21/ DO - 10.1021/am402964e VL - 5 IS - 21 SP - 10774-10781 J2 - ACS Appl. Mater. Interfaces LA - en OP - SN - 1944-8244 1944-8252 UR - http://dx.doi.org/10.1021/am402964e DB - Crossref KW - carbon nanotube KW - nanocomposites KW - copper KW - CNT array KW - thermal management ER - TY - JOUR TI - Symmetric and Asymmetric Capillary Bridges between a Rough Surface and a Parallel Surface AU - Wang, Yongxin AU - Michielsen, Stephen AU - Lee, Hoon Joo T2 - LANGMUIR AB - Although the formation of a capillary bridge between two parallel surfaces has been extensively studied, the majority of research has described only symmetric capillary bridges between two smooth surfaces. In this work, an instrument was built to form a capillary bridge by squeezing a liquid drop on one surface with another surface. An analytical solution that describes the shape of symmetric capillary bridges joining two smooth surfaces has been extended to bridges that are asymmetric about the midplane and to rough surfaces. The solution, given by elliptical integrals of the first and second kind, is consistent with a constant Laplace pressure over the entire surface and has been verified for water, Kaydol, and dodecane drops forming symmetric and asymmetric bridges between parallel smooth surfaces. This solution has been applied to asymmetric capillary bridges between a smooth surface and a rough fabric surface as well as symmetric bridges between two rough surfaces. These solutions have been experimentally verified, and good agreement has been found between predicted and experimental profiles for small drops where the effect of gravity is negligible. Finally, a protocol for determining the profile from the volume and height of the capillary bridge has been developed and experimentally verified. DA - 2013/9// PY - 2013/9// DO - 10.1021/la401324f VL - 29 IS - 35 SP - 11028-11037 SN - 1520-5827 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000326128900008&KeyUID=WOS:000326128900008 ER - TY - JOUR TI - Preparation of antibacterial PVA and PEO nanofibers containing Lawsonia Inermis (henna) leaf extracts AU - Avci, H. AU - Monticello, R. AU - Kotek, R. T2 - JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION AB - Concerns about health issues and environmental pollution stimulate research to find new health and hygiene related products with healing properties and minimum negative effect on the environment. Development of new, natural antibacterial agents has become one of the most important research areas to combat some pathogens such as Gram- positive and Gram-negative bacteria, fungi, algae, yeast, and some microorganisms which cause serious human infections. Lawsonia Inermis (henna) leaf extracts for preparation of antibacterial poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA) nanofibers via electrospinning technique were investigated. PEO and PVA based electrospun fibers containing henna extract were verified by the appearance of FTIR peaks corresponding to the pure extract. Our study demonstrates that 2.793 wt.% Li in PVA and PEO based solutions showed bactericidal effects against Staphylococcus aureus and bacteriostatic action to Escherichia coli. Concentrations of henna leaf extract strongly impacted antibacterial activities against both bacteria. Henna leaves have a great potential to be used as a source of a potent eco-friendly antimicrobial agent. DA - 2013/11/1/ PY - 2013/11/1/ DO - 10.1080/09205063.2013.804758 VL - 24 IS - 16 SP - 1815-1830 SN - 1568-5624 KW - Lawsonia Inermis KW - henna KW - electrospinning KW - S. aureus KW - E. coli KW - PVA and PEO ER - TY - JOUR TI - Polymeric Systems Incorporating Plant Viral Nanoparticles for Tailored Release of Therapeutics AU - Honarbakhsh, Sara AU - Guenther, Richard H. AU - Willoughby, Julie A. AU - Lommel, Steven A. AU - Pourdeyhimi, Behnam T2 - ADVANCED HEALTHCARE MATERIALS AB - Therapeutic polylactide (PLA) nanofibrous matrices are fabricated by incorporating plant viral nanoparticles (PVNs) infused with fluorescent agents ethidium bromide (EtBr) and rhodamine (Rho), and cancer therapeutic doxorubicin (Dox). The native virus, Red clover necrotic mosaic virus (RCNMV), reversibly opens and closes upon exposure to the appropriate environmental stimuli. Infusing RCNMV with small molecules allows the incorporation of PVN(Active) into fibrous matrices via two methods: direct processing by in situ electrospinning of a polymer and PVNs solution or immersion of the matrix into a viral nanoparticle solution. Five organic solvents commonly in-use for electrospinning are evaluated for potential negative impact on RCNMV stability. In addition, leakage of rhodamine from the corresponding PVN(Rho) upon solvent exposure is determined. Incorporation of the PVN into the matrices are evaluated via transmission electron, scanning electron and fluorescent microscopies. Finally, the percent cumulative release of doxorubicin from both PLA nanofibers and PLA and polyethylene oxide (PEO) hybrid nanofibers demonstrate tailored release due to the incorporation of PVN(Dox) as compared to the control nanofibers with free Dox. Preliminary kinetic analysis results suggest a two-phase release profile with the first phase following a hindered Fickian transport mechanism for the release of Dox for the polymer-embedded PVNs. In contrast, the nanofiber matrices that incorporate PVNs through the immersion processing method followed a pseudo-first order kinetic transport mechanism. DA - 2013/7// PY - 2013/7// DO - 10.1002/adhm.201200434 VL - 2 IS - 7 SP - 1001-1007 SN - 2192-2659 KW - controlled release KW - drug delivery KW - nanofibers KW - plant viral nanoparticles KW - virus ER - TY - JOUR TI - Mechanisms and reactions during atomic layer deposition on polymers AU - Parsons, Gregory N. AU - Atanasov, Sarah E. AU - Dandley, Erinn C. AU - Devine, Christina K. AU - Gong, Bo AU - Jur, Jesse S. AU - Lee, Kyoungmi AU - Oldham, Christopher J. AU - Peng, Qing AU - Spagnola, Joseph C. AU - Williams, Philip S. T2 - COORDINATION CHEMISTRY REVIEWS AB - There is significant growing interest in atomic layer deposition onto polymers for barrier coatings, nanoscale templates, surface modification layers and other applications. The ability to control the reaction between ALD precursors and polymers opens new opportunities in ALD materials processing. It is well recognized that ALD on many polymers involves subsurface precursor diffusion and reaction which are not encountered during ALD on solid surfaces. This article reviews recent insights into chemical reactions that proceed during ALD on polymers, with particular focus on the common Al2O3 reaction sequence using trimethyl aluminum (TMA) and water. We highlight the role of different polymer reactive groups in film growth, and how the balance between precursor diffusion and reaction can change as deposition proceeds. As a strong Lewis acid, TMA forms adducts with Lewis base sites within the polymer, and the reactions that proceed are determined by the neighboring bond structure. Moreover, the Lewis base sites can be saturated by TMA, producing a self-limiting half-reaction within a three-dimensional polymer, analogous to a self-limiting half-reaction commonly observed during ALD on a solid planar surface. DA - 2013/12// PY - 2013/12// DO - 10.1016/j.ccr.2013.07.001 VL - 257 IS - 23-24 SP - 3323-3331 SN - 1873-3840 KW - Atomic layer deposition KW - Polymers KW - Thin films KW - Inorganic coatings KW - Al2O3 ER - TY - JOUR TI - Influence of cyclic versus acyclic oxygen-containing electron donor ancillary ligands on the photocurrent, photovoltage and photostability for high efficiency dye-sensitized solar cells AU - El-Shafei, A. AU - Hussain, M. AU - Islam, A. AU - Han, L. T2 - Journal of Materials Chemistry A AB - Three novel heteroleptic amphiphilic polypyridyl Ru-complexes, MH01, MH03, and MH05, with oxygen-containing-electron-donor stilbazole-based ancillary ligands were synthesized to study the influence of the cyclic-electron-donor (MH01), the presence of the cyclic electron donor coupled to acyclic electron-donor auxochromes (MH03) ortho to the CHCH bridge of stilbazole, and the presence of only acyclic electron-donor methoxy group (MH05) on molar extinction coefficient, light harvesting efficiency (LHE), ground and excited state oxidation potentials, and photovoltaic performance for DSSCs. Although MH05 has three electron donor methoxy groups, it achieved the lowest molar extinction coefficient of 18 250 M−1 cm−1 and exhibited the lowest photocurrent. The highest photocurrent density (JSC) was observed for the longest interatomic distance between the CHCH bridge of the stilbazole moiety and cyclic-electron-donor auxochromes (MH01). It was also shown that while incorporation of acyclic electron-donor auxochromes ortho to the CHCH bridge (MH03) has little effect on the ground and excited state oxidation potentials, λmax of the low energy MLCT, and molar absorptivity, the lowest photovoltage and %η were observed. When compared under the same experimental device conditions using 0.3 M tert-butylpyridine (TBP), only MH01-TBA achieved 18% more in JSC and 8.6% greater in η than the benchmark dye N719. To probe the interrelationship among the cyclic-vs.-acyclic oxygen-containing electron donors of the ancillary ligands, photocurrent and photovoltage of these dyes, the equilibrium molecular geometries of the ancillary ligands were calculated using DFT. The HOMO distribution on cyclic-vs.-acyclic electron donors and the position of OMe in the ancillary ligands rationalized the fundamental science behind the photovoltaic performance and photostability of these dyes. DA - 2013/// PY - 2013/// DO - 10.1039/c3ta12748f VL - 1 IS - 43 SP - 13679-13686 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84886923554&partnerID=MN8TOARS ER - TY - JOUR TI - Improving Poly(ethylene terephthalate) Through Self-nucleation AU - Joijode, Abhay S. AU - Hawkins, KaDesia AU - Tonelli, Alan E. T2 - MACROMOLECULAR MATERIALS AND ENGINEERING AB - Abstract As‐received poly(ethylene terephthalate) (asr‐PET) may be reorganized by precipitation from trifluoroacetic acid upon gradual addition to a large excess of rapidly stirred acetone (p‐PET). Unlike asr‐PET, p‐PET repeatedly crystallizes rapidly from the melt, and can be used in small quantities (a few %) as an effective self‐nucleating agent to control and improve the bulk semi‐crystalline morphology and properties of asr‐PET. Nuc‐PET film has significantly increased hardness and Young's modulus and is much less permeable to CO 2 , while its un‐drawn fibers exhibit higher tenacities and moduli. Because nuc‐PET contains no incompatible additives, it may be readily recycled. magnified image DA - 2013/11// PY - 2013/11// DO - 10.1002/mame.201200398 VL - 298 IS - 11 SP - 1190-1200 SN - 1439-2054 KW - crystallization KW - density and mechanical properties KW - nucleation KW - PET ER - TY - JOUR TI - Two-Stage Desorption-Controlled Release of Fluorescent Dye and Vitamin from Solution-Blown and Electrospun Nanofiber Mats Containing Porogens AU - Khansari, S. AU - Duzyer, S. AU - Sinha-Ray, S. AU - Hockenberger, A. S. AU - Yarin, A. L. AU - Pourdeyhimi, B. T2 - MOLECULAR PHARMACEUTICS AB - In the present work, a systematic study of the release kinetics of two embedded model drugs (one completely water soluble and one partially water soluble) from hydrophilic and hydrophobic nanofiber mats was conducted. Fluorescent dye Rhodamine B was used as a model hydrophilic drug in controlled release experiments after it was encapsulated in solution-blown soy-protein-containing hydrophilic nanofibers as well as in electrospun hydrophobic poly(ethylene terephthalate) (PET)-containing nanofibers. Vitamin B2 (riboflavin), a partially water-soluble model drug, was also encapsulated in hydrophobic PET-containing nanofiber mats, and its release kinetics was studied. The nanofiber mats were submerged in water, and the amount of drug released was tracked by fluorescence intensity. It was found that the release process saturates well below 100% release of the embedded compound. This is attributed to the fact that desorption is the limiting process in the release from biopolymer-containing nanofibers similar to the previously reported release from petroleum-derived polymer nanofibers. Release from monolithic as well as core-shell nanofibers was studied in the present work. Moreover, to facilitate the release and ultimately to approach 100% release, we also incorporated porogens, for example, poly(ethylene glycol), PEG. It was also found that the release rate can be controlled by the porogen choice in nanofibers. The effect of nanocracks created by leaching porogens on drug release was studied experimentally and evaluated theoretically, and the physical parameters characterizing the release process were established. The objective of the present work is a detailed experimental and theoretical investigation of controlled drug release from nanofibers facilitated by the presence of porogens. The novelty of this work is in forming nanofibers containing biodegradable and biocompatible soy proteins to facilitate controlled drug release as well as in measuring detailed quantitative characteristics of the desorption processes responsible for release of the model substance (fluorescent dye) and the vitamin (riboflavin) in the presence of porogens. DA - 2013/12// PY - 2013/12// DO - 10.1021/mp4003442 VL - 10 IS - 12 SP - 4509-4526 SN - 1543-8384 KW - controlled release KW - nanofibers KW - soy protein KW - porogens KW - desorption ER - TY - JOUR TI - Functional Dyes AU - El-Shafei, Ahmed AU - Islam, Ashraful AU - Akhtaruzzaman, Md. T2 - JOURNAL OF CHEMISTRY DA - 2013/// PY - 2013/// DO - 10.1155/2013/828910 VL - 2013 SP - SN - 2090-9071 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84897785813&partnerID=MN8TOARS ER - TY - JOUR TI - Aligned Carbon Nanotube-Silicon Sheets: A Novel Nano-architecture for Flexible Lithium Ion Battery Electrodes AU - Fu, Kun AU - Yildiz, Ozkan AU - Bhanushali, Hardik AU - Wang, Yongxin AU - Stano, Kelly AU - Xue, Leigang AU - Zhang, Xiangwu AU - Bradford, Philip D. T2 - ADVANCED MATERIALS AB - Aligned carbon nanotube sheets provide an engineered scaffold for the deposition of a silicon active material for lithium ion battery anodes. The sheets are low-density, allowing uniform deposition of silicon thin films while the alignment allows unconstrained volumetric expansion of the silicon, facilitating stable cycling performance. The flat sheet morphology is desirable for battery construction. DA - 2013/9// PY - 2013/9// DO - 10.1002/adma.201301920 VL - 25 IS - 36 SP - 5109-5114 SN - 1521-4095 UR - https://publons.com/publon/7178364/ KW - silicon KW - carbon nanotube KW - super-aligned KW - anode KW - lithium ion batteries ER - TY - JOUR TI - A simple method to encapsulate SnSb nanoparticles into hollow carbon nanofibers with superior lithium-ion storage capability AU - Xue, Leigang AU - Xia, Xin AU - Tucker, Telpriore AU - Fu, Kun AU - Zhang, Shu AU - Li, Shuli AU - Zhang, Xiangwu T2 - JOURNAL OF MATERIALS CHEMISTRY A AB - The practical use of high-capacity anodes in lithium-ion batteries generally suffers from significant volume changes upon lithium insertion and extraction. The volume changes induce cracks and loss of inter-particle electronic contact in the electrode, resulting in rapid capacity decay. The use of fiber-like materials to prevent cracks and accommodate volume changes is widely observed in many animal and human activities. Birds mix grass and feathers into mud to build nests, and humans in ancient times blended straw with mud to produce adobe bricks for housing construction. In view of this point, this research designed a porous nanofiber structure to resolve the unstable structure problem of anode materials. The three-dimensional network structure composed of nanofibers provides a highly elastic matrix to accommodate the volume changes of high-capacity Sn and Sb particles and pores around the active particles, induced by CO2 evolution, serve as an additional buffer zone for the volume changes. This unique structure prepared by using a new SnSb alloy precursor and a simple electrospinning technique leads to excellent lithium storage performance in terms of energy density, cycling stability, and rate capability. DA - 2013/// PY - 2013/// DO - 10.1039/c3ta12921g VL - 1 IS - 44 SP - 13807-13813 SN - 2050-7496 UR - https://publons.com/publon/7178344/ ER - TY - JOUR TI - Preservation of Cell Viability and Protein Conformation on Immobilization within Nanofibers via Electrospinning Functionalized Yeast AU - Canbolat, M. Fatih AU - Gera, Nimish AU - Tang, Christina AU - Monian, Brinda AU - Rao, Balaji M. AU - Pourdeyhimi, Behnam AU - Khan, Saad A. T2 - ACS APPLIED MATERIALS & INTERFACES AB - We investigate the immobilization of a model system of functionalized yeast that surface-display enhanced green fluorescent protein (eGFP) within chemically crosslinked polyvinyl alcohol (PVA) nanofibers. Yeast is incorporated into water insoluble nanofibrous materials by direct electrospinning with PVA followed by vapor phase chemical crosslinking of the polymer. Incorporation of yeast into the fibers is confirmed by elemental analysis and the viability is indicated by live/dead staining. Following electrospinning and crosslinking, we confirm that the yeast maintains its viability as well as the ability to express eGFP in the correct conformation. This method of processing functionalized yeast may thus be a powerful tool in the direct immobilization of properly folded, active enzymes within electrospun nanofibers with potential applications in biocatalysis. DA - 2013/10/9/ PY - 2013/10/9/ DO - 10.1021/am4022768 VL - 5 IS - 19 SP - 9349-9354 SN - 1944-8252 KW - electrospinning KW - nanofiber KW - protein KW - biocatalyst immobilization KW - yeast surface display ER - TY - JOUR TI - Polymer Nanocomposites Containing Carbon Nanofibers as Soft Printable Sensors Exhibiting Strain-Reversible Piezoresistivity AU - Toprakci, Hatice A. K. AU - Kalanadhabhatla, Saral K. AU - Spontak, Richard J. AU - Ghosh, Tushar K. T2 - ADVANCED FUNCTIONAL MATERIALS AB - Abstract Designed as flexible and extendable conductive print media for pervasive computing as strain sensors, nanocomposites composed of a plasticized thermoplastic or a cross‐linked elastomer and containing carbon nanofibers at concentrations just above the percolation threshold are observed to exhibit a uniquely strain‐reversible piezoresistive response upon application of quasi‐static tensile strain. At small strain levels, the electrical resistance of these nanocomposites reduces with increasing strain, indicative of negative piezoresistivity. Beyond a critical strain, however, the resistance reverses and increases with increasing strain, revealing the existence of a negative‐to‐positive piezoresistivity transition that is fully strain‐reversible and repeatable upon strain cycling. These characteristics imply that the nanocomposite morphologies are highly stable with little evidence of mechanical hysteresis. The mechanism underlying this transition is attributed to reorientation of high‐aspect‐ratio nanofibers (initially homogeneously dispersed) at low strains, followed by separation at high strains. While deposition of these nanocomposites as robust print coatings on textile fabric alters the percolation threshold, strain‐reversible piezoresistivity is retained, confirming that they are suitable as printable strain sensors. DA - 2013/11/26/ PY - 2013/11/26/ DO - 10.1002/adfm.201300034 VL - 23 IS - 44 SP - 5536-5542 SN - 1616-3028 KW - electronic textiles KW - piezoresistive nanocomposites KW - printable sensors KW - percolative elastomers KW - pervasive computing ER - TY - JOUR TI - Parameter study and characterization for polyacrylonitrile nanofibers fabricated via centrifugal spinning process AU - Lu, Yao AU - Li, Ying AU - Zhang, Shu AU - Xu, Guanjie AU - Fu, Kun AU - Lee, Hun AU - Zhang, Xiangwu T2 - EUROPEAN POLYMER JOURNAL AB - Electrospinning is currently the most popular method for producing polymer nanofibers. However, the low production rate and safety concern limit the practical use of electrospinning as a cost-effective nanofiber fabrication approach. Herein, we present a novel and simple centrifugal spinning technology that extrudes nanofibers from polymer solutions by using a high-speed rotary and perforated spinneret. Polyacrylonitrile (PAN) nanofibers were prepared by selectively varying parameters that can affect solution intrinsic properties and operational conditions. The resultant PAN nanofibers were characterized by SEM, and XRD. The correlation between fiber morphology and processing conditions was established. Results demonstrated that the fiber morphology can be easily manipulated by controlling the spinning parameters and the centrifugal spinning process is a facile approach for fabricating polymer nanofibers in a large-scale and low-cost fashion. DA - 2013/12// PY - 2013/12// DO - 10.1016/j.eurpolymj.2013.09.017 VL - 49 IS - 12 SP - 3834-3845 SN - 1873-1945 UR - https://publons.com/publon/7178360/ KW - Nanofibers KW - Centrifugal spinning KW - Electrospinning KW - Polyacrylonitrile KW - Diameter KW - Crystallinity ER - TY - CONF TI - Organic surface modifications on silicone elastomers: Impact on moisture vapor permeability and surface energy dynamics AU - Grewal, R. AU - Willoughby, J. A. AB - The purpose of this study was to observe the effects of organic surface modifications on silicone elastomers with respect to moisture vapor permeability properties as a function of both grafted moiety functionality and packing density. We utilized chemical vapor deposition and mechanical manipulation of the elastomer to deposit (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane and 3-aminopropyltrimethoxysilane. As expected, the chemical vapor deposition of both species altered the chemistry of the elastomer surface to more hydrophobic for the fluorinated silane and more hydrophilic for the amino - terminated silane in the absence of mechanical elongation during the modification. As previously demonstrated, increasing the packing density of the silanes by increasing the degree of tension on the substrate during activiation and deposition, resulted in an increase in the contact angle of water. This turned out to be true even for the hydrophilic species. In all modified samples, the moisture vapor permeability (MVP) decreased by about 50% and is attributed to the ultraviolet/ ozone activation step that created a silica-like layer. Despite the reduction in MVP, the modified elastomer films are still considered to have a high moisture vapor permeability on the order of 5·10-1 g·mm/m2·hr·kPa. C2 - 2013/// C3 - Progress in silicones and silicone-modified materials DA - 2013/// DO - 10.1021/bk-2013-1154.ch009 VL - 1154 SP - 113-132 ER - TY - JOUR TI - Maximizing Spontaneous Jet Density and Nanofiber Quality in Unconfined Electrospinning: The Role of Interjet Interactions AU - Roman, Michael P. AU - Thoppey, Nagarajan M. AU - Gorga, Russell E. AU - Bochinski, Jason R. AU - Clarke, Laura I. T2 - MACROMOLECULES AB - The interplay between an applied electric field and fluid properties was studied for a polymer solution forming high quality nanofibers via electrospinning. Unconfined electrospinning—in which a fluid thin film or bath exposed to an electric field spontaneously generates many parallel fiber-forming jets—is a practical approach to achieving a high fabrication rate of quality nanofibers as compared to traditional single-needle electrospinning. The density of fiber-forming jets is controlled by surface tension effects at the lowest applied voltages but by jet-to-jet interactions as the voltage amplitude is increased, resulting in an intermediate operating voltage level at which jet number is maximized. This general result is applicable to electric-field-driven fluid instabilities in a wide range of systems. The optimal voltage level occurs when interjet interactions begin to solely determine the characteristic jet spacing, and in this regime, compression of the cone-jet slightly chokes the feed rate, allowing high quality fibers to be formed when the maximum number of jets is present. Spontaneous jet deflection (here, from a linearly arranged source) results in a two-dimensional array at the collector which both minimizes interjet interactions and preserves fiber quality. DA - 2013/9/24/ PY - 2013/9/24/ DO - 10.1021/ma4013253 VL - 46 IS - 18 SP - 7352-7362 SN - 1520-5835 ER - TY - JOUR TI - Fabrication and Characterization of SiO2/PVDF Composite Nanofiber-Coated PP Nonwoven Separators for Lithium-Ion Batteries AU - Yanilmaz, Meltem AU - Chen, Chen AU - Zhang, Xiangwu T2 - JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS AB - ABSTRACT SiO 2 /polyvinylidene fluoride (PVDF) composite nanofiber‐coated polypropylene (PP) nonwoven membranes were prepared by electrospinning of SiO 2 /PVDF dispersions onto both sides of PP nonwovens. The goal of this study was to combine the good mechanical strength of PP nonwoven with the excellent electrochemical properties of SiO 2 /PVDF composite nanofibers to obtain a new high‐performance separator. It was found that the addition of SiO 2 nanoparticles played an important role in improving the overall performance of these nanofiber‐coated nonwoven membranes. Among the membranes with various SiO 2 contents, 15% SiO 2 /PVDF composite nanofiber‐coated PP nonwoven membranes provided the highest ionic conductivity of 2.6 × 10 −3 S cm −1 after being immersed in a liquid electrolyte, 1 mol L −1 lithium hexafluorophosphate in ethylene carbonate, dimethyl carbonate and diethyl carbonate. Compared with pure PVDF nanofiber‐coated PP nonwoven membranes, SiO 2 /PVDF composite fiber‐coated PP nonwoven membranes had greater liquid electrolyte uptake, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. SiO 2 /PVDF composite fiber‐coated PP nonwoven membrane separators were assembled into lithium/lithium iron phosphate cells and demonstrated high cell capacities and good cycling performance at room temperature. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51 , 1719–1726 DA - 2013/12/1/ PY - 2013/12/1/ DO - 10.1002/polb.23387 VL - 51 IS - 23 SP - 1719-1726 SN - 1099-0488 UR - https://publons.com/publon/7178359/ KW - battery separators KW - electrospinning KW - fibers KW - nanocomposites KW - nanoparticles KW - polyvinylidene fluoride KW - SiO2 nanoparticles ER - TY - JOUR TI - Effect of CVD carbon coatings on Si@CNF composite as anode for lithium-ion batteries AU - Fu, K. AU - Xue, L. G. AU - Yildiz, O. AU - Li, S. L. AU - Lee, H. AU - Li, Y. AU - Xu, G. J. AU - Zhou, L. AU - Bradford, P. D. AU - Zhang, Xiangwu AU - al. T2 - NANO ENERGY AB - Lithium-ion battery (LIB) anodes with high capacity and binder free structure were synthesized from carbon nanofibers that contained silicon nanoparticles (Si@CNF). The particle filled nonwoven structures were produced by an electrospinning and subsequent carbonization process. Pristine Si@CNF composites had Si nanoparticles exposed on the fiber surface. As produced, the Si nanoparticles could become detached from the nanofiber surface during cycling, causing severe structural damage and capacity loss. In order to prevent Si from detaching from the nanofiber surface, the Si@CNF composite was then treated with a thermal chemical vapor deposition (CVD) technique to make Si completely coated with a carbon matrix. The carbon coated Si@CNF (Si@CNF-C) composites were synthesized with different Si contents (10, 30, and 50 wt%) for different CVD treatment times (30, 60, and 90 min). It was found that the initial coulombic efficiency of Si@CNF-C could be increased via the amorphous carbon by stabilizing solid-electrolyte-interface (SEI) formation on surface. The capacity and cyclic stability were improved by the CVD carbon coating, especially for the 30 wt% Si@CNF-C composite with 90 min CVD coating, a CVD amorphous carbon coating of less than 1% by weight on Si@CNF composites contributed to more than 200% improvement in cycling performance. Results indicate that the CVD carbon coating is an effective approach to improve the electrochemical properties of Si@CNF composites making this a potential route to obtain high-energy density anode materials for LIBs. DA - 2013/9// PY - 2013/9// DO - 10.1016/j.nanoen.2013.03.019 VL - 2 IS - 5 SP - 976-986 SN - 2211-3282 UR - https://publons.com/publon/7178363/ KW - Lithium-ion battery anode KW - Silicon KW - Carbon nanofibers KW - CVD KW - SEI KW - Coulombic efficiency ER - TY - JOUR TI - Contact electrification of polymeric surfaces AU - Liu, L. AU - Oxenham, W. AU - Seyam, A. F. M. T2 - Indian Journal of Fibre & Textile Research DA - 2013/// PY - 2013/// VL - 38 IS - 3 SP - 265-269 ER - TY - JOUR TI - Cationic cotton, reservations to reality (vol 13, pg 56, 2013) AU - Farrell, M. J. AU - Hauser, P. J. T2 - AATCC Review DA - 2013/// PY - 2013/// VL - 13 IS - 6 SP - 19-19 ER - TY - JOUR TI - Biopolymer-Based Nanofiber Mats and Their Mechanical Characterization AU - Khansari, Shahrzad AU - Sinha-Ray, Suman AU - Yarin, Alexander L. AU - Pourdeyhimi, Behnam T2 - INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH AB - Nanofibers produced from plant- and animal-derived proteins using the solution-blowing method were collected and their mechanical properties were characterized and compared with those of synthetic polymer samples that were produced and collected similarly. Soy protein, zein, lignin, and cellulose acetate were the plant-derived proteins and silk protein (sericin) and bovine serum albumin were the animal-derived proteins used in the present work to form nanofibers by solution blowing. The aim of this work is to demonstrate that solution blowing can be successfully used to form nanotextured nonwovens from a number of biopolymers, which is of significant interest for a wide range of applications such as filtration, packaging, bioplastics and biomedical materials. Tensile tests were used to elucidate mechanical properties of such nanofiber mats. It was also shown that hot and cold drawing can be applied as a post-treatment to further enhance their mechanical performance. DA - 2013/10/30/ PY - 2013/10/30/ DO - 10.1021/ie402246x VL - 52 IS - 43 SP - 15104-15113 SN - 0888-5885 ER - TY - JOUR TI - A method for determining off-gassing of protective fabrics exposed to simulated flash fire conditions AU - Bradham, A. AU - Thompson, D. AU - Barker, R. AU - Morton-Aslanis, J. AU - Deaton, A. S. T2 - AATCC Review DA - 2013/// PY - 2013/// VL - 13 IS - 6 SP - 57-65 ER - TY - JOUR TI - Synthesis and characterization of xLi(2)MnO(3) center dot (1-x)LiMn1/3Ni1/3Co1/3O2 composite cathode materials for rechargeable lithium-ion batteries AU - Toprakci, Ozan AU - Toprakci, Hatice A. K. AU - Li, Ying AU - Ji, Liwen AU - Xue, Leigang AU - Lee, Hun AU - Zhang, Shu AU - Zhang, Xiangwu T2 - JOURNAL OF POWER SOURCES AB - Various xLi2MnO3·(1 − x)LiCo1/3Ni1/3Mn1/3O2 (x = 0.1, 0.2, 0.3, 0.4, and 0.5) cathode materials were prepared by the one-step sol–gel route. The structure of xLi2MnO3·(1 − x)LiCo1/3Ni1/3Mn1/3O2 composites was determined by X-ray diffraction analysis. The surface morphology and microstructure of xLi2MnO3·(1 − x)LiCo1/3Ni1/3Mn1/3O2 composites were characterized using scanning electron microscopy and transmission electron microscopy. Electrochemical performance of xLi2MnO3·(1 − x)LiCo1/3Ni1/3Mn1/3O2 composites was evaluated in terms of capacity, cycling performance and rate capability. Although the morphology and structure were found to be affected by the Li2MnO3 content, all composites showed an α-NaFeO2 structure with R3m space group. Electrochemical results showed that cells using 0.3Li2MnO3·0.7LiCo1/3Ni1/3Mn1/3O2 composites had good performance, in terms of large reversible capacity, prolonged cycling stability, and excellent rate capability. DA - 2013/11/1/ PY - 2013/11/1/ DO - 10.1016/j.jpowsour.2013.04.155 VL - 241 SP - 522-528 SN - 0378-7753 UR - https://publons.com/publon/674386/ KW - Lithium-ion batteries KW - Cathodes KW - Electrochemical performance KW - Li-rich KW - xLi(2)MnO(3)center dot(1-x)LiCo1/3Ni1/3Mn1/3O2 ER - TY - JOUR TI - Structure-Property Relationship of Amplified Spontaneous Emission in Organic Semiconductor Materials: TPD, DPABP, and NPB AU - Wu, Zhaoxin AU - Ma, Lin AU - Liu, Peng AU - Zhou, Caihua AU - Ning, Shuya AU - El-Shafei, Ahmed AU - Zhao, Xiang AU - Hou, Xun T2 - JOURNAL OF PHYSICAL CHEMISTRY A AB - N,N′-Diphenyl-N,N′-bis(3-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TPD) was demonstrated to be suitable for stimulated emission in doping and nondoping planar waveguide structure, but the mechanism for its lasing is of ambiguity. With the aim of providing a microsscopic picture for its lasing, we performed a combined experimental and theortical investigation of the absorption, photoluminescence (PL), and stimulated emission of TPD and other two similar molecules: 1,4-bis (diphenylamino)biphenyl (DPABP) and N,N′-diphenyl-N,N′-bis(1-naphthyl)-1,1′-biphenyl-4,4″-diamine (NPB). It was found that DPABP shows the same amplified spontaneous emission (ASE) characteristics as TPD, but NPB did not. In theory, density functional theory (DFT) and Franck–Condon Principle were used to analyze the molecular geometry in the electronic ground state as well as the optically excited state and the vibrational levels in electronic ground state, respectively. The calculation results show that for TPD and DPABP, several strongly elongated high-frequency modes (1199–1664 cm–1) in the carbon rings contribute to the distinct first vibronic sideband in the PL spectra, which form an effective four-level system for lasing. For NPB, when the peripheral toluene or benzene is replaced with naphthyl, a number of strongly elongated low-frequency modes (11–689 cm–1) deriving from naphthyl leads to a series of energy sublevels, which destroys the four-level system. Our results provided a new insight and better understanding into the lasing of organic molecules. DA - 2013/10/24/ PY - 2013/10/24/ DO - 10.1021/jp405692c VL - 117 IS - 42 SP - 10903-10911 SN - 1089-5639 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84886635488&partnerID=MN8TOARS ER - TY - JOUR TI - Single-component poly(epsilon-caprolactone) composites AU - Gurarslan, Alper AU - Shen, Jialong AU - Tonelli, Alan E. T2 - POLYMER AB - Abstract Non-covalently bonded crystalline inclusion compounds (ICs) have been formed by threading host cyclic starches, α-cyclodextrins (α-CDs), onto guest poly(e-caprolactone) (PCL) chains and by co-crystallization of guest PCL and host urea (U). PCLs were coalesced from both ICs by appropriate removal of the α-CD and U hosts. When added at low concentrations, PCL coalesced from its α-CD–IC served as an effective self-nucleating agent for the bulk crystallization of as-received PCL from the melt. Film sandwiches consisting of two layers of as-received (asr) (control), and one layer each of asr and self-nucleated (nuc) (composite) PCLs were produced by melt pressing. A composite sandwich consisting of a film of neat PCL coalesced from its U–IC (c-PCL) and a film of asr-PCL was also melt pressed. DSC showed that both composite films maintain their characteristic structures and properties even after melt-pressing them together. Both single component film sandwiches exhibited strong interfaces and better mechanical properties than the asr-PCL/asr-PCL control composite sandwiches. These results are similar to those previously obtained on similarly prepared nylon-6 (N-6) sandwich composites made with asr- and nuc-N-6 films with the same levels of crystallinity. However, while the elongation at break was greatly reduced in the asr-N-6/nuc-N-6 composite, asr-/asr-, asr-/c-, and asr-/nuc-, PCL/PCL-composites all showed similarly large elongations at break. The above room temperature and well below room temperature glass-transition temperatures of N-6 and PCL are likely the cause of their widely different elongations at break. DA - 2013/10/4/ PY - 2013/10/4/ DO - 10.1016/j.polymer.2013.08.017 VL - 54 IS - 21 SP - 5747-5753 SN - 1873-2291 KW - Cyclodextrin KW - Single polymer composite KW - Poly(epsilon-caprolactone) ER - TY - JOUR TI - Influence of Subsurface Hybrid Material Growth on the Mechanical Properties of Atomic Layer Deposited Thin Films on Polymers AU - Sun, Yujie AU - Padbury, Richard P. AU - Akyildiz, Halil I. AU - Goertz, Matthew P. AU - Palmer, Jeremy A. AU - Jur, Jesse S. T2 - CHEMICAL VAPOR DEPOSITION AB - Abstract The mechanical properties of atomic layer deposition (ALD) coatings play a key role in their long‐term use as encapsulation barriers for organic‐based, flexible, electronic devices. Nano‐indentation characteristics and flexure testing of nanometer‐scale alumina on polyamide 6 (PA6) films are investigated to determine the influence of a sub‐surface hybrid layer formed during the ALD process. This hybrid layer is observed to affect the mechanical performance of the thin films, in particular at lower processing temperatures. This work has important consequences on how ALD materials need to be applied and evaluated on polymers for application as encapsulation barrier layers. DA - 2013/6// PY - 2013/6// DO - 10.1002/cvde.201207042 VL - 19 IS - 4-6 SP - 134-141 SN - 1521-3862 KW - ALD nucleation KW - Flexibility KW - Hybrid layer KW - Mechanical properties KW - PA6 ER - TY - JOUR TI - Induced wetting of polytetrafluoroethylene by atomic layer deposition for application of aqueous-based nanoparticle inks AU - Halbur, Jonathan C. AU - Padbury, Richard P. AU - Jur, Jesse S. T2 - MATERIALS LETTERS AB - Atomic layer deposition of aluminum oxide is shown to control the surface energy and wetting properties of polytetrafluoroethylene (PTFE) films and membranes. Independent of deposition temperature, gradual and abrupt wetting transitions were observed for PTFE films and membranes, respectively. To assess the enhanced compatibility of treated PTFE substrates with nanoparticle inks, drop casting and inkjet printing of silver nanoparticle solutions are performed and analyzed by optical microscopy and time of flight secondary ion mass spectroscopy. Untreated PTFE substrates showed poor compatibility with the nanoparticle inks, drying in a coffee ring pattern, whereas aluminum oxide treated PTFE substrates exhibited uniform silver nanoparticle distribution after drying. DA - 2013/6/15/ PY - 2013/6/15/ DO - 10.1016/j.matlet.2013.03.063 VL - 101 SP - 25-28 SN - 1873-4979 KW - PTFE KW - Atomic layer deposition KW - Nanoparticle compatibility KW - Surface energy KW - Wetting KW - Al2O3 ER - TY - JOUR TI - Improvement of cyclability of silicon-containing carbon nanofiber anodes for lithium-ion batteries by employing succinic anhydride as an electrolyte additive AU - Li, Ying AU - Xu, Guanjie AU - Yao, Yingfang AU - Xue, Leigang AU - Zhang, Shu AU - Lu, Yao AU - Toprakci, Ozan AU - Zhang, Xiangwu T2 - JOURNAL OF SOLID STATE ELECTROCHEMISTRY DA - 2013/5// PY - 2013/5// DO - 10.1007/s10008-013-2005-7 VL - 17 IS - 5 SP - 1393-1399 SN - 1433-0768 UR - https://publons.com/publon/674383/ KW - Electrospinning KW - Carbon nanofiber KW - Si nanoparticle KW - Succinic anhydride KW - Lithium-ion batteries ER - TY - JOUR TI - High-performance Sn/Carbon Composite Anodes Derived from Sn(II) Acetate/Polyacrylonitrile Precursors by Electrospinning Technology AU - Li, Shuli AU - Xue, Leigang AU - Fu, Kun AU - Xia, Xin AU - Zhao, Chengxin AU - Zhang, Xiangwu T2 - CURRENT ORGANIC CHEMISTRY AB - Sn/carbon composite nanofibers with various compositions were prepared from Sn(II) acetate/polyacrylonitrile (PAN) precursors by a combination of electrospinning and carbonization methods, and their potential use as anode materials for rechargeable lithiumion batteries was investigated. The composite electrode derived from 20 wt% Sn(II) acetate/PAN precursor showed excellent electrochemical properties, including a large reversible capacity of 699 mAh g‾1 and a high capacity retention of 83% in 50 cycles. Sn/carbon composite nanofibers exhibited enhanced electrochemical performance ascribing to the combination of the properties of both Sn nanoparticles (large Li storage capability) and carbon matrices (long cycle life), and therefore could be potentially used in high-energy rechargeable lithium-ion batteries. Keywords: Tin, tin(II) acetate, Composite nanofiber, Electrospinning, Lithium-ion battery. DA - 2013/7// PY - 2013/7// DO - 10.2174/1385272811317130011 VL - 17 IS - 13 SP - 1448-1454 SN - 1385-2728 UR - https://publons.com/publon/7178342/ KW - Tin KW - tin(II) acetate KW - Composite nanofiber KW - Electrospinning KW - Lithium-ion battery ER - TY - JOUR TI - Comparison of the performance of inverse transformation methods from OSA-UCS to CIEXYZ AU - Cao, Renbo AU - Trussell, H. Joel AU - Shamey, Renzo T2 - JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION AB - The Optical Society of America’s Uniform Color Scales (OSA-UCS) is one of the color spaces that most closely approximate a “true” uniform color space. Different techniques have been used to convert OSA-UCS-based color specification parameters, L, j, and g, to the CIE tristimulus values, X, Y, and Z. However, none of these methods provides a direct method of inverting OSA-UCS to CIEXYZ values. Thus, numerical algorithms, such as the Newton–Raphson method, have been employed to obtain the transformations. The relative low accuracy and long computation time of this method makes it undesirable for practical applications. An artificial neural network (ANN) was employed to convert OSA-UCS to CIEXYZ. Its performance was compared with that of numerical methods. After optimization, ANN gave a better performance with a mean error (ΔEXYZ) of 1.0×10−4 and a conversion time of less than 1 s for 1891 samples. DA - 2013/8// PY - 2013/8// DO - 10.1364/josaa.30.001508 VL - 30 IS - 8 SP - 1508-1515 SN - 1520-8532 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84882949094&partnerID=MN8TOARS ER - TY - JOUR TI - Blowing drops off a filament AU - Sahu, R. P. AU - Sinha-Ray, S. AU - Yarin, A. L. AU - Pourdeyhimi, B. T2 - Soft Matter AB - The first part of this work is devoted to the experimental study of oil drop motion along a filament due to the parallel air jet blowing. The drop displacement and velocity along the filament are measured. A number of accompanying phenomena are observed. These include drop stick–slip motion and shape oscillations, shedding of a tail along the filament, the tail capillary instability and drop recoil motion. The experimental observations are rationalized in the framework of several simplified models, and the origin of several observed phenomena is elucidated. In the second part of this work, experiments with cross-flow of the surrounding gas relative to the filament with an oil drop on it are conducted, with the gas velocity being in the 7.23 to 22.7 m s−1 range. The Weber number varied from 2 to 40 and the Ohnesorge number was in the 0.07 to 0.8 range. The lower and upper critical Weber numbers were introduced to distinguish between the beginning of the drop blowing off the filament and the onset of the bag-stamen drop breakup. The range of the Weber number between these two critical values is filled with three types of vibrational breakup: V1 (a balloon-like drop being blown off), V2 (a drop on a single stamen being blown off), and V3 (a drop on a double stamen being blown off). At still higher values of the Weber number, the bag-stamen breakup can be replaced by the bag type of breakup depending on a slight difference in the blowing speed, or the former and the latter can become intermittent depending on the drop asymmetry relative to the filament. The Weber number/Ohnesorge number plane was delineated into domains corresponding to different breakup regimes, the statistics of the residual liquid portion left on a filament was established and drop hopping across neighboring filaments was studied. DA - 2013/// PY - 2013/// DO - 10.1039/c3sm50618e VL - 9 IS - 26 SP - 6053 J2 - Soft Matter LA - en OP - SN - 1744-683X 1744-6848 UR - http://dx.doi.org/10.1039/c3sm50618e DB - Crossref ER - TY - JOUR TI - SIMS analysis of zinc oxide LED structures: quantification and analysis issues AU - Stevie, F. A. AU - Maheshwari, P. AU - Pierce, J. M. AU - Adekore, B. T. AU - Griffis, D. P. T2 - SURFACE AND INTERFACE ANALYSIS AB - Zinc oxide (ZnO) is a wide band gap semiconductor that shows great promise for development of light emitting diode structures. Interest in this technology has increased significantly, but even though controlled n-type doping can be readily achieved, p-type doping has been difficult. Numerous potential p-type dopants were investigated in this SIMS study using a CAMECA IMS-6F. The dopants and other elements of interest were quantified by use of ion implantation into ZnO substrates. Relative sensitivity factor values were obtained for H, Li, N, F, Na, Mg, Al, Si, K, Ga, As, Se, Ag, Cd, Te. Sample charging was encountered for some specimens, and adjacent electron neutralization procedures were employed. ZnO structures were prepared and subsequently analyzed with both O2+ and Cs+ primary beams. Depth profiles exposed a number of analysis issues. Because of the large number of elements, especially those at low atomic number, that were present in the structures, many mass interferences were encountered. Ag in particular was very difficult to monitor. Matrix effects were also noted, especially when high Mg doping was used. The need to monitor Al, Na, and K in the near surface region required analysis without conductive Au coating to reduce contamination. With careful choice of secondary ion species, it was possible to monitor the elements of primary interest using O2+ primary beam. SIMS demonstrated the ability to characterize the layers in the ZnO structure, including quantum wells, and to determine dopant and contaminant levels. Copyright © 2012 John Wiley & Sons, Ltd. DA - 2013/1// PY - 2013/1// DO - 10.1002/sia.4919 VL - 45 IS - 1 SP - 352-355 SN - 1096-9918 KW - depth profiling KW - ZnO KW - RSFs ER - TY - JOUR TI - Quasi-static tensile behavior and damage of carbon/epoxy composite reinforced with 3D non-crimp orthogonal woven fabric AU - Bogdanovich, Alexander E. AU - Karahan, Mehmet AU - Lomov, Stepan V. AU - Verpoest, Ignaas T2 - MECHANICS OF MATERIALS AB - This paper presents a comprehensive experimental study and detailed mechanistic interpretations of the tensile behavior of one representative 3D non-crimp orthogonal woven (3DNCOW) carbon/epoxy composite. The composite is tested under uniaxial in-plane tensile loading in the warp, fill and ±45° bias directions. An “S-shape” nonlinearity observed in the stress–strain curves is explained by the concurrent contributions of inherent carbon fiber stiffening (“non-Hookean behavior”), fiber straightening, and gradual damage accumulation. Several approaches to the determination of a single-value Young’s modulus from a significantly nonlinear stress–strain curve are discussed and the best approach recommended. Also, issues related to the experimental determination of effective Poisson’s ratios for this class of composites are discussed, and their possible resolution suggested. The observed experimental values of the warp- and fill-directional tensile strengths are much higher than those typically obtained for 3D interlock weave carbon/epoxy composites while the nonlinear material behavior observed for the ±45°-directional tensile loading is in a qualitative agreement with the earlier results for other textile composites. Results of the damage initiation and progression, monitoried by means of acoustic emission, full-field strain optical measurements, X-rays and optical microscopy, are illustrated and discussed in detail. The damage modes at different stages of the increasing tensile loading are analyzed, and the principal progressive damage mechanisms identified, including the characteristic crack patterns developed at each damage stage. It is concluded that significant damage initiation of the present material occurs in the same strain range as in traditional cross-ply laminates, while respective strain range for other previously studied carbon/epoxy textile composites is significantly lower. Overall the revealed advantages in stiffness, strength and progressive damage behavior of the studied composite are mainly attributed to the absence of crimp and only minimal fiber waviness in the reinforcing 3DNCOW preform. DA - 2013/8/1/ PY - 2013/8/1/ DO - 10.1016/j.mechmat.2013.03.005 VL - 62 SP - 14-31 SN - 1872-7743 KW - Mechanical properties KW - 3D woven composite KW - Tensile loading KW - Elastic properties KW - Strength KW - Damage initiation and development ER - TY - JOUR TI - Quality variables of meltblown submicron filter materials AU - Shim, W. S. AU - Lee, D. W. T2 - Indian Journal of Fibre & Textile Research DA - 2013/// PY - 2013/// VL - 38 IS - 2 SP - 132-137 ER - TY - JOUR TI - Novel elastomeric fabrics for burn pressure garments using silver antimicrobial agents AU - Varan, N. Y. AU - Gursoy, N. C. AU - King, M. W. AU - Hauser, P. J. T2 - Tekstil ve Konfeksiyon DA - 2013/// PY - 2013/// VL - 23 IS - 1 SP - 38-42 ER - TY - JOUR TI - Multi-fiber needle-punched nonwoven composites: Effects of heat treatment on sound absorption performance AU - Yilmaz, Nazire Deniz AU - Powell, Nancy B. AU - Banks-Lee, Pamela AU - Michielsen, Stephen T2 - JOURNAL OF INDUSTRIAL TEXTILES AB - Nonwovens have been increasingly used in car interiors for noise reduction. Most of these nonwovens are subjected to thermal treatments to give the nonwovens their final three-dimensional forms. Therefore, it became crucial to investigate the effects of thermal treatment on sound absorption characteristics of nonwovens. In this study, the effects of the material and treatment parameters on airflow resistivity and normal-incidence sound absorption coefficient of thermally treated three-layered nonwoven composites have been studied. The material parameters included fiber size and porosity. The treatment factors included the temperature and duration. The thermally treated three-layered nonwoven composites are classified into three types based on the material content and fiber blend. Sandwich structures consisting of polylactide/hemp/polylactide and polypropylene/glassfiber/polypropylene layers were called LHL and PGP, respectively. The sample which consisted of three layers of an intimate blend of polypropylene-glassfiber was named as PGI. Both temperature and duration of thermal treatment have been found to affect air flow resistivity and sound absorption. An increase in air flow resistivity and a decrease in sound absorption have been detected with heat treatment. A similarity has been observed between the thermal behaviors of PGP and PGI, which included the same thermoplastic polymer fiber. Variation in air flow resistivity of sandwich structure nonwoven composites increased with the increase in temperature, which was not observed in the intimate blend ones. The air flow resistivity of heat-treated nonwovens followed a steeper trend compared to unheated nonwovens per change in material parameters. In terms of treatment parameters, the difference between the thermal treatment and the melting point of the thermoplastics constituent of the nonwoven composite was found to be a significant factor on sound absorption. This effect of treatment temperature on sound absorption changed with treatment duration. The sound absorptive characteristic of the nonwoven composites in terms of sound frequency underwent a change with thermal treatment due to the structural changes with exposure to high temperature. DA - 2013/10// PY - 2013/10// DO - 10.1177/1528083712452899 VL - 43 IS - 2 SP - 231-246 SN - 1530-8057 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000324590000006&KeyUID=WOS:000324590000006 KW - Sound absorption KW - heat treatment KW - composite KW - biodegradable ER - TY - JOUR TI - Masculinizing Effect of Background Color and Cortisol in a Flatfish with Environmental Sex-Determination AU - Mankiewicz, Jamie L. AU - Godwin, John AU - Holler, Brittany L. AU - Turner, Poem M. AU - Murashige, Ryan AU - Shamey, Renzo AU - Daniels, Harry V. AU - Borski, Russell J. T2 - INTEGRATIVE AND COMPARATIVE BIOLOGY AB - Environmental sex-determination (ESD) is the phenomenon by which environmental factors regulate sex-determination, typically occurring during a critical period of early development. Southern flounder (Paralichthys lethostigma) exhibit temperature-dependent sex-determination that appears to be restricted to the presumed XX female genotype with the extremes of temperature, both high and low, skewing sex ratios toward males. In order to evaluate other environmental factors that may influence sex-determination, we investigated the influence of background color and cortisol on sex-determination in southern flounder. Experiments involving three sets of tanks, each painted a different color, were conducted at different temperatures using southern flounder of mixed XX–XY genotype. The studies involved rearing juvenile southern flounder in either black, gray, or blue tanks and sex-determination was assessed by gonadal histology. In both studies, blue tanks showed significant male-biased sex ratios (95 and 75% male) compared with black and gray tanks. The stress corticosteroid cortisol may mediate sex-determining processes associated with environmental variables. Cortisol from the whole body was measured throughout the second experiment and fishes in blue tanks had higher levels of cortisol during the period of sex-determination. These data suggest that background color can be a cue for ESD, with blue acting as a stressor during the period of sex-determination, and ultimately producing male-skewed populations. In a separate study using XX populations of southern flounder, cortisol was applied at 0, 100, or 300 mg/kg of gelatin-coated feed. Fish were fed intermittently prior to, and just through, the period of sex-determination. Levels of gonadal P450 aromatase (cyp19a1) and forkhead transcription factor L2 (FoxL2) messenger RNA (mRNA) were measured by qRT–PCR as markers for differentiation into females. Müllerian-inhibiting substance mRNA was used as a marker of males’ gonadal development. Control fish showed female-biased sex ratios approaching 100%, whereas treatment with 100 mg/kg cortisol produced 28.57% females and treatment with 300 mg/kg cortisol produced only 13.33% females. These results suggest that cortisol is a critical mediator of sex-determination in southern flounder by promoting masculinization. This linkage between the endocrine stress axis and conserved sex-determination pathways may provide a mechanism for adaptive modification of sex ratio in a spatially and temporally variable environment. DA - 2013/10// PY - 2013/10// DO - 10.1093/icb/ict093 VL - 53 IS - 4 SP - 755-765 SN - 1557-7023 ER - TY - JOUR TI - Glass-transition temperatures of nanostructured amorphous bulk polymers and their blends AU - Joijode, Abhay S. AU - Antony, Gerry J. AU - Tonelli, Alan E. T2 - JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS AB - ABSTRACT Nanostructured amorphous bulk polymer samples were produced by processing them with small molecule hosts. Urea (U) and gamma‐cyclodextrin (γ‐CD) were utilized to form crystalline inclusion compounds (ICs) with low and high molecular weight as‐received (asr‐) poly(vinyl acetate) (PVAc), poly(methyl methacrylate) (PMMA), and their blends as included guests. Upon careful removal of the host crystalline U and γ‐CD lattices, nanostructured coalesced (c‐) bulk PVAc, PMMA, and PVAc/PMMA blend samples were obtained, and their glass‐transition temperatures, T g s, measured. In addition, non‐stoichiometric (n‐s)‐IC samples of each were formed with γ‐CD as the host. The T g s of the un‐threaded, un‐included portions of their chains were observed as a function of their degree of inclusion. In all the cases, these nanostructured PVAc and PMMA samples exhibited T g s elevated above those of their as‐received and solution‐cast samples. Based on their comparison, several conclusions were reached concerning how their molecular weights, the organization of chains in their coalesced samples, and the degree of constraint experienced by un‐included portions of their chains in (n‐s)‐γ‐CD‐IC samples with different stoichiometries affect their chain mobilities and resultant T g s. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 1041–1050 DA - 2013/7/1/ PY - 2013/7/1/ DO - 10.1002/polb.23306 VL - 51 IS - 13 SP - 1041-1050 SN - 1099-0488 KW - amorphous KW - blending KW - blends KW - glass transition KW - nano-structured KW - polymer glass-transitions ER - TY - JOUR TI - Conferring durable antimicrobial properties on nonwoven polypropylene via plasma-assisted graft polymerization of DADMAC AU - Mazloumpour, Maryam AU - Malshe, Priya AU - El-Shafei, Ahmed AU - Hauser, Peter T2 - SURFACE & COATINGS TECHNOLOGY AB - Spunbond nonwoven polypropylene (SB-PP), commonly used for hygienic products, was treated with diallyldimethylammonium chloride (DADMAC) to confer antimicrobial properties. Atmospheric pressure glow discharge plasma was used to induce free radical chain growth polymerization of DADMAC monomer onto the SB-PP in the presence of a crosslinker, which produced a graft polymerized network on the fabric with durable antimicrobial properties. The effects of different DADMAC concentrations and plasma operating condition parameters including the RF power (400–800 W) and the time of plasma exposure (0–120 s) were studied and the optimum treatment conditions were identified by determining the surface charge density on the treated fabrics. The presence of grafted poly-DADMAC on the polypropylene surface was confirmed using SEM, FT-IR and TOF-SIMS techniques. Antibacterial performance was investigated using the AATCC Test Method 100 for both gram positive and gram negative bacteria, and the antimicrobial test results showed 6 log reductions in the number of bacterial activities of Klebsiella pneumoniae and Staphylococcus aureus on the SB-PP samples, which is unprecedented. DA - 2013/6/15/ PY - 2013/6/15/ DO - 10.1016/j.surfcoat.2013.02.022 VL - 224 SP - 1-7 SN - 0257-8972 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84876729566&partnerID=MN8TOARS KW - Spunbond polypropylene KW - DADMAC KW - Antimicrobial KW - Atmospheric plasma KW - Graft polymerization ER - TY - JOUR TI - Bi-layer Al2O3/ZnO atomic layer deposition for controllable conductive coatings on polypropylene nonwoven fiber mats AU - Sweet, William J., III AU - Jur, Jesse S. AU - Parsons, Gregory N. T2 - JOURNAL OF APPLIED PHYSICS AB - Electrically conductive zinc oxide coatings are applied to polypropylene nonwoven fiber mats by atomic layer deposition (ALD) at 50–155 °C. A low temperature (50 °C) aluminum oxide ALD base layer on the polypropylene limits diffusion of diethyl zinc into the polypropylene, resulting in ZnO layers with properties similar to those on planar silicon. Effective conductivity of 63 S/cm is achieved for ZnO on Al2O3 coated polypropylene fibers, and the fibers remain conductive for months after coating. Without the Al2O3 precoating, the effective conductivity was much smaller, consistent with precursor diffusion into the polymer and sub-surface ZnO nucleation. Mechanical robustness tests showed that conductive samples bent around a 6 mm radius maintained up to 40% of the pre-bending conductivity. Linkages between electrical conductivity and mechanical performance will help inform materials choice for flexible and porous electronics including textile-based sensors and antennas. DA - 2013/5/21/ PY - 2013/5/21/ DO - 10.1063/1.4804960 VL - 113 IS - 19 SP - SN - 0021-8979 ER - TY - JOUR TI - Aligned carbon nanotube sheet high efficiency particulate air filters AU - Yildiz, Ozkan AU - Bradford, Philip D. T2 - CARBON AB - Aerosol filters, made with conventional micro-fiber fabrics, are designed to efficiently capture small particles from the air. Filters constructed of nano-fiber fabric structures provide even greater filtration efficiency than conventional micro-fiber fabrics due to their higher surface area and smaller pore size. Carbon nanotubes (CNTs) are very small diameter fibers that have the potential to be integrated into filters to further increase particle capture efficiency. In this study, CNT sheets, drawn from millimeter tall CNT arrays, were integrated between traditional micro-fiber fabrics to produce aerosol filters. The filtration performance of the novel filters showed that when the number of CNTs layers increased, the filtration efficiency increased dramatically, while the pressure drop also increased. In order to meet high efficiency particulate air (HEPA) filter requirements with a reasonable pressure drop, CNTs were laid in a cross-plied structure within the filter. The results demonstrated that the three layer cross-ply structure provided 99.98% filtration efficiency at 0.3 μm particle size at a 10 cm/s face velocity, making it a viable method for producing low basis weight HEPA filters utilizing CNTs as the main filtration component. DA - 2013/11// PY - 2013/11// DO - 10.1016/j.carbon.2013.07.066 VL - 64 SP - 295-304 SN - 1873-3891 ER - TY - JOUR TI - Synthesis and properties of Li2MnO3-based cathode materials for lithium-ion batteries AU - Xue, Leigang AU - Zhang, Shu AU - Li, Shuli AU - Lu, Yao AU - Toprakci, Ozan AU - Xia, Xin AU - Chen, Chen AU - Hu, Yi AU - Zhang, Xiangwu T2 - JOURNAL OF ALLOYS AND COMPOUNDS AB - Lithium-ion batteries have been wildly used in various portable electronic devices and the application targets are currently moving from small-sized mobile devices to large-scale electric vehicles and grid energy storage. Therefore, lithium-ion batteries with higher energy densities are in urgent need. For high-energy cathodes, Li2MnO3–LiMO2 layered–layered (M = Mn, Co, Ni) materials are of significant interest due to their high specific capacities over wide operating potential windows. Here, three Li2MnO3-based cathode materials with α-NaFeO2 structure were prepared by a facile co-precipitation method and subsequent heat treatment. Among these three materials, 0.3Li2MnO3·0.5LiMn0.5Ni0.5O2·0.2LiCoO2 shows the best lithium storage capability. This cathode material is composed of uniform nanosized particles with diameters ranging from 100 to 200 nm, and it could be charged to a high cutoff potential to extract more lithium, resulting in a high capacity of 178 mAh g−1 between 2.0 and 4.6 V with almost no capacity loss over 100 cycles. DA - 2013/11/15/ PY - 2013/11/15/ DO - 10.1016/j.jallcom.2013.07.029 VL - 577 SP - 560-563 SN - 1873-4669 UR - https://publons.com/publon/674387/ KW - Cathode material KW - Li2MnO3 KW - High capacity KW - Structure stability KW - Cycling performance ER - TY - JOUR TI - Graphene-coated pyrogenic carbon as an anode material for lithium battery AU - Zhang, Ming AU - Gao, Bin AU - Li, Ying AU - Zhang, Xiangwu AU - Hardin, Ian R. T2 - CHEMICAL ENGINEERING JOURNAL AB - Abstract In this work, cotton fibers and pyrene-dispersed graphene sheets were used to produce graphene-coated pyrogenic carbon as an anode material for lithium battery. The graphene sheets were wrapped around the cotton fibers by simply dipping the fabric in a graphene/pyrene-derivative suspension. And then the cotton/graphene textile was annealed at 700 °C in a quartz tube furnace under Ar flow conditions. During the annealing process, the gaps between separated graphene sheets were “soldered” by “glue” molecules (aromatic molecular surfactant) to form graphene-coated pyrogenic carbon. Because of the unique electric properties of the graphene “skin” on the pyrogenic carbon, the flexible graphene-coated pyrogenic carbon showed relatively large storage capacity to lithium. Galvanostatic charge–discharge experiments also showed that the graphene-coated pyrogenic carbon electrode provided a reversible discharge capacity as high as 288 mA h g−1 even after 50 cycles and thus can be used an anode material in lithium battery. DA - 2013/8/1/ PY - 2013/8/1/ DO - 10.1016/j.cej.2013.06.025 VL - 229 SP - 399-403 SN - 1385-8947 UR - https://publons.com/publon/7178361/ KW - Graphene KW - Pyrogenic carbon KW - Cotton fibers KW - Annealing KW - Lithium battery ER - TY - JOUR TI - Effects of surfactants on the microstructures of electrospun polyacrylonitrile nanofibers and their carbonized analogs AU - Aykut, Yakup AU - Pourdeyhimi, Behnam AU - Khan, Saad A. T2 - JOURNAL OF APPLIED POLYMER SCIENCE AB - ABSTRACT In this study, the influence of surfactants on the processability of electrospun polyacrylonitrile (PAN) nanofibers and their carbonized analogs was investigated. The surfactants employed in this effort are Triton X‐100 (nonionic surfactant, SF‐N), sodium dodecyl sulfate (SDS) (anionic surfactant, SF‐A), and hexadecyltrimethylammonium bromide (HDTMAB) (cationic surfactant, SF‐C). Interactions between electrospun PAN and the surfactants, reflected in effects on as‐spun and carbonized nanofiber morphologies and microstructures, were explored. The results show that uniform nanofibers are obtained when cationic and anionic surfactants (surfactant free and nonionic surfactants) are utilized in the preparation of electrospun PAN. In contrast, a bead‐on‐a‐string morphology results when the aniconic and cationic surfactants are present, and defect structure is enhanced with cationic surfactant addition. Moreover, fiber breakage is observed when the nonionic surfactant Triton X‐100 is employed for electrospinning. After carbonizaition, the PAN polymers were observed to have less ordered structures with addition of any type of surfactant used for electrospinning and the disorder becomes more pronounced when the anionic surfactant is utilized. Owing to the fact that microstructure defects create midband gap states that enable more electrons to be emitted from the fiber, an enhancement of electron emission is observed for PAN electrospun in the presence of the anionic surfactant. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3726–3735, 2013 DA - 2013/12/5/ PY - 2013/12/5/ DO - 10.1002/app.39637 VL - 130 IS - 5 SP - 3726-3735 SN - 1097-4628 KW - electrospinning KW - nanostructured polymers KW - morphology ER - TY - JOUR TI - Effect of DMDBS (3: 2, 4-bis(3,4-dimethyldibenzylidene) sorbitol) and NA11 (sodium 2,2-methylene-bis(4,6-di-tertbutylphenyl)-phosphate) on electret properties of polypropylene filaments AU - Kilic, Ali AU - Shim, Eunkyoung AU - Yeom, Bong Yeol AU - Pourdeyhimi, Behnam T2 - JOURNAL OF APPLIED POLYMER SCIENCE AB - ABSTRACT Polypropylene (PP) composite filaments containing two different nucleating agents—DMDBS (3 : 2, 4‐bis(3,4‐dimethyldibenzylidene) sorbitol) and NA11 (sodium 2,2′‐methylene‐bis(4,6‐di‐tertbutylphenyl)‐phosphate) were melt spun to modify polymer electrostatic charging characteristics. Sample filaments were charged with a corona instrument and their surface potentials were measured. Initial surface potential as well as potential stability was monitored through an accelerated decay procedure. NA11 was found to be more efficient as an electret additive leading to a 50% increase in charge stability. Filaments with DMDBS exhibited a faster decay. Charging at elevated temperatures resulted in enhanced charge density and stability for both additives. The fiber microstructure was examined by Wide Angle X‐ray Diffraction and Differential Scanning Calorimetry. Rather than reducing the crystal sizes, X‐Ray diffractograms suggest that the crystal size increases with the addition of nucleating agents, while the degree of crystallinity appears to remain unaltered. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2068–2075, 2013 DA - 2013/11/5/ PY - 2013/11/5/ DO - 10.1002/app.39392 VL - 130 IS - 3 SP - 2068-2075 SN - 1097-4628 KW - polyolefins KW - fibers KW - separation techniques KW - blends ER - TY - JOUR TI - Characterization of metabolites of genotoxic 4,4 '-aminoalkoxyazobenzene dyes AU - Freeman, Harold S. AU - Jeong, Euigyung AU - Claxton, Larry D. T2 - DYES AND PIGMENTS AB - Abstract Invariably these days the molecular design of non-genotoxic azo dyes takes into consideration the potential genotoxicity of aromatic amines arising from reductive cleavage of the azo bonds (–N N–), with those dyes producing carcinogenic amines no longer suitable for commerce. Much less is known about structural factors leading to genotoxic azo dyes having their –N N– bonds intact. This point came to the forefront when it was determined that hydrophobic 4,4′-aminoalkoxyazobenzene dyes such as 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N , N -bis(2-hydroxyethyl)aniline are mutagenic but their reductive-cleavage products are not. Consequently, a study that was undertaken to unveil the basis for the mutagenic activity of such dyes. The initial study involved the synthesis and evaluation of the mutagenicity of a group of substituted 4,4′-diaminoalkoxyazobenzene dyes, to test our hypothesis which stated that the mutagenicity of 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N , N -bis(2-hydroxyethyl)aniline arises from the metabolic cleavage of N -hydroxyethyl groups in the parent dye, leading ultimately to 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)aniline. The key goal of the present work was to provide underpinning for results from mutagenicity testing, by isolating and identifying metabolites from S9 treatments. In this regard, title dyes such as 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N , N -bis(2-hydroxyethyl)aniline were treated with rat or hamster liver S9 in the absence of Salmonella typhimurium and results from TLC and HPLC analysis of product mixtures from S9 treatments indicated that metabolism involved N -dehydroxyethylation to give 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N -(2-hydroxyethyl)-aniline and 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)aniline when rat liver S9 was used and reductive cleavage of the azo bonds to give the corresponding aromatic amines was also observed when hamster liver S9 was used. The analysis of product mixtures further indicated that rat liver S9 metabolism involved deacetylation of O -acetyl groups in the case of 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N , N -bis(2-acetoxyethyl)aniline. DA - 2013/11// PY - 2013/11// DO - 10.1016/j.dyepig.2013.06.001 VL - 99 IS - 2 SP - 496-501 SN - 0143-7208 KW - Diaminoalkoxyazobenzene dyes KW - Metabolites KW - N-dehydroxyethylation KW - O-deacetylation KW - Reductive cleavage ER - TY - JOUR TI - Cationic cotton, reservations to reality AU - Farrell, M. J. AU - Hauser, P. J. T2 - AATCC Review DA - 2013/// PY - 2013/// VL - 13 IS - 5 SP - 56-63 ER - TY - JOUR TI - Aromatic amines: use in azo dye chemistry AU - Freeman, Harold S. T2 - FRONTIERS IN BIOSCIENCE-LANDMARK AB - This chapter provides an overview of the chemical structures and properties of aromatic amines and their role in the development and utility of azo dyes. Approaches to the design of environmentally benign alternatives to genotoxic primary aromatic amines, as azo dye precursors, are included. DA - 2013/1/1/ PY - 2013/1/1/ DO - 10.2741/4093 VL - 18 SP - 145-164 SN - 1093-9946 KW - Aromatic amines KW - azo dyes KW - diazo coupling KW - light fastness KW - genotoxicity KW - molecular design KW - basicity KW - synthesis KW - Review ER - TY - JOUR TI - Synthesis of Nanoscale Binders through Mini Emulsion Polymerization for Textile Pigment Applications AU - Abdou, L. A. W. AU - El-Molla, M. M. AU - Hakeim, O. A. AU - El-Gammal, M. S. AU - Shamey, Renzo T2 - INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH AB - Different mini emulsion polymerizations were carried out with the combination of different concentration of anionic surfactant such as sodium dodecyl sulfate (SDS) or hydrophobic alkane such as (hexadecane), and/or different monomer ratios. The best comonomers composition that would lead to the best polymer latex properties to obtain nanoscale polymer latexes was studied. The polymer latexes in a size range between 156 and 65 nm by varying the SDS concentrations from 2 to 6 wt % were obtained, and also the particle size of the obtained polymer latexes decreases with the increases of hexadecane (HD) concentrations, and the best result was obtained with 4 wt % of a hexadecane. The best polymer latex properties in terms of particle size and binder softness were found in the best monomer ratio of BA:MMA:MAA (17.5:1.5:1.5) as the solid content was adapted to be 20%. Higher K/S values and improved crocking fastness are obtained with printing pastes containing prepared binder. DA - 2013/2/13/ PY - 2013/2/13/ DO - 10.1021/ie301705u VL - 52 IS - 6 SP - 2195-2200 SN - 0888-5885 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84873680833&partnerID=MN8TOARS ER - TY - JOUR TI - Synthesis and characterization of silver/lithium cobalt oxide (Ag/LiCoO2) nanofibers via sol-gel electrospinning AU - Aykut, Yakup AU - Pourdeyhimi, Behnam AU - Khan, Saad A. T2 - JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS AB - We report on the preparation and characterization of Ag/LiCoO2 nanofibers (NFs) via the sol–gel electrospinning (ES) technique. Ag nanoparticles (NPs) were produced in an aqueous polyvinyl pyrrolidone (PVP) solution by using AgNO3 precursor. A viscous lithium acetate/cobalt acetate/polyvinylalcohol/water (LiAc/(CoAc)2/PVA/water) solution was prepared separately. A Ag NPs/PVP/water solution was prepared and added to this viscous solution and magnetically stirred to obtain the final homogeneous electrospinning solution. After establishing the proper electrospinning conditions, as-spun precursor Ag/LiAc/Co(Ac)2/PVA/PVP NFs were formed and calcined in air at a temperature of 600 °C for 3 h to form well-crystallized porous Ag/LiCoO2 NFs. Various analytical characterization techniques such as UV–vis, SEM, TEM, TGA, XRD, and XPS were performed to analyze Ag NPs, as-spun and calcined NFs. It was established that Ag NPs in the precursor Ag/LiAc/Co(Ac)2/PVA/PVP NFs are highly self-aligned as a result of the behavior of Ag in the electric field of the electrospinning setup and the interaction of Ag ions with Li and Co ions in the NF. Ag/LiCoO2 NFs exhibit a nanoporous structure compared with un-doped LiCoO2 NFs because the atomic radius of Ag is larger than the radius of Co and Li ion; thus, no substitution between Ag and Li or Ag and Co atoms occurs, and Ag NPs are located at the interlayer of LiCoO2 while some are left in the fiber. DA - 2013/11// PY - 2013/11// DO - 10.1016/j.jpcs.2013.05.021 VL - 74 IS - 11 SP - 1538-1545 SN - 1879-2553 KW - Nanostructures KW - Sol-gel growth KW - Crystal structure KW - Microstructure ER - TY - JOUR TI - Si/C composite nanofibers with stable electric conductive network for use as durable lithium-ion battery anode AU - Fu, Kun AU - Xue, Leigang AU - Yildiz, Ozkan AU - Li, Shuli AU - Lee, Hun AU - Li, Ying AU - Xu, Guanjie AU - Zhou, Lan AU - Bradford, Philip D. AU - Zhang, Xiangwu AU - al., T2 - NANO ENERGY AB - High-energy anode materials have attracted significant attention because of their potential applications in large-scale energy storage devices. However, they often suffer from rapid capacity fading due to the pulverization of the electrode and the breakdown of electric conductive network caused by the large volume changes of active material upon repeated lithium insertion and extraction. In this work, a new electrode composed of Si/C composite nanofibers was prepared, aiming at the improvement of cycling performance of Si anodes through the establishment of a stable electric conductive network for Si during cycling. By electrospinning, a three-dimensional network of carbon nanofibers, which possesses good elasticity to maintain the structure integrity and stable electric conductive network, is formed; by carbon coating, all Si nanoparticles are tightly bonded with carbon fibers to form a stable electric conductive pathway for electrode reactions. The nanofiber structure and the carbon coating on Si, combined with the binder, lead to a stable network structure that can accommodate the huge volume change of Si during the repeated volume expansion and contraction, thus resulting in excellent cycling performance. DA - 2013/5// PY - 2013/5// DO - 10.1016/j.nanoen.2012.11.001 VL - 2 IS - 3 SP - 361-367 SN - 2211-3282 UR - https://publons.com/publon/674385/ KW - Lithium-ion battery anode KW - Volume change KW - Electric conductive network KW - Cycling stability KW - Carbon coating KW - Nanofiber ER - TY - JOUR TI - Mechanochemical strengthening of a synthetic polymer in response to typically destructive shear forces AU - Ramirez, Ashley L. Black AU - Kean, Zachary S. AU - Orlicki, Joshua A. AU - Champhekar, Mangesh AU - Elsakr, Sarah M. AU - Krause, Wendy E. AU - Craig, Stephen L. T2 - NATURE CHEMISTRY AB - High shear stresses are known to trigger destructive bond-scission reactions in polymers. Recent work has shown that the same shear forces can be used to accelerate non-destructive reactions in mechanophores along polymer backbones, and it is demonstrated here that such mechanochemical reactions can be used to strengthen a polymer subjected to otherwise destructive shear forces. Polybutadiene was functionalized with dibromocyclopropane mechanophores, whose mechanical activation generates allylic bromides that are crosslinked in situ by nucleophilic substitution reactions with carboxylates. The crosslinking is activated efficiently by shear forces both in solvated systems and in bulk materials, and the resulting covalent polymer networks possess moduli that are orders-of-magnitude greater than those of the unactivated polymers. These molecular-level responses and their impact on polymer properties have implications for the design of materials that, like biological materials, actively remodel locally as a function of their physical environment. Materials typically break down in response to the repeated mechanical forces that they experience during use. Now, it has been shown that a mechanochemically active polymer can respond to shear forces by forming more bonds than are broken, leading to improved mechanical properties under conditions that would otherwise be destructive. DA - 2013/9// PY - 2013/9// DO - 10.1038/nchem.1720 VL - 5 IS - 9 SP - 757-761 SN - 1755-4349 ER - TY - JOUR TI - Heat treatment of electrospun Polyvinylidene fluoride fibrous membrane separators for rechargeable lithium-ion batteries AU - Liang, Yinzheng AU - Cheng, Sichen AU - Zhao, Jianmeng AU - Zhang, Changhuan AU - Sun, Shiyuan AU - Zhou, Nanting AU - Qiu, Yiping AU - Zhang, Xiangwu T2 - JOURNAL OF POWER SOURCES AB - Polyvinylidene fluoride (PVDF) fibrous membranes for use as lithium-ion battery separators were prepared by electrospinning technique. Heat treatment was introduced to improve the tensile strength and elongation-at-break as well as the tensile modulus of PVDF fibrous membranes, with the best mechanical properties achieved after treatment at 160 °C for 2 h. After heat treatment at 160 °C for 2 h, the ionic conductivity of the liquid electrolyte-soaked PVDF fibrous membranes was 1.35 × 10−3 S cm−1 at room temperature. Moreover, compared with commercial Celgard 2400 separator, heat-treated PVDF fibrous membranes exhibited higher electrochemical stability window and lower interfacial resistance with lithium electrode. In addition, at a 0.2C rate, Li/LiFePO4 cells using heat-treated PVDF fibrous membrane separator showed high charge/discharge capacities and stable cycle performance. DA - 2013/10/15/ PY - 2013/10/15/ DO - 10.1016/j.jpowsour.2013.04.019 VL - 240 SP - 204-211 SN - 0378-7753 UR - https://publons.com/publon/7178365/ KW - Lithium-ion battery KW - Electrospinning KW - PVDF KW - Separator KW - Heat treatment ER - TY - JOUR TI - Developing an ecologically friendly isothermal bath to obtain a new class high-tenacity and high-modulus polypropylene fibers AU - Avci, H. AU - Kotek, R. AU - Yoon, J. T2 - JOURNAL OF MATERIALS SCIENCE DA - 2013/11// PY - 2013/11// DO - 10.1007/s10853-013-7427-1 VL - 48 IS - 22 SP - 7791-7804 SN - 1573-4803 ER - TY - CONF TI - Co3O4/carbon composite nanofibers for use as anode material in advanced lithium-ion batteries AU - Li, S. L. AU - Fu, K. AU - Xue, L. G. AU - Toprakci, O. AU - Li, Y. AU - Zhang, S. AU - Xu, G. J. AU - Lu, Y. AU - Zhang, Xiangwu AB - Co3O4/carbon composite nanofibers were prepared by a combination of electrospinning and carbonization methods using 10 - 30 nm and 30 - 50 nm Co3O4 nanoparticles, respectively, and their potential use as the anode material in rechargeable lithium-ion batteries was investigated. The composite Co3O4/carbon nanofiber electrode containing 30 - 50 nm Co3O4 nanoparticles showed large reversible capacities and good cycleability with charge capacities of 677 and 545 mAh g-1 at the second and twentieth cycles, respectively. In contrast, the composite Co3O4/carbon nanofiber electrode containing 10 - 30 nm Co3O4 nanoparticles showed fast capacity fading during cycling due to severe nanoparticle aggregation. Results suggested that the good electrochemical performance of Co3O4/carbon nanofiber electrode containing 30 - 50 nm Co3O4 nanoparticles was ascribed to the combination of the properties of both Co3O4 nanoparticles (large Li storage capability) and carbon nanofiber matrix (long cycle life), and therefore this electrode material could be potentially used in high-energy rechargeable lithium-ion batteries. C2 - 2013/// C3 - Nanotechnology for sustainable energy DA - 2013/// DO - 10.1021/bk-2013-1140.ch003 VL - 1140 SP - 55–66 UR - https://publons.com/publon/7178343/ ER - TY - JOUR TI - Cellulosic substrates for removal of pollutants from aqueous systems: A review. 3. spilled oil and emulsified organic liquids AU - Hubbe, M. A. AU - Rojas, O. J. AU - Fingas, M. AU - Gupta, B. S. T2 - BioResources AB - Water-insoluble oils, including crude petroleum and a wide variety of refined organic liquids, can cause major problems if spilled or leaked to aqueous environments. Potential environmental damage may be reduced if the spilled oil is promptly and efficiently removed from the water. This article reviews research that sheds light on the use of cellulose-based materials as sorbents to mitigate effects of oil spills. Encouraging results for oil sorption have been reported when using naturally hydrophobic cellulosic fibers such as unprocessed cotton, kapok, or milkweed seed hair. In addition, a wide assortment of cellulosic materials have been shown to be effective sorbents for hydrocarbon oils, especially in the absence of water, and their performance under water-wet conditions can be enhanced by various pretreatments that render them more hydrophobic. More research is needed on environmentally friendly systems to handle oil-contaminated sorbents after their use; promising approaches include their re-use after regeneration, anaerobic digestion, and incineration, among others. Research is also needed to further develop combined response systems in which biosorption is used along with other spill-response measures, including skimming, demulsification, biodegradation, and the use of booms to limit the spreading of oil slicks. DA - 2013/// PY - 2013/// DO - 10.15376/biores.8.2.3038-3097 VL - 8 IS - 2 SP - 3038-1179 ER - TY - JOUR TI - Catalytic graphitization and formation of macroporous-activated carbon nanofibers from salt-induced and H2S-treated polyacrylonitrile AU - Aykut, Yakup AU - Pourdeyhimi, Behnam AU - Khan, Saad A. T2 - JOURNAL OF MATERIALS SCIENCE DA - 2013/11// PY - 2013/11// DO - 10.1007/s10853-013-7463-x VL - 48 IS - 22 SP - 7783-7790 SN - 1573-4803 ER - TY - JOUR TI - Submicron particle filtration in monolith filters - A modeling and experimental study AU - Wu, Mengbai AU - Jasper, Warren J. AU - Kuznetsov, Andrey V. AU - Johnson, Nathan AU - Rasipurarn, Srinivasan C. T2 - JOURNAL OF AEROSOL SCIENCE AB - With over a million micron-sized channels per square centimeter arranged in a regular pattern on a thin film, monolith filters have significant potential for submicron aerosol particle filtration, even though the filtration process with this class of filters has not been well studied. In order to better understand the capture mechanisms and the main factors that affect the capture efficiency, so as to build predictive numerical models and to improve the design of monolith filters, the filtration process in monolith filters was investigated both experimentally and numerically. Using an electrostatic particle classifier (EPC) and a condensation particle counter (CPC), the experimental platform measured the capture efficiency of salt particles with diameters ranging from 50–300 nm on two monolith filter samples. Based on the filtration process and the repeating geometric structure, a single unit model was proposed. The drag force, electrostatic force, and Brownian motion are considered as the major forces affecting particle motion. Published theories underestimated the capture efficiency compared to the experimental results. The Brownian motion model and the capture criterion were then empirically modified to gain better agreement with the experiment. DA - 2013/3// PY - 2013/3// DO - 10.1016/j.jaerosci.2012.09.002 VL - 57 SP - 96-113 SN - 1879-1964 KW - Monolith filter KW - Submicron particles KW - Aerosol filtration KW - Slip flow KW - Quality factor ER - TY - JOUR TI - Plasma Induced Graft Polymerization of C6 Fluorocarbons on Cotton Fabrics for Sustainable Finishing Applications AU - Ramamoorthy, Amsarani AU - El-Shafei, Ahmed AU - Hauser, Peter T2 - PLASMA PROCESSES AND POLYMERS AB - Abstract The main objective of this research is to achieve atmospheric plasma induced graft polymerization of non‐C8 fluorocarbons onto cotton fabrics to achieve a durable nanolayer fluorocarbon coating that is water, alcohol, and oil repellent through home launderings. The influence of process parameters on the performance of polyfluorocarbon was studied using water contact angle measurements, water/alcohol, and oil repellency tests, X‐ray photoelectron spectroscopy, and scanning electron microscopy. A design of experiments for different processing conditions was used. Plasma assisted‐graft polymerization of fluorocarbon in presence of the crosslinker di(ethyleneglycol) diacrylate (10:1 molar ratio of monomer/crosslinker) resulted in a polyfluorocarbon nanolayer on cotton, which was hydrophobic and durable to five home launderings. magnified image DA - 2013/5// PY - 2013/5// DO - 10.1002/ppap.201200111 VL - 10 IS - 5 SP - 430-443 SN - 1612-8869 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84877275449&partnerID=MN8TOARS KW - atmospheric pressure plasma graft polymerization KW - C6 fluorocarbon KW - crosslinker KW - downstream mode KW - durable water repellent cotton finish ER - TY - JOUR TI - Multifunctional and Durable Nanofiber-Fabric-Layered Composite for Protective Application AU - Shi, Quan AU - Vitchuli, Narendiran AU - Nowak, Joshua AU - Jiang, Shan AU - Caldwell, Jane M. AU - Breidt, Frederick AU - Bourham, Mohamed AU - Zhang, Xiangwu AU - McCord, Marian T2 - JOURNAL OF APPLIED POLYMER SCIENCE AB - A multifunctional and durable nanofiber-fabric-layered composite (NFLC) material was prepared by depositing electrospun Ag/PAN hybrid nanofibers onto a Nylon/cotton 50: 50 fabric substrate. The NFLCs showed excellent aerosol barrier efficiency and good air/moisture permeability. In addition, they showed excellent antibacterial efficiency by completely inhibiting the growth of both Gram-negative E. coli and Gram-positive S. aureus. The interfacial adhesion between the nanofiber layer and fabric substrate was significantly improved by atmospheric plasma pretreatment of the substrate. The resultant NFLCs showed excellent resistance to peeling, twisting, and flexing forces. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 DA - 2013/4/15/ PY - 2013/4/15/ DO - 10.1002/app.38465 VL - 128 IS - 2 SP - 1219-1226 SN - 1097-4628 UR - https://publons.com/publon/7178347/ KW - nanostructured polymers KW - textiles KW - biomedical applications ER - TY - JOUR TI - Multi-functional military textile: Plasma-induced graft polymerization of a C6 fluorocarbon for repellent treatment on nylon-cotton blend fabric AU - Malshe, Priya AU - Mazloumpour, Maryam AU - El-Shafei, Ahmed AU - Hauser, Peter T2 - SURFACE & COATINGS TECHNOLOGY AB - This paper reports preparation of a dual functional 50/50 nylon/cotton blend fabric (NyCo) with an anti-bacterial bulk and repellent front surface using atmospheric pressure glow discharge plasma. In this report, a C6 fluorocarbon monomer, 2-(perfluorohexyl)ethyl acrylate was graft polymerized using plasma on the front surface of a nylon–cotton fabric which was already grafted with polyDADMAC for anti-bacterial properties. The surface was characterized by Fourier-transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The presence of fluorine on the surface was mapped and confirmed by time-of-flight secondary ion mass spectroscopy (TOF-SIMS). Scanning electron microscopy (SEM) images showed a uniform layer of fluorocarbon polymer on the fiber surface. High water contact angle of 144° was obtained on the surface. The surface also achieved a high American Association of Textile Chemists and Colorists (AATCC) Test Method 193 rating of 8 and AATCC Test Method 118 rating of 5 indicating that the surface could repel a fluid with surface tension as low as 25 dyn/cm. DA - 2013/2/25/ PY - 2013/2/25/ DO - 10.1016/j.surfcoat.2012.11.081 VL - 217 SP - 112-118 SN - 0257-8972 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84873254605&partnerID=MN8TOARS KW - C6 fluorocarbon KW - Fluid repellent KW - Antibacterial KW - Military fabric ER - TY - JOUR TI - Modelling and experimental studies of air permeability of nonuniform nonwoven fibrous porous media AU - Das, Dipayan AU - Ishtiaque, S. M. AU - Rao, S. V. Ajab AU - Pourdeyhimi, Behnam T2 - FIBERS AND POLYMERS DA - 2013/3// PY - 2013/3// DO - 10.1007/s12221-013-0494-8 VL - 14 IS - 3 SP - 494-499 SN - 1875-0052 KW - Nonwoven KW - Air permeability KW - Packing density KW - Nonuniformity KW - Model KW - Experiment ER - TY - JOUR TI - Improving electret properties of PP filaments with barium titanate AU - Kilic, Ali AU - Shim, Eunkyoung AU - Yeom, Bong Yeol AU - Pourdeyhimi, Behnam T2 - JOURNAL OF ELECTROSTATICS AB - Barium titanate (BaTiO3) containing polypropylene (PP) composite filaments were melt spun to modify polymer electrostatic charging characteristics. Sample filaments were charged with a corona instrument and their surface potentials were measured. Initial surface potential as well as potential stability was monitored through an accelerated decay procedure. It was found that both BaTiO3 concentration and charging temperature influence the charging characteristics of the fibers. When BaTiO3/PP composite filaments were charged at 130 °C, significant enhancements were observed when compared to samples charged at room temperature. The distribution of BaTiO3 particles within the filaments and changes in the crystal structure were also examined. DA - 2013/2// PY - 2013/2// DO - 10.1016/j.elstat.2012.11.005 VL - 71 IS - 1 SP - 41-47 SN - 0304-3886 KW - Polypropylene KW - Barium titanate KW - Electret filters ER - TY - JOUR TI - Enhanced Rate Capability by Employing Carbon Nanotube-Loaded Electrospun Si/C Composite Nanofibers As Binder-Free Anodes AU - Li, Ying AU - Xu, Guanjie AU - Xue, Leigang AU - Zhang, Shu AU - Yao, Yingfang AU - Lu, Yao AU - Toprakci, Ozan AU - Zhang, Xiangwu T2 - JOURNAL OF THE ELECTROCHEMICAL SOCIETY AB - Si/C and Si/carbon nanotube (CNT)/C composite nanofibers were prepared by electrospinning and carbonization. The carbon nanofiber matrix can accommodate the volume change of Si nanoparticles and provide continuous pathways for efficient charge transport along the fiber axis. CNTs can improve the electronic conductivity and electrochemical performance of the composite nanofiber anodes. Results showed that many different types of connections between CNTs, Si nanoparticles and carbon matrix were formed. At a high current density of 300 mA g−1, after 30 cycles, the capacity of Si/CNT/C composite nanofiber anode was 44.3% higher than the anode without CNT and the C-rate performance of Si/CNT/C composite nanofiber anode was also superior to that of Si/C anode. It is, therefore, demonstrated that Si/CNT/C nanofibers are promising anode material with large capacities, good cycling stability, and good rate capability. DA - 2013/// PY - 2013/// DO - 10.1149/2.031304jes VL - 160 IS - 3 SP - A528-A534 SN - 1945-7111 UR - https://publons.com/publon/674380/ ER - TY - JOUR TI - Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture AU - Vacchi, Francine Inforcato AU - Albuquerque, Anjaina Fernandes AU - Vendemiatti, Josiane Aparecida AU - Morales, Daniel Alexandre AU - Ormond, Alexandra B. AU - Freeman, Harold S. AU - Zocolo, Guilherme Juliao AU - Boldrin Zanoni, Maria Valnice AU - Umbuzeiro, Gisela T2 - SCIENCE OF THE TOTAL ENVIRONMENT AB - Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC-ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. DA - 2013/1/1/ PY - 2013/1/1/ DO - 10.1016/j.scitotenv.2012.10.019 VL - 442 SP - 302-309 SN - 1879-1026 KW - CI Disperse Red 1 KW - Chlorination KW - Commercial dye mixture KW - LC-MS KW - Daphnia KW - Salmonella/microsome assay ER - TY - JOUR TI - Carbon-Coated Si Nanoparticles Dispersed in Carbon Nanotube Networks As Anode Material for Lithium-Ion Batteries AU - Xue, Leigang AU - Xu, Guanjie AU - Li, Ying AU - Li, Shuli AU - Fu, Kun AU - Shi, Quan AU - Zhang, Xiangwu T2 - ACS APPLIED MATERIALS & INTERFACES AB - Si has the highest theoretical capacity among all known anode materials, but it suffers from the dramatic volume change upon repeated lithiation and delithiation processes. To overcome the severe volume changes, Si nanoparticles were first coated with a polymer-driven carbon layer, and then dispersed in a CNT network. In this unique structure, the carbon layer can improve electric conductivity and buffer the severe volume change, whereas the tangled CNT network is expected to provide additional mechanical strength to maintain the integrity of electrodes, stabilize the electric conductive network for active Si, and eventually lead to better cycling performance. Electrochemical test result indicates the carbon-coated Si nanoparticles dispersed in CNT networks show capacity retention of 70% after 40 cycles, which is much better than the carbon-coated Si nanoparticles without CNTs. DA - 2013/1/9/ PY - 2013/1/9/ DO - 10.1021/am3027597 VL - 5 IS - 1 SP - 21-25 SN - 1944-8252 UR - https://publons.com/publon/1792840/ KW - lithium-ion battery KW - si-based anode KW - cycling stability KW - carbon coating KW - CNT networks ER - TY - JOUR TI - Acoustical absorptive properties of spunbonded nonwovens made from islands-in-the-sea bicomponent filaments AU - Suvari, Fatih AU - Ulcay, Yusuf AU - Maze, Benoit AU - Pourdeyhimi, Behnam T2 - JOURNAL OF THE TEXTILE INSTITUTE AB - Abstract In this paper, we report on the acoustical absorptive behavior of spunbonded nonwovens that contain bicomponent islands-in-the-sea filaments. Nylon 6 (PA6) and polyethylene were used as the islands and the sea polymers, respectively. Spunbonded webs made with islands-in-the-sea bicomponent filaments with island counts of 1, 7, 19, 37, and 108 were produced at the Nonwovens Institute’s pilot facilities at NC State University. The filaments were fibrillated by hydroentangling, where high-speed water jets were used to fibrillate the fiber and ‘free’ the islands. The influence of the number of islands on acoustical absorptive behavior of the spunbonded nonwovens was investigated. A comparison of acoustical absorptive properties of multi-layer islands-in-the-sea nonwoven and high loft nonwoven was also performed to evaluate the potential use of spunbonded nonwovens made from islands-in-the-sea bicomponent filaments in place of bulky fibrous sound absorbers. Results have shown that multi-layer 108 nonwoven islands were better acoustic absorbers at nearly half of the frequency range. Spunbonded nonwovens made from islands-in-the-sea bicomponent filaments can be a good alternative in applications where there is desire to replace bulky fibrous sound absorbers. Keywords: spunbondingsound absorptionbicomponent filamentsislands-in-the-sea Acknowledgements This work was supported by a grant from the Nonwovens Institute. Their support is gratefully acknowledged. The first author would like to thank TUBITAK for individual support. DA - 2013/4/1/ PY - 2013/4/1/ DO - 10.1080/00405000.2012.740330 VL - 104 IS - 4 SP - 438-445 SN - 1754-2340 KW - spunbonding KW - sound absorption KW - bicomponent filaments KW - islands-in-the-sea ER - TY - JOUR TI - Synthesis of Mixed Ceramic MgxZn1-xO Nanofibers via Mg2+ Doping Using Sol-Gel Electrospinning AU - Aykut, Yakup AU - Parsons, Gregory N. AU - Pourdeyhimi, Behnam AU - Khan, Saad A. T2 - LANGMUIR AB - We report on the synthesis of tuned energy band gap MgxZn1–xO nanofibers (NFs) with different Mg2+ content via the sol–gel electrospinning (ES) technique wherein the addition of the doping material affects not only the morphologies of as-spun ZnAc/PVA and MgAc/ZnAc/PVA nanofibers but also the crystal microstructure and optical properties of calcined ZnO and MgxZn1–xO nanofibers. Following an appropriate aqueous solution preparation of magnesium acetate (MgAc) and zinc acetate (ZnAc) with poly(vinyl alcohol) (PVA), electrospinning is performed and then as-spun nanofibers are calcined in an air atmosphere at 600 °C for 3 h. As-spun and calcined nanofiber diameters and morphologies are evaluated with scanning (SEM) and transmission (TEM) electron microscopies, whereas crystalline microstructural interpretations of ZnO and MgxZn1–xO are conducted with wide-angle X-ray diffraction spectra (XRD). Surface chemical composition and elemental evaluation of calcined nanofibers are examined with X-ray photoelectron spectroscopy (XPS), and optical properties and crystal defect analyses of the calcined nanofibers are conducted with photoluminescence spectra (PL). We observe a sharp reduction in fiber diameter upon calcination as a result of the removal of organic species from the fibers and conversion of ceramic precursors into ceramic nanofibers, and the appearance of a range of fiber morphologies from “bead in a string” to “sesame seed” coverage depending on fiber composition. Because Zn2+ and Mg2+ have similar ionicity and atomic radii, some Zn2+ atoms are replaced by Mg2+ atoms in the crystals, leading to a change in the properties of crystal lattices. The band gap energy of the calcined fibers increases significantly with addition of Mg2+ along with an increase in the ultraviolet (UV) photoluminescence emission of the fibers. DA - 2013/3/26/ PY - 2013/3/26/ DO - 10.1021/la400281c VL - 29 IS - 12 SP - 4159-4166 SN - 0743-7463 ER - TY - JOUR TI - Synthesis and Pharmacological Screening of Novel meso-Substituted Porphyrin Analogs AU - Fadda, Ahmed A. AU - El-Mekawy, Rasha E. AU - El-Shafei, Ahmed I. AU - Freeman, Harold T2 - ARCHIV DER PHARMAZIE AB - Abstract A novel series of meso tetrakis[aryl]‐21 H ,23 H ‐porphyrin derivatives 2a – j was synthesized from the condensation of aldehyde derivatives 1a – j with pyrrole in the presence of p ‐toluenesulfonic acid. The synthesized porphyrins were considered as a model to study the free radical‐induced damage of biological membranes and the protective effects of these porphyrins. It was found that these compounds effectively inhibit the free radical‐induced oxidative hemolysis of red blood cells. Compounds 2c and 2d which bear a sulfur atom, a nitro group, and a chlorine atom exhibited markedly higher antihemolysis activity than the other analogous. Compounds 2a , 2c , 2d , and 2j showed the highest protection activity against DNA damage induced by the bleomycin–iron complex. Compounds 2d , 2f , 2i , and 2j were proved to exhibit antioxidative activity. DA - 2013/1// PY - 2013/1// DO - 10.1002/ardp.201200313 VL - 346 IS - 1 SP - 53-61 SN - 0365-6233 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84872271916&partnerID=MN8TOARS KW - Antioxidant KW - Cytotoxic and hemolysis activities KW - DNA damage KW - Porphyrins KW - UV spectra ER - TY - JOUR TI - Structure-property relationship of different electron donors: novel organic sensitizers based on fused dithienothiophene pi-conjugated linker for high efficiency dye-sensitized solar cells AU - Akhtaruzzaman, Md. AU - Menggenbateer AU - Islam, Ashraful AU - El-Shafei, Ahmed AU - Asao, Naoki AU - Jin, Tienan AU - Han, Liyuan AU - Alamry, Khalid A. AU - Kosa, Samia A. AU - Asiri, Abdullah Mohamed AU - Yamamoto, Yoshinori T2 - TETRAHEDRON AB - Three novel organic dyes, coded Ba-01–03, based on D–π–A building blocks were synthesized and characterized for dye-sensitized solar cells (DSCs) to study the influence of different electron donors on photocurrent and photovoltage. The electron donor of Ba-01 was based on N-methoxyphenylcarbazole and the electron donors for Ba-02 and Ba-03 were based on different indoline analogs. The photovoltaic performance of these sensitizers was characterized using incident-photon-to-current conversion efficiency (IPCE), photovoltage measurements, and total solar-to-electric conversion efficiency (η). It was shown that photovoltage of indoline donor based dye Ba-03 showed the highest efficiency of 6.38% compared to carbazole donor based dye of Ba-01. DFT calculations were proven to be an effective tool in the prediction of the vertical electronic excitation, charge separation, and photovoltage as it effectively predicted the delocalization and coefficient size of the HOMO and LUMO for Ba-01–03. DA - 2013/4/22/ PY - 2013/4/22/ DO - 10.1016/j.tet.2013.02.058 VL - 69 IS - 16 SP - 3444-3450 SN - 0040-4020 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84875232103&partnerID=MN8TOARS KW - Dye-sensitized solar cells KW - Dithienothiophene KW - Organic dye KW - Photovoltaic performance KW - IPCE (incident-photon-to-current conversion efficiency) ER - TY - JOUR TI - Prediction of angular and mass distribution in meltblown polymer lay-down AU - Sinha-Ray, S. AU - Yarin, A. L. AU - Pourdeyhimi, B. T2 - POLYMER AB - Predictions of the properties of meltblown polymer nonwovens require knowledge of the angular fiber distribution in lay-down, as well as the deposited mass distribution. In the present work these two important characteristics are predicted using our previously developed model describing multiple three-dimensional viscoelastic polymer jets in meltblowing and their deposition onto a moving screen normal to the blowing direction. The results are important for predictions of strength of meltblown nonwovens. DA - 2013/1/24/ PY - 2013/1/24/ DO - 10.1016/j.polymer.2012.11.061 VL - 54 IS - 2 SP - 860-872 SN - 0032-3861 KW - Angular and mass distribution KW - Forming microfibers KW - Polymer lay-down ER - TY - JOUR TI - Modeling of Flow Through a Sandwiched Monolith Filter AU - Gangadharan, S. AU - Sanghavi, R. S. AU - Kuznetsov, A. V. AU - Jasper, W. J. T2 - PARTICULATE SCIENCE AND TECHNOLOGY AB - The flow field and filtration efficiency was modeled and analyzed for a novel monolith filter, comprised of a series of layers of microchannels. In our simulations, we considered two scenarios: the fluid flowing tangentially across the filter face (cross flow) and fluid flowing normal to the filter face (normal flow). The aim of this article is to study the effect of having two or more layers of filters in series on particle capture efficiency. This will help in understanding the mechanisms of particle capture and provide inputs for studying particle segregation or selective filtration using monolith filters. The influences of particle size, number of filter layers and pressure drop on particle capture efficiency were also investigated. DA - 2013/5/1/ PY - 2013/5/1/ DO - 10.1080/02726351.2012.715614 VL - 31 IS - 3 SP - 226-233 SN - 0272-6351 KW - Multi-stage filtration KW - numerical modeling KW - particle size segregation ER - TY - JOUR TI - Electrospun nanofiber-coated separator membranes for lithium-ion rechargeable batteries AU - Lee, Hun AU - Alcoutlabi, Mataz AU - Watson, Jill V. AU - Zhang, Xiangwu T2 - JOURNAL OF APPLIED POLYMER SCIENCE AB - Abstract Nanofiber‐coated composite membranes were prepared by electrospinning polyvinylidene fluoride‐ co ‐chlorotrifluoroethylene (PVDF‐ co ‐CTFE) and PVDF‐ co ‐CTFE/polyvinylidene fluoride‐ co ‐hexafluoropropylene (PVDF‐ co ‐HFP) onto six different Celgard® microporous battery separator membranes. Application of a PVDF‐based copolymer nanofiber coating onto the surface of the battery separator membrane provides a method for improving the electrolyte absorption of the separator and the separator‐electrode adhesion. Peel tests showed that both PVDF‐ co ‐CTFE and PVDF‐ co ‐CTFE/PVDF‐ co ‐HFP nanofiber coatings have comparable adhesion to the membrane substrates. Electrolyte uptake capacity was investigated by soaking the nanofiber‐coated membranes in a liquid electrolyte solution. PVDF‐ co ‐CTFE and PVDF‐ co ‐CTFE/PVDF‐ co ‐HFP nanofiber‐coated membranes exhibited higher electrolyte uptake capacities than uncoated membranes. It was also found that PVDF‐ co ‐CTFE nanofiber‐coated membranes have higher electrolyte uptakes than PVDF‐ co ‐CTFE/PVDF‐ co ‐HFP nanofiber‐coated membranes due to the smaller diameters of PVDF‐ co ‐CTFE nanofibers and higher polarity of PVDF‐ co ‐CTFE. The separator–electrode adhesion properties were also investigated. Results showed PVDF‐ co ‐CTFE and PVDF‐ co ‐CTFE/PVDF‐ co ‐HFP nanofiber coatings improved the adhesion of all six membrane substrates to the electrode. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 DA - 2013/8/15/ PY - 2013/8/15/ DO - 10.1002/app.38894 VL - 129 IS - 4 SP - 1939-1951 SN - 1097-4628 UR - https://publons.com/publon/7178362/ KW - batteries and fuel cells KW - blends KW - coatings ER - TY - JOUR TI - Effect of fabric substrate and coating material on the quality of conductive printing AU - Suh, Minyoung AU - Carroll, Katherine E. AU - Grant, Edward AU - Oxenham, William T2 - JOURNAL OF THE TEXTILE INSTITUTE AB - This paper reports an investigation into the effect of fabric substrates and coating materials on the electrical and mechanical performance of printed antennas. Inductively coupled antennas were printed on fabrics using silver ink. To assure printability and protection, a printing structure was configured, consisting of surface coating, conductive printing, and protective coating. In order to simulate a realistic situation, three fabric substrates (denim, broadcloth, and single jersey) were selected from woven and knit fabrics for everyday wear. Three coating materials (acrylic, polyurethane, and silicone) were chosen from conventional conformal coating materials for printed circuit boards. Experimental results verified that fabric substrates can be selected to fit specific end-use application since it is shown that antenna performance was not significantly affected. Silicone coating is suggested to support antenna performance since this gave the least impairment in the fabrics as mechanical performance. DA - 2013/2/1/ PY - 2013/2/1/ DO - 10.1080/00405000.2012.714107 VL - 104 IS - 2 SP - 213-222 SN - 0040-5000 KW - smart textiles KW - conductive printing KW - protective coating KW - printed antenna KW - inductive coupling ER - TY - JOUR TI - Direct Analysis of Textile Fabrics and Dyes Using Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry AU - Cochran, Kristin H. AU - Barry, Jeremy A. AU - Muddiman, David C. AU - Hinks, David T2 - ANALYTICAL CHEMISTRY AB - The forensic analysis of textile fibers uses a variety of techniques from microscopy to spectroscopy. One such technique that is often used to identify the dye(s) within the fiber is mass spectrometry (MS). In the traditional MS method, the dye must be extracted from the fabric and the dye components are separated by chromatography prior to mass spectrometric analysis. Direct analysis of the dye from the fabric allows the omission of the lengthy sample preparation involved in extraction, thereby significantly reducing the overall analysis time. Herein, a direct analysis of dyed textile fabric was performed using the infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) source for MS. In MALDESI, an IR laser with wavelength tuned to 2.94 μm is used to desorb the dye from the fabric sample with the aid of water as the matrix. The desorbed dye molecules are then postionized by electrospray ionization (ESI). A variety of dye classes were analyzed from various fabrics with little to no sample preparation allowing for the identification of the dye mass and in some cases the fiber polymer. Those dyes that were not detected using MALDESI were also not observed by direct infusion ESI of the dye standard. DA - 2013/1/15/ PY - 2013/1/15/ DO - 10.1021/ac302519n VL - 85 IS - 2 SP - 831-836 SN - 0003-2700 ER - TY - JOUR TI - Characterizing polymer macrostructures by identifying and locating microstructures along their chains with the kerr effect AU - Hardrict, S. N. AU - Gurarslan, R. AU - Galvin, C. J. AU - Gracz, H. AU - Roy, D. AU - Sumerlin, B. S. AU - Genzer, J. AU - Tonelli, A. E. T2 - JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS AB - Abstract In this brief report, we demonstrate that Kerr effect measurements, which determine the excess birefringence contributed by polymer solutes in dilute solutions observed under a strong electric field, are highly sensitive to and capable of determining their microstructures, as well as their locations along the macromolecular backbone. Specifically, using atactic triblock copolymers with the same overall composition of styrene (S) and p ‐bromostyrene ( p BrS) units, but with two different block arrangements, that is, p BrS 90 ‐ b ‐S 120 ‐ b ‐ p BrS 90 (I) and S 60 ‐ b ‐ p BrS 180 ‐ b ‐S 60 (II), which are indistinguishable by NMR, we detected a dramatic difference in their molar Kerr constants ( m K ), in agreement with those previously estimated. Although similar in magnitude, their Kerr constants differ in sign, with m K (II) positive and m K (I) negative. In addition, S/ p BrS random and gradient copolymers synthesized by reversible addition‐fragmentation chain‐transfer (RAFT) polymerization exhibit a heretofore unexpected enhanced enchainment of racemic ( r ) p BrS‐ p BrS diads. Comparison of their observed and calculated m K s suggests that the gradient S/ p BrS copolymers possess an unanticipated additional gradient in stereosequence that parallels their comonomer gradient, that is, as the concentration of p Brs units decreases from one end of the copolymer chain to the other, so does the content of r diads. This conclusion could only be reached by comparison of observed and calculated Kerr effects, which access the global properties of macromolecules, and not NMR, which is only sensitive to local polymer structural environments, but not to their locations on the copolymer chains. Molar Kerr constants are characteristic of entire polymer chains and are highly sensitive to their constituent microstructures and their distribution along the chain. They may be used to both identify constituent microstructures and locate them along the polymer chain, thereby enabling, for the first time, characterization of their complete macrostructures. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 DA - 2013/5/1/ PY - 2013/5/1/ DO - 10.1002/polb.23248 VL - 51 IS - 9 SP - 735-741 SN - 0887-6266 KW - microstructure KW - solution properties KW - structure-property relations KW - thin films ER - TY - JOUR TI - Wind blade joints based on non-crimp 3D orthogonal woven Pi shaped preforms AU - Sharp, Keith AU - Bogdanovich, Alexander AU - Boyle, Ryan AU - Brown, Jesse AU - Mungalov, Dmitri T2 - COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING AB - Current industrial designs for joining composite wind blade elements allow unstable crack propagation in the thick adhesive layer within the joint. In this work, a novel integral 3D woven Pi-joint element is developed and implemented in an I-beam joint construction that corresponds to a wind blade’s shear web and spar cap. In a series of iterative design–analysis–fabrication–testing cycles, 2.9 m long I-beams that used the current practice joint and the novel proposed joint were designed, studied theoretically with the use of a 3D Mosaic analysis tool, then manufactured and loaded to failure in a cantilever flexure loading set up. Experimental data showed significant advantage in the load-bearing capacity of the joint structure with the use of novel Pi-joint element. Excellent agreement was observed between the theoretical predictions and experimental data. DA - 2013/6// PY - 2013/6// DO - 10.1016/j.compositesa.2013.01.012 VL - 49 SP - 9-17 SN - 1359-835X KW - Polymer-matrix composites (PMCs) KW - 3-Dimensional reinforcement KW - Joints/joining KW - Weaving ER - TY - JOUR TI - Ultrastretchable Fibers with Metallic Conductivity Using a Liquid Metal Alloy Core AU - Zhu, Shu AU - So, Ju-Hee AU - Mays, Robin AU - Desai, Sharvil AU - Barnes, William R. AU - Pourdeyhimi, Behnam AU - Dickey, Michael D. T2 - ADVANCED FUNCTIONAL MATERIALS AB - Abstract The fabrication and characterization of fibers that are ultrastretchable and have metallic electrical conductivity are described. The fibers consist of a liquid metal alloy, eutectic gallium indium (EGaIn), injected into the core of stretchable hollow fibers composed of a triblock copolymer, poly[styrene‐ b ‐(ethylene‐ co ‐butylene)‐ b ‐styrene] (SEBS) resin. The hollow fibers are easy to mass‐produce with controlled size using commercially available melt processing methods. The fibers are similar to conventional metallic wires, but can be stretched orders of magnitude further while retaining electrical conductivity. Mechanical measurements with and without the liquid metal inside the fibers show the liquid core has a negligible impact on the mechanical properties of the fibers, which is in contrast to most conductive composite fibers. The fibers also maintain the same tactile properties with and without the metal. Electrical measurements show that the fibers increase resistance as the fiber elongates and the cross sectional area narrows. Fibers with larger diameters change from a triangular to a more circular cross‐section during stretching, which has the appeal of lowering the resistance below that predicted by theory. To demonstrate their utility, the ultrastretchable fibers are used as stretchable wires for earphones and for a battery charger and perform as well as their conventional parts. DA - 2013/5/13/ PY - 2013/5/13/ DO - 10.1002/adfm.201202405 VL - 23 IS - 18 SP - 2308-2314 SN - 1616-3028 KW - stretchable electronics KW - eutectic gallium indium KW - conductive fibers ER - TY - JOUR TI - Structures and properties of SnO2 nanofibers derived from two different polymer intermediates AU - Xia, Xin AU - Li, Shuli AU - Wang, Xin AU - Liu, Junxiong AU - Wei, Qufu AU - Zhang, Xiangwu T2 - JOURNAL OF MATERIALS SCIENCE DA - 2013/5// PY - 2013/5// DO - 10.1007/s10853-012-7122-7 VL - 48 IS - 9 SP - 3378-3385 SN - 1573-4803 UR - https://publons.com/publon/7178341/ ER - TY - JOUR TI - N-(hydroxymethyl) acrylamide as a multifunctional finish to cotton and a tether for grafting methacrylamide for biocidal coatings AU - Yildiz, Ozkan AU - Cerkez, Idris AU - Kocer, Hasan B. AU - Worley, S. D. AU - Broughton, R. M. AU - Huang, T. S. T2 - JOURNAL OF APPLIED POLYMER SCIENCE AB - Abstract N ‐(hydroxymethyl) acrylamide (NMA) was immobilized on cotton surfaces through etherification, and then methacrylamide (MA) was grafted onto the treated surface. The coatings were characterized by ATR‐IR spectroscopy and were rendered biocidal upon exposure to dilute household bleach. The treated fabrics were challenged with Gram‐negative and Gram‐positive bacteria; both NMA and NMA/MA‐treated fabrics inactivated about 8 logs of Escherichia coli O157:H7 and Staphylococcus aureus within only 5 min of contact time. The coatings were also quite stable toward ultraviolet (UVA) light exposure and repeated laundering. Moreover, a substantial improvement in wrinkle recovery angle was obtained for the NMA/MA‐treated fabrics. The new acyclic acrylamide N ‐halamine coating should be less expensive to produce and use than previous cyclic N ‐halamine coatings developed in these laboratories. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 DA - 2013/6/15/ PY - 2013/6/15/ DO - 10.1002/app.38692 VL - 128 IS - 6 SP - 4405-4410 SN - 1097-4628 KW - coatings KW - crosslinking KW - textiles KW - N-halamine KW - antimicrobial ER - TY - JOUR TI - Midblock-sulfonated triblock ionomers derived from a long-chain poly[styrene-b-butadiene-b-styrene] triblock copolymer AU - Vargantwar, Pruthesh H. AU - Brannock, Molly C. AU - Tauer, Klaus AU - Spontak, Richard J. T2 - JOURNAL OF MATERIALS CHEMISTRY A AB - Selective sulfonation of a poly[styrene-b-butadiene-b-styrene] (SBS) triblock copolymer has been performed with a sulfur trioxide–dioxane (SO3–dioxane) complex to generate midblock-sulfonated triblock ionomers possessing varying degrees of sulfonation (DOS). Products of the sulfonation reaction have been characterized by proton nuclear magnetic resonance and Fourier-transform infrared spectroscopies to ensure sulfonation only involves the B midblocks. Due to this targeted sulfonation, the lower glass transition temperature (Tg) disappears completely in all the ionomers examined, indicating that the formation of ionic aggregates restricts the mobility of the B midblocks. Such aggregates hinder microphase separation and promote a diffuse interface, as established by progressive broadening of the upper Tg with increasing DOS. Additional evidence of diffuse interfaces and matrix densification is provided by small-angle X-ray scattering, which reveals a concurrent size reduction in microdomain spacing with increasing DOS. A sulfonation-induced order–order morphological transition from cylinders to lamellae is likewise observed. Due to the retention of microphase-separated glassy microdomains that serve as physical crosslinks, these triblock ionomers are capable of absorbing remarkably high solvent levels and forming highly swollen gel networks in polar media, thereby making them suitable for use in hygiene and healthcare applications, as well as in devices requiring ion transport. DA - 2013/// PY - 2013/// DO - 10.1039/c2ta00022a VL - 1 IS - 10 SP - 3430-3439 SN - 2050-7496 ER - TY - JOUR TI - Improving water solubility of poly(acrylic acid-co-styrene) copolymers by adding styrene sulfonic acid as a termonomer AU - Akyildiz, Halil I. AU - Michielsen, Stephen T2 - JOURNAL OF APPLIED POLYMER SCIENCE AB - Abstract Acrylic acid is often used to make water‐soluble polymers while styrene is often modified to add special functions to polymers. However, when styrene and acrylic acid are copolymerized, the resulting polymer is much less water soluble. To regain water solubility, the effect of styrene sulfonic acid on solubility of poly(acrylic acid‐ co ‐styrene) copolymers was investigated. Even though acrylic acid polymers are known for their water solubility, the presence of styrene units within acrylic acid copolymers reduces the solubility of the copolymer substantially at the natural pH of the solutions. By adding styrene sulfonic acid as a termonomer, polymers that are water soluble at the natural pH of the polymerization could be obtained. The solubility of the polymer after removal of the solvent and by redissolving at different concentrations and pH levels is also reported. Solubility increases at higher pH especially with low styrene concentration in the copolymer. It was found that incorporation of as little as 5 mol % of styrene into poly(acrylic acid) reduced the aqueous solubility to less than 0.5 g dL −1 at pH 7. Upon adding 7 mol % styrene sulfonic acid as a termonomer, the water solubility increased to 5 g dL −1 at pH 7. At higher levels of styrene, more styrene sulfonic acid was needed, especially at low pH. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 DA - 2013/8/15/ PY - 2013/8/15/ DO - 10.1002/app.38933 VL - 129 IS - 4 SP - 2208-2215 SN - 0021-8995 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000319275700064&KeyUID=WOS:000319275700064 KW - stimuli-sensitive polymers KW - copolymers KW - hydrophilic polymers KW - phase behavior KW - polyelectrolytes ER - TY - JOUR TI - Frictional electrification on polymeric flat surfaces AU - Liu, L. AU - Seyam, A. M. AU - Oxenham, W. T2 - Journal of Engineered Fibers and Fabrics DA - 2013/// PY - 2013/// VL - 8 IS - 1 SP - 126-136 ER - TY - JOUR TI - Extraction of natural dyes from Alpinia blepharocalyx K. Schum. for dyeing of silk fabric AU - Wang, Chunxia AU - Xu, Changhai AU - Tian, Anli AU - Fu, Shaohai AU - Wang, Chaoxia T2 - COLORATION TECHNOLOGY AB - Natural dyes were extracted from the leaves and stems of Alpinia blepharocalyx K. Schum. Analysis of the designed experiment revealed that extraction at a plant/water ratio of 1:20 could reach an optimal production of natural dyes when extraction was performed at 80 °C, for 4 h, under 20 min ultrasound, in the presence of 10 g/l sodium hydroxide, and with two extractions. The extracted natural dyes were applied to the dyeing of silk fabrics using different methods, including or excluding a mordant. It was found that mordants had a significant effect on the colour of dyed silk fabrics. The silk fabric dyed with the pre‐mordant method using potassium aluminium sulphate as a mordant showed a bright yellow with a higher colour strength. The optimal dyeing conditions were reached when the extracted natural dyes were pre‐mordanted with 10 g/l potassium aluminium sulphate at pH 6, and for a 20 min dyeing time. DA - 2013/2// PY - 2013/2// DO - 10.1111/j.1478-4408.2012.00407.x VL - 129 IS - 1 SP - 32-38 SN - 1472-3581 ER - TY - JOUR TI - Dye Sensitizers for Photodynamic Therapy AU - Ormond, Alexandra B. AU - Freeman, Harold S. T2 - MATERIALS AB - Photofrin® was first approved in the 1990s as a sensitizer for use in treating cancer via photodynamic therapy (PDT). Since then a wide variety of dye sensitizers have been developed and a few have been approved for PDT treatment of skin and organ cancers and skin diseases such as acne vulgaris. Porphyrinoid derivatives and precursors have been the most successful in producing requisite singlet oxygen, with Photofrin® still remaining the most efficient sensitizer (quantum yield = 0.89) and having broad food and drug administration (FDA) approval for treatment of multiple cancer types. Other porphyrinoid compounds that have received approval from US FDA and regulatory authorities in other countries include benzoporphyrin derivative monoacid ring A (BPD-MA), meta-tetra(hydroxyphenyl)chlorin (m-THPC), N-aspartyl chlorin e6 (NPe6), and precursors to endogenous protoporphyrin IX (PpIX): 1,5-aminolevulinic acid (ALA), methyl aminolevulinate (MAL), hexaminolevulinate (HAL). Although no non-porphyrin sensitizer has been approved for PDT applications, a small number of anthraquinone, phenothiazine, xanthene, cyanine, and curcuminoid sensitizers are under consideration and some are being evaluated in clinical trials. This review focuses on the nature of PDT, dye sensitizers that have been approved for use in PDT, and compounds that have entered or completed clinical trials as PDT sensitizers. DA - 2013/3// PY - 2013/3// DO - 10.3390/ma6030817 VL - 6 IS - 3 SP - 817-840 SN - 1996-1944 KW - photodynamic therapy KW - photosensitizers KW - porphyrins KW - clinical trials KW - target organs ER - TY - JOUR TI - Conferring flame retardancy on cotton using novel halogen-free flame retardant bifunctional monomers: synthesis, characterizations and applications AU - Cheema, Hammad A. AU - El-Shafei, Ahmed AU - Hauser, Peter J. T2 - Carbohydrate Polymers AB - Two novel halogen-free phosphorous-nitrogen flame retardant bifunctional monomers were synthesized and characterized using attenuated total reflectance/Fourier transform-infrared (ATR/FT-IR) and electrospray ionization mass spectrometry ((+)ESI-MS). The monomers were applied separately and graft polymerized on cotton in the presence of the thermal initiator K(2)S(2)O(8). The performance of each monomer was evaluated using thermal gravimetric analysis (TGA), grafting efficiency, and vertical flame test. It was shown that the performance of N,N-dimethyl di(acryloyloxyethyl)phosphoramide (DMDAEP) (monomer 2) as flame retardant outperformed that of ethyl di(acryloyloxyethyl)phosphorodiamidate (EDAEP) (monomer 1). The superior performance of DMDAEP was attributed to the presence of more nitrogen atoms compared to EDAEP. The increased nitrogen content in DMDAEP increased the synergistic effect of the P-N system. Cotton treated using padding methods showed more promising results than cotton treated by exhaust methods. DA - 2013/1// PY - 2013/1// DO - 10.1016/j.carbpol.2012.09.081 VL - 92 IS - 1 SP - 885-893 J2 - Carbohydrate Polymers LA - en OP - SN - 0144-8617 UR - http://dx.doi.org/10.1016/j.carbpol.2012.09.081 DB - Crossref KW - Cotton KW - Flame retardants KW - Halogen-free KW - Phosphorus-nitrogen synergism KW - Monomers KW - Bifunctional ER - TY - JOUR TI - Characterisation and numerical modelling of complex deformation behaviour in thermally bonded nonwovens AU - Farukh, Farukh AU - Demirci, Emrah AU - Sabuncuoglu, Baris AU - Acar, Memis AU - Pourdeyhimi, Behnam AU - Silberschmidt, Vadim V. T2 - COMPUTATIONAL MATERIALS SCIENCE AB - A complex time-dependent deformation and damage behaviour in polymer-based nonwovens are analysed under conditions of multi-stage uniaxial loading. Elastic–plastic and viscous properties of a polypropylene-based fabric are obtained by series of tensile, creep and relaxation tests performed on single fibres extracted from the studied fabric. These properties are implemented in a finite-element (FE) model of nonwoven with direct introduction of fibres according to their actual orientation distribution in order to simulate the rate-dependent deformation up to the onset of damage in thermally bonded nonwovens. The predictions of FE simulations are compared with the experimental data of multi-stage deformation tensile tests and a good agreement is obtained including the mechanisms of deformation. Due to direct modelling of fibres based on their actual orientation distribution and implementation of viscous properties, the model could be extended to other types of polymer-based random fibrous networks. DA - 2013/4// PY - 2013/4// DO - 10.1016/j.commatsci.2013.01.007 VL - 71 SP - 165-171 SN - 1879-0801 KW - Nonwoven KW - Polypropylene KW - Viscous KW - Finite element KW - Damage ER - TY - JOUR TI - Atmospheric plasma application to improve adhesion of electrospun nanofibers onto protective fabric AU - Vitchuli, Narendiran AU - Shi, Quan AU - Nowak, Joshua AU - Nawalakhe, Rupesh AU - Sieber, Michael AU - Bourham, Mohamed AU - Zhang, Xiangwu AU - McCord, Marian T2 - JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY AB - Nylon 6 electrospun nanofibers were deposited on plasma-pretreated woven fabric substrates with the objective of improving adhesion between them. The prepared samples were evaluated for adhesion strength and durability of nanofiber mats by carrying out peel strength, flex resistance, and abrasion resistance tests. The test results showed significant improvement in the adhesion of nanofiber mats on woven fabric substrates due to atmospheric plasma pretreatment. The samples also exhibited good flex and abrasion resistance characteristics. X-ray photoelectron spectroscopy and water contact angle analyses indicate that plasma pretreatment introduces radicals, increases the oxygen content on the substrate surface, and leads to formation of active chemical sites that may be responsible for enhanced cross-linking between the substrate fabric and the electrospun nanofibers, which in turn increases the adhesion properties. The work demonstrates that the plasma treatment of the substrate fabric prior to deposition of electrospun nanofiber mats is a promising method to prepare durable functional materials. DA - 2013/4/1/ PY - 2013/4/1/ DO - 10.1080/01694243.2012.727164 VL - 27 IS - 8 SP - 924-938 SN - 0169-4243 UR - https://publons.com/publon/7178346/ KW - adhesion KW - atmospheric pressure plasma KW - cross-linking KW - dielectric barrier discharge KW - electrospinning KW - water contact angle ER - TY - JOUR TI - Antibacterial activity of photocatalytic electrospun titania nanofiber mats and solution-blown soy protein nanofiber mats decorated with silver nanoparticles AU - Zhang, Yiyun AU - Lee, Min Wook AU - An, Seongpil AU - Sinha-Ray, Suman AU - Khansari, Shahrzad AU - Joshi, Bhavana AU - Hong, Seungkwan AU - Hong, Joo-Hyun AU - Kim, Jae-Jin AU - Pourdeyhimi, B. AU - Yoon, Sam S. AU - Yarin, Alexander L. T2 - CATALYSIS COMMUNICATIONS AB - Highly porous photocatalytic titania nanoparticle decorated nanofibers were fabricated by electrospinning nylon 6 nanofibers onto flexible substrates and electrospraying TiO2 nanoparticles onto them. Film morphology and crystalline phase were measured by SEM and XRD. The titania films showed excellent photokilling capabilities against E. coli colonies and photodegradation of methylene blue under moderately weak UV exposure (≤ 0.6 mW/cm2 on a 15-cm illumination distance). In addition, solution blowing was used to form soy protein-containing nanofibers which were decorated with silver nanoparticles. These nanofibers demonstrated significant antibacterial activity against E. coli colonies without exposure to UV light. The nano-textured materials developed in this work can find economically viable applications in water purification technology and in biotechnology. The two methods of nanofiber production employed in this work differ in their rate with electrospinning being much slower than the solution blowing. The electrospun nanofiber mats are denser than the solution-blown ones due to a smaller inter-fiber pore size. The antibacterial activity of the two materials produced (electrospun titania nanoparticle decorated nanofibers and silver-nanoparticle-decorated solution-blown nanofibers) are complimentary, as the materials can be effective with and without UV light, respectively. DA - 2013/4/5/ PY - 2013/4/5/ DO - 10.1016/j.catcom.2013.01.002 VL - 34 SP - 35-40 SN - 1873-3905 KW - Antibacterial KW - Electrospinning KW - Titania KW - Soy protein KW - Solution blowing KW - Silver nanoparticles ER - TY - JOUR TI - Supersonic nanoblowing: a new ultra-stiff phase of nylon 6 in 20-50 nm confinement AU - Sinha-Ray, Suman AU - Lee, Min Wook AU - Sinha-Ray, Sumit AU - An, Seongpil AU - Pourdeyhimi, Behnam AU - Yoon, Sam S. AU - Yarin, Alexander L. T2 - JOURNAL OF MATERIALS CHEMISTRY C AB - The 20–50 nm nanofibers hold great promise as functional fabrics, biomedical materials, filters, fuel cell membranes, ultra-speed fiber optics, electronics and sensorics. In our novel process of supersonic solution blowing of nylon-6, 20–50 nm nanofibers are obtained. Here we found a new phase of nylon-6, which differs from the known α-, β-, γ-, δ- and λ-phases, presenting itself as a novel χ-phase. It is characterized by the decrease of CH2 stretching, a shift of –NH stretching, a different type of hydrogen bond and a ten-fold increase in Young's modulus compared to those of post-processed macroscopic nylon fibers. DA - 2013/// PY - 2013/// DO - 10.1039/c3tc30248b VL - 1 IS - 21 SP - 3491-3498 SN - 2050-7534 ER - TY - JOUR TI - Structure-property relationship of extended pi-conjugation of ancillary ligands with and without an electron donor of heteroleptic Ru(II) bipyridyl complexes for high efficiency dye-sensitized solar cells AU - Hussain, Maqbool AU - El-Shafei, Ahmed AU - Islam, Ashraful AU - Han, Liyuan T2 - PHYSICAL CHEMISTRY CHEMICAL PHYSICS AB - Two new heteroleptic Ru(II) bipyridyl complexes MH06 and MH11 were designed, synthesized and characterized for DSSCs. While the ancillary ligand of MH06 was molecularly engineered with a strong electron donating group coupled with an extended π-conjugated system, the ancillary ligand of MH11 contained a longer π-conjugated system only. Molecular modeling, photophysical, and photovoltaic properties were compared under the same experimental conditions against the benchmark N719. In an effort to understand the structure–property relationship, their photovoltaic and photoelectrochemical properties including Jsc, Voc, ground and excited state oxidation potentials, UV-Vis absorption, and molar extinction coefficients were studied. The UV-Vis results showed intense MLCT absorption peaks of MH06 and MH11 in the visible region with a red shift of 12 and 18 nm, respectively, with significantly higher molar extinction coefficients compared to N719. Tetrabutylammonium (TBA) substituted MH11-TBA demonstrated the most efficient IPCE of over 90% in the plateau region covering the entire visible spectrum and extending into the near IR region (ca. 890 nm), which showed a solar-to-power conversion efficiency (η) of 10.06%, significantly higher than that of the benchmark N719 dye (9.32%). The superior performance in terms of the IPCE and Jsc of MH11 can be attributed to the bulky and highly hydrophobic nature of the pyrene-based ancillary ligand, which behaves as a shielding barrier for hole-transport recombination between TiO2 and the electrolyte. In addition, the IMPS results showed that the contribution of dyes to the conduction band shift of the TiO2 level is almost similar, regardless of different substitutions on the bipy-moiety. This implies that the open-circuit photovoltage (Voc) increases with reduced charge recombination in the presence of a thick layer of tetrabutyl ammonium ions (TBA) of the dye anchored on the surface of TiO2. DA - 2013/// PY - 2013/// DO - 10.1039/c3cp51260f VL - 15 IS - 21 SP - 8401-8408 SN - 1463-9084 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84877693518&partnerID=MN8TOARS ER - TY - JOUR TI - Polyvinylidene fluoride-co-chlorotrifluoroethylene and polyvinylidene fluoride-co-hexafluoropropylene nanofiber-coated polypropylene microporous battery separator membranes AU - Lee, Hun AU - Alcoutlabi, Mataz AU - Watson, Jill V. AU - Zhang, Xiangwu T2 - JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS AB - Abstract Nanofiber‐coated polypropylene (PP) separator membranes were prepared by coating a Celgard® microporous PP membrane with electrospun polyvinylidene fluoride‐ co ‐chlorotrifluoroethylene (PVDF‐ co ‐CTFE) and PVDF‐ co ‐CTFE/polyvinylidene fluoride‐ co ‐hexafluoropropylene (PVDF‐ co ‐HFP) nanofibers. Three PVDF polymer solutions of varying compositions were used in the preparation of the nanofiber coatings. Two of the polymer solutions were PVDF‐ co ‐CTFE blends made using different types of PVDF‐ co ‐HFP copolymers. The PVDF‐ co ‐CTFE and PVDF‐ co ‐CTFE/PVDF‐ co ‐HFP blend nanofiber coatings have been found to have comparable adhesion to the PP microporous membrane substrate. The electrolyte uptakes and separator–electrode adhesion properties of nanofiber‐coated membranes were evaluated. Both the electrolyte uptake and the separator–electrode adhesion were improved by the nanofiber coatings. The improvement in electrolyte update capacity is not only related to the gelation capability of the PVDF copolymer nanofibers, but also attributed to the increased porosity and capillary effect on nanofibrous structure of the electrospun nanofiber coatings. Enhancement of the separator–electrode adhesion was owing to the adhesion properties of the copolymer nanofiber coatings. Compared with the PVDF‐ co ‐CTFE/PVDF‐ co ‐HFP blend nanofiber coatings studied, the PVDF‐ co ‐CTFE coating was more effective in improving the electrolyte uptake and separator–electrode adhesion. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 DA - 2013/3/1/ PY - 2013/3/1/ DO - 10.1002/polb.23216 VL - 51 IS - 5 SP - 349-357 SN - 0887-6266 UR - https://publons.com/publon/26924690/ KW - Adhesion KW - Coatings KW - Electrospinning KW - Lithium-ion batteries KW - Nanofibers KW - PVDF-co-CTFE KW - PVDF-co-HFP KW - Separators ER - TY - JOUR TI - Novel atmospheric plasma enhanced chitosan nanofiber/gauze composite wound dressings AU - Nawalakhe, Rupesh AU - Shi, Quan AU - Vitchuli, Narendiran AU - Noar, Jesse AU - Caldwell, Jane M. AU - Breidt, Frederick AU - Bourham, Mohamed A. AU - Zhang, Xiangwu AU - McCord, Marian G. T2 - Journal of Applied Polymer Science AB - Abstract Electrospun chitosan nanofibers were deposited onto atmospheric plasma treated cotton gauze to create a novel composite bandage with higher adhesion, better handling properties, enhanced bioactivity, and moisture management. Plasma treatment of the gauze substrate was performed to improve the durability of the nanofiber/gauze interface. The chitosan nanofibers were electrospun at 3–7% concentration in trifluoroacetic acid. The composite bandages were analyzed using peel, gelbo flex, antimicrobial assay, moisture vapor transmission rate, X‐ray photoelectron spectroscopy (XPS), absorbency, and air permeability tests. The peel test showed that plasma treatment of the substrate increased the adhesion between nanofiber layers and gauze substrate by up to four times. Atmospheric plasma pretreatment of the gauze fabric prior to electrospinning significantly reduced degradation of the nanofiber layer due to repetitive flexing. The chitosan nanofiber layer contributes significantly to the antimicrobial properties of the bandage. Air permeability and moisture vapor transport were reduced due to the presence of a nanofiber layer upon the substrate. XPS of the plasma treated cotton substrate showed formation of active sites on the surface, decrease in carbon content, and increase in oxygen content as compared to the untreated gauze. Deposition of chitosan nanofibers also increased the absorbency of gauze substrate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 DA - 2013/2/25/ PY - 2013/2/25/ DO - 10.1002/app.38804 VL - 129 IS - 2 SP - 916-923 J2 - J. Appl. Polym. Sci. LA - en OP - SN - 0021-8995 UR - http://dx.doi.org/10.1002/app.38804 DB - Crossref KW - biomedical applications KW - biopolymers and renewable polymers KW - nanostructured polymers KW - composites ER - TY - JOUR TI - New N-methyl pyrrole and thiophene based D-pi-A systems for dye-sensitized solar cells AU - Kim, Bo Hyung AU - Freeman, Harold S. T2 - DYES AND PIGMENTS AB - Dye-sensitized solar cells (DSSCs) containing novel DP-T and DP-P organic sensitizers having thiophene and N-methyl pyrrole moieties as π bridges in a D–π–A system were assembled and characterized. Incorporation of a thiophene bridge to give sensitizer DP-T enhanced solar energy capture, while impedance spectroscopy showed a much longer electron recombination lifetime (τ) for the DSSCs based on pyrrole containing sensitizer DP-P. The observed kinetics led to increased open circuit voltage (Voc) for the device based on DP-P, regardless of types of additives (TBP or DCA) employed in the devices. Better photovoltaic performance was achieved using DP-T. DA - 2013/2// PY - 2013/2// DO - 10.1016/j.dyepig.2012.09.001 VL - 96 IS - 2 SP - 313-318 SN - 1873-3743 KW - DSSCs KW - Heterocyclic spacers KW - Recombination lifetime KW - D-pi-A system KW - IPCE KW - TiO2 film ER - TY - JOUR TI - Effects of substituents on the photophysical properties of symmetrical porphyrins AU - Ormond, Alexandra B. AU - Freeman, Harold S. T2 - DYES AND PIGMENTS AB - Porphyrin compounds having groups that mimic the phenolic moiety of m- and p-isomers of 5,10,15,20-tetrakis(hydroxyphenyl) porphyrin (THPP) have been synthesized along with 5,10,15,20-tetrakis(heteroaryl) porphyrins bearing 2-thienyl and 5-thiazolyl groups. Absorption and fluorescence spectroscopy, including fluorescence lifetime (τf) and quantum yield (Φf) measurements, were employed to characterize the singlet excited state of all compounds, using 5,10,15,20-tetraphenylporphyrin (H2TPP) as a standard (Φf = 0.12 in DMF). The generation of singlet oxygen by each porphyrin photosensitizer was measured as the singlet oxygen quantum yield (ΦΔ), using H2TPP as a standard (ΦΔ = 0.64 in DMF). Partition coefficients were determined using 2-octanol as the organic phase and PBS solution as the aqueous phase. Fluorescence quantum yields ranged from 0.01 to 0.18 for all compounds, with heteroaryl porphyrins having the lowest values. Singlet oxygen quantum yields ranged from 0.40 to 0.65, with heteroaryl porphyrins having the highest values, showing them to be better sensitizers than m- and p-THPP. Log P values were all >1 showing higher solubility in the 2-octanol layer. DA - 2013/2// PY - 2013/2// DO - 10.1016/j.dyepig.2012.09.011 VL - 96 IS - 2 SP - 440-448 SN - 1873-3743 KW - Porphyrins KW - Singlet oxygen KW - Quantum yield KW - Fluorescence lifetime KW - Spectroscopy KW - Stokes shift ER - TY - JOUR TI - Effects of bis-carbazole based D-pi-A sensitizers on solar energy capture in DSSCs AU - Kim, Bo Hyung AU - Freeman, Harold S. T2 - PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES AB - A new series of molecular engineered dyes having a carbazole (CA) based bulky donor was synthesized and compared to a previously studied set of dyes having a diphenyl amine (DP) donor for their use in dye sensitized solar cells. In this work, their photophysical, electrochemical, and kinetic properties were measured and molecular modeling methods were used to predict their electronic and physical properties. Regarding the latter, TDDFT studies adopting different exchange correlation functionals were performed to predict solar capture behavior of these sensitizers. The calculated electronic energies showed that the introduction of the bulky CA donor gave a greater negative shift on EHOMO rather than ELUMO, imparting the CA series of dyes a red shifted absorption. On the other hand, tuning of the spacer unit by using different heterocylic rings was sensitive to the shift of ELUMO shift. Better light absorption and driving force of devices based on the CA series were counteracted with negative effects related to the electron injection yield and electron recombination lifetime. The origin of the lower efficiency of the CA dye based devices was investigated in terms of dye load, charge recombination lifetime, in tandem with modeling studies. Results from assessing the effects of different heterocyclic rings, as a π conjugation unit on photovoltaic performance showed that the thiophene unit gave the highest current. On the other hand, CA- and DP-based dyes having an N-methyl pyrrole unit afforded the highest Voc. The best DSSC performance in the CA series was achieved by the thiophene derivative, where η = 3.05% with Jsc = 6.29 mA cm−2, Voc = 673 mV and FF = 0.72 under 100 mW m−2 irradiation. DA - 2013/// PY - 2013/// DO - 10.1039/c2pp25262g VL - 12 IS - 3 SP - 421-431 SN - 1474-9092 ER - TY - JOUR TI - Design, Synthesis, and Pharmacological Screening of Novel Porphyrin Derivatives AU - Fadda, Ahmed A. AU - El-Mekawy, Rasha E. AU - El-Shafei, Ahmed AU - Freeman, Harold S. AU - Hinks, David AU - El-Fedawy, Andmanal T2 - JOURNAL OF CHEMISTRY AB - A series of porphyrin derivatives 2a–f was synthesized, namely, 5,10,15,20-mesotetrakis[p-methoxyphenyl]-21H,23H-porphyrin (2a), 5,10,15,20-mesotetrakis[2,6-dichloro-phenyl]-21H,23H-porphyrin (2b), 5,10,15,20-mesotetrakis[4-hydroxy-3,5-dimethoxyphenyl]-21H,23H-porphyrin (2c), 5,10,15,20-mesotetrakis[3,4-dimethoxyphenyl]-21H,23H-porphyrin (2d), 5,10,15,20-mesotetrakis[2,4-dichlorophenyl]-21H,23H-porphyrin (2e), and 5,10,15,20-mesotetrakis[3,4,5-trimethoxyphenyl]-21H,23H-porphyrin (2f), in high yields using a new method via a capping mechanism. These dyes were used as a model to study the free radical-induced damage of biological membranes and the protective effects of these porphyrins. It was demonstrated that these dyes were effective in the inhibition of the free radical-induced oxidative haemolysis of rat blood cells. Dyes 2d and 2f which bear methoxy functionality exhibited markedly higher antihaemolysis activity than the other analogs. Molecular modeling methods using ZINDO/INDO-1, with a configuration interaction of 26, and TD-DFT using the energy functional B3LYP and the basis set DGTZVP were used to study the vertical electronic excitations of porphyrins 2a–f and it was shown that the calculated using TD-DFT method was in excellent agreement with the experimental results, while the ZINDO method was inferior. Moreover, excellent correlation between the LUMO energy and cytotoxicity of dyes 2a–f was found. DA - 2013/// PY - 2013/// DO - 10.1155/2013/340230 VL - 2013 SP - SN - 2090-9071 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84874820709&partnerID=MN8TOARS ER - TY - JOUR TI - Structure control and performance improvement of carbon nanofibers containing a dispersion of silicon nanoparticles for energy storage AU - Li, Ying AU - Guo, Bingkun AU - Ji, Liwen AU - Lin, Zhan AU - Xu, Guanjie AU - Liang, Yinzheng AU - Zhang, Shu AU - Toprakci, Ozan AU - Hu, Yi AU - Alcoutlabi, Mataz AU - Zhang, Xiangwu T2 - CARBON AB - Si/C composite nanofibers were prepared by electrospinning and carbonization using polyacrylonitrile (PAN) as the spinning medium and carbon precursor. The nanofibers were used as lithium-ion battery anodes to combine the advantages of carbon (long cycle life) and silicon (high storage capacity) materials. The effects of Si particle size, Si content, and carbonization temperature on the structure and electrochemical performance of the anodes were investigated. Results show that anodes made from a 15 wt.% Si/PAN precursor with a Si particle size of 30–50 nm and carbonization temperature of 800 °C exhibit the best performance in terms of high capacity and stable cycling behavior. It is demonstrated that with careful structure control, Si/C composite nanofiber anodes are a promising material for next-generation lithium-ion batteries. DA - 2013/1// PY - 2013/1// DO - 10.1016/j.carbon.2012.08.027 VL - 51 SP - 185-194 SN - 1873-3891 UR - https://publons.com/publon/674384/ ER - TY - JOUR TI - Preparation and properties of nanofiber-coated composite membranes as battery separators via electrospinning AU - Alcoutlabi, Mataz AU - Lee, Hun AU - Watson, Jill V. AU - Zhang, Xiangwu T2 - JOURNAL OF MATERIALS SCIENCE DA - 2013/3// PY - 2013/3// DO - 10.1007/s10853-012-7064-0 VL - 48 IS - 6 SP - 2690-2700 SN - 1573-4803 UR - https://publons.com/publon/7178345/ ER - TY - JOUR TI - Meso-scale deformation and damage in thermally bonded nonwovens AU - Farukh, Farukh AU - Demirci, Emrah AU - Acar, Memis AU - Pourdeyhimi, Behnam AU - Silberschmidt, Vadim V. T2 - JOURNAL OF MATERIALS SCIENCE AB - Thermal bonding is the fastest and the cheapest technique for manufacturing nonwovens. Understanding mechanical behaviour of these materials, especially related to damage, can aid in design of products containing nonwoven parts. A finite element (FE) model incorporating mechanical properties related to damage such as maximum stress and strain at failure of fabric’s fibres would be a powerful design and optimisation tool. In this study, polypropylene-based thermally bonded nonwovens manufactured at optimal processing conditions were used as a model system. A damage behaviour of the nonwoven fabric is governed by its single-fibre properties, which are obtained by conducting tensile tests over a wide range of strain rates. The fibres for the tests were extracted from the nonwoven fabric in a way that a single bond point was attached at both ends of each fibre. Additionally, similar tests were performed on unprocessed fibres, which form the nonwoven. Those experiments not only provided insight into damage mechanisms of fibres in thermally bonded nonwovens but also demonstrated a significant drop in magnitudes of failure stress and respective strain in fibres due to the bonding process. A novel technique was introduced in this study to develop damage criteria based on the deformation and fracture behaviour of a single fibre in a thermally bonded nonwoven fabric. The damage behaviour of a fibrous network within the thermally bonded fabric was simulated with a FE model consisting of a number of fibres attached to two neighbouring bond points. Additionally, various arrangements of fibres’ orientation and material properties were implemented in the model to analyse the respective effects. DA - 2013/3// PY - 2013/3// DO - 10.1007/s10853-012-7013-y VL - 48 IS - 6 SP - 2334-2345 SN - 1573-4803 ER - TY - JOUR TI - Electrospun MgO-loaded carbon nanofibers: Enhanced field electron emission from the fibers in vacuum AU - Aykut, Y. T2 - Journal of Physics and Chemistry of Solids DA - 2013/// PY - 2013/// VL - 74 IS - 2 SP - 328-337 ER - TY - JOUR TI - Fabrication of nanofiber meltblown membranes and their filtration properties AU - Hassan, Mohammad Abouelreesh AU - Yeom, Bong Yeol AU - Wilkie, Arnold AU - Pourdeyhimi, Behnam AU - Khan, Saad. A. T2 - JOURNAL OF MEMBRANE SCIENCE AB - Meltblowing is a unique one-step process for producing self-bonded fibrous nonwoven membranes directly from polymer resins, with average fiber diameter ranging between 1 and 2 μm. Determining routes for making nano- or submicron-fibers using this process are desirable since there are many manufacturing assets that are already in place. It is envisaged that these nonwoven membranes will find applications in critical areas such as medical, hygiene, filtration, bioseparation, and others. In this study, we investigate the influence of different die configurations and operating conditions on fiber and web characteristics. We also report on strategies for reducing the fiber size below one micron to achieve higher filtration quality at lower basis weight relative to the conventional meltblown webs. Their performance is compared to a control meltblown sample produced by using a typical die design. We find that production of nano-meltblown membranes with an average fiber size in the range of 300–500 nm using this new die design is possible and report on process operating conditions that result in such structures. These samples achieve equal filtration efficiencies to that of our control sample at 88% reduced basis weight but at a lower polymer throughput. The lower basis weight also resulted in a lower pressure drop and overall, the new samples exhibited a higher quality factor, twice that of the control. These results show significant promise for the use of nano-meltblown fibers in filtration applications. DA - 2013/1// PY - 2013/1// DO - 10.1016/j.memsci.2012.09.050 VL - 427 SP - 336-344 SN - 1873-3123 KW - Nanofibers KW - Meltbowing KW - Filtration KW - Nonwoven membranes KW - HEPA filters ER -