@article{shabani_yancheshme_ronen_gorga_2021, title={Effect of the Spin-Line Temperature Profile on the Translocation of the Solidification Point and Jet Thinning in Unconfined Melt Electrospinning}, volume={3}, ISSN={["2637-6105"]}, DOI={10.1021/acsapm.0c01082}, abstractNote={This work aims to provide effective strategies and practical tools to control the diameter of fibers, a long-lasting challenge in the application of free surface melt electrospinning, mainly by hig...}, number={1}, journal={ACS APPLIED POLYMER MATERIALS}, author={Shabani, Elnaz and Yancheshme, Amir Azimi and Ronen, Avner and Gorga, Russell E.}, year={2021}, month={Jan}, pages={268–278} } @article{shabani_gorga_2021, title={Effect of the spin-line temperature profile on the mechanical properties of melt electrospun polyethylene fibers}, volume={138}, ISSN={["1097-4628"]}, DOI={10.1002/app.50668}, abstractNote={Abstract}, number={28}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Shabani, Elnaz and Gorga, Russell E.}, year={2021}, month={Jul} } @article{rashid_gorga_krause_2021, title={Mechanical Properties of Electrospun Fibers-A Critical Review}, volume={5}, ISSN={["1527-2648"]}, url={http://dx.doi.org/10.1002/adem.202100153}, DOI={10.1002/adem.202100153}, abstractNote={The mechanical properties of electrospun fibers play an important role in determining their applications. Most of the reported literature measures the mechanical properties of electrospun mats, scaffolds, or films instead of single fibers; however, a basic understanding of the relationship between the mechanical properties of the single fiber and that of the mat is critical to obtain precise information for choosing their application. This Review aims to evaluate the reported mechanical properties of electrospun fibers and the variables that influence those properties. An overview on the recent inputs in the development of mechanical properties of electrospun fibers is given, illustrating attempts to tailor mechanical properties of the fibers and/or mats. The necessity of determining flexible and reliable testing methods to establish testing standards for obtaining consistent and reliable data for both electrospun fibers and mats is also highlighted.}, journal={ADVANCED ENGINEERING MATERIALS}, publisher={Wiley}, author={Rashid, Taslim Ur and Gorga, Russell E. and Krause, Wendy E.}, year={2021}, month={May} } @article{rich_camatcho_stephenson_crew_jur_gorga_2020, title={Evaluation of Infrared Absorption on Thermal Properties of Modified Modacrylic Fibers}, volume={7}, ISSN={["2330-5517"]}, DOI={10.14504/ajr.7.2.5}, abstractNote={A novel modacrylic fiber with the capability to absorb ∼80% of all infrared radiation was evaluated for use in personal thermal comfort applications. Using an infrared (IR) imaging camera to monitor optical changes over time and heat flux measurements, it was concluded that this altered modacrylic fiber possesses both a unique thermal signature as well as increased heat flux compared to 100% cotton. A design of experiments (DOE) was conducted to determine if blending this material with other fibers would result in a fabric with a higher thermal conductivity. It was observed that blends of nylon and the altered modacrylic tended to have the highest conductivity and would provide a cooling effect if used in a garment.}, number={2}, journal={AATCC JOURNAL OF RESEARCH}, author={Rich, Hannah Alexis and Camatcho, Amor M. and Stephenson, Hannah Jean and Crew, Jacob and Jur, Jesse S. and Gorga, Russell E.}, year={2020}, month={Mar} } @article{sadeghifar_venditti_jur_gorga_pawlak_2017, title={Cellulose-Lignin Biodegradable and Flexible UV Protection Film}, volume={5}, ISSN={2168-0485 2168-0485}, url={http://dx.doi.org/10.1021/acssuschemeng.6b02003}, DOI={10.1021/acssuschemeng.6b02003}, abstractNote={There is significant interest in biodegradable and transparent UV protection films from renewable resources for many different applications. Herein, the preparation and characterization of semitransparent flexible cellulose films containing low amounts of covalently bonded lignin with UV-blocking properties are described. Azide modified cellulose dissolved in dimethylacetamide/lithium chloride (DMAc/LiCl) was reacted with propargylated lignin to produce 0.5%, 1%, and 2% by weight lignin containing materials. Cellulose-lignin films were prepared by regeneration in acetone. These covalently bonded cellulose-lignin films were homogeneous, unlike the simple blends of cellulose and lignin. Prepared films showed high UV protection ability. Cellulose film containing 2% lignin showed 100% protection of UV-B (280–320 nm) and more than 90% of UV-A (320–400 nm). The UV protection of prepared films was persistent when exposed to thermal treatment at 120 °C and UV irradiation. Thermogravimetric analysis of the films s...}, number={1}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Sadeghifar, Hasan and Venditti, Richard and Jur, Jesse and Gorga, Russell E. and Pawlak, Joel J.}, year={2017}, month={Nov}, pages={625–631} } @article{bao_clarke_gorga_2016, title={Effect of Constrained Annealing on the Mechanical Properties of Electrospun Poly(ethylene oxide) Webs Containing Multiwalled Carbon Nanotubes}, volume={54}, ISSN={["1099-0488"]}, DOI={10.1002/polb.23960}, abstractNote={ABSTRACT}, number={8}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Bao, Jiaxing and Clarke, Laura I. and Gorga, Russell E.}, year={2016}, month={Apr}, pages={787–796} } @article{viswanath_maity_bochinski_clarke_gorga_2016, title={Enhanced Crystallinity of Polymer Nanofibers without Loss of Nanofibrous Morphology via Heterogeneous Photothermal Annealing}, volume={49}, ISSN={["1520-5835"]}, DOI={10.1021/acs.macromol.6b01655}, abstractNote={Poly(ethylene oxide) electrospun nanofibers with a low concentration of embedded gold nanoparticles (AuNP) were subjected to postfabrication annealing via photothermal heating from the nanoparticles. The results, including nanofibrous mat morphology, crystallinity fraction as a function of annealing time and modality, and average crystallite size, were compared with that for conventional heating at the same average temperature. Maximum crystallinity is achieved more quickly under photothermal heating, and higher maximum crystallinity values, approaching the theoretical maxima for an entangled polymer (∼80%), are obtained. Photothermal heating better preserves the unique nanostructured morphology of the nanofibrous mat whereas significant fiber thickening and loss of porosity occur under conventional annealing treatment. With photothermal heating, heat may be predominantly applied within amorphous material within the fiber, which provides energy for the amorphous chains to reorient and then possibly crysta...}, number={24}, journal={MACROMOLECULES}, author={Viswanath, Vidya and Maity, Somsubhra and Bochinski, Jason R. and Clarke, Laura I. and Gorga, Russell E.}, year={2016}, month={Dec}, pages={9484–9492} } @article{nandgaonkar_wang_fu_krause_wei_gorga_a. lucia_2014, title={A one-pot biosynthesis of reduced graphene oxide (RGO)/bacterial cellulose (BC) nanocomposites}, volume={16}, ISSN={1463-9262 1463-9270}, url={http://dx.doi.org/10.1039/C4GC00264D}, DOI={10.1039/c4gc00264d}, abstractNote={Graphene oxide was successfully reduced to graphene using a bacterial cellulose culture medium that was further processed to fabricate in situ composites of bacterial cellulose/reduced graphene oxide gelatinous hybrids, aerogels, and membranes.}, number={6}, journal={Green Chemistry}, publisher={Royal Society of Chemistry (RSC)}, author={Nandgaonkar, Avinav G. and Wang, Qingqing and Fu, Kun and Krause, Wendy E. and Wei, Qufu and Gorga, Russel and A. Lucia, Lucian}, year={2014}, pages={3195–3201} } @article{abbott_maity_burkey_gorga_bochinski_clarke_2014, title={Blending with Non-responsive Polymers to Incorporate Nanoparticles into Shape-Memory Materials and Enable Photothermal Heating: The Effects of Heterogeneous Temperature Distribution}, volume={215}, ISSN={["1521-3935"]}, DOI={10.1002/macp.201400386}, abstractNote={Blending a shape‐memory polymer (SMP) (e.g., thermoplastic polyurethane) with an immiscible carrier polymer (e.g., poly(ethylene oxide) (PEO) or poly(vinyl alcohol) (PVA)) containing dispersed metal nanoparticles (AuNPs) is a simple approach to enable actuation via photothermal heating. For blends containing up to 90% carrier polymer, the shape‐memory capability can be thermally triggered either conventionally or utilizing internal heating via application of light that is resonant with the particle's surface plasmon resonance. When incorporating nanoparticles in this manner, neither chemical modification of the shape‐memory moiety nor solvation of the SMP is necessary. Actuation times are determined by the particular heterogeneous temperature distribution, which generally occurs under both conventional and photothermal heating methods, but with different spatial patterns. Blending an SMP with PEO containing AuNPs imposes a higher transition temperature (the melting point of PEO), enabling heat generated within the nanoparticle‐containing regions to equilibrate throughout the sample, resulting in performance under photothermal conditions comparable with that achieved in a conventional heating approach. SMP:PVA blends actuate at the SMP transition temperature and the response depends on the size of phase segregation between the PVA and SMP; when decreasing the characteristic size of the segregated regions, heat is efficiently transferred and optimal photothermal performance is observed. image}, number={23}, journal={MACROMOLECULAR CHEMISTRY AND PHYSICS}, author={Abbott, David B. and Maity, Somsubhra and Burkey, Mary T. and Gorga, Russell E. and Bochinski, Jason R. and Clarke, Laura I.}, year={2014}, month={Dec}, pages={2345–2356} } @article{thoppey_gorga_clarke_bochinski_2014, title={Control of the electric field-polymer solution interaction by utilizing ultra-conductive fluids}, volume={55}, ISSN={["1873-2291"]}, DOI={10.1016/j.polymer.2014.10.007}, abstractNote={Dramatically raising the conductivity of a polymer solution by using a salt additive allows control over the electric field-induced jet feed rate when electrospinning from an unconfined fluid without altering the applied voltage. As the solution conductivity increases, the flow rate drops by an order of magnitude. At a high voltage level and fluid conductivity value, the jets undergo a whipping instability over almost the entire path from the source to the collector experiencing only a negligibly short linear region which, along with the flow rate data, indicates that the jet narrows due to the high conductivity. Under these conditions, even while possessing relatively large individual jet feed rates, thin diameter nanofibers (200–300 nm) are readily produced. In contrast with other approaches to obtain narrow fibers from unconfined fluids (e.g., voltage reduction to control feed rate), here the fiber forming jets are present indefinitely. Continuous, scaled up nanofiber production rate of >125× over the traditional single needle electrospinning method is observed from the presence of multiple jets, each possessing a relatively high solution feed rate. These fundamental experiments reveal new pathways for exploring novel electrospinning configurations where the jet feed rate can be controlled by manipulating the solution conductivity.}, number={24}, journal={POLYMER}, author={Thoppey, N. M. and Gorga, R. E. and Clarke, L. I. and Bochinski, J. R.}, year={2014}, month={Nov}, pages={6390–6398} } @article{roman_thoppey_gorga_bochinski_clarke_2013, title={Maximizing Spontaneous Jet Density and Nanofiber Quality in Unconfined Electrospinning: The Role of Interjet Interactions}, volume={46}, ISSN={["1520-5835"]}, DOI={10.1021/ma4013253}, abstractNote={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, allowin...}, number={18}, journal={MACROMOLECULES}, author={Roman, Michael P. and Thoppey, Nagarajan M. and Gorga, Russell E. and Bochinski, Jason R. and Clarke, Laura I.}, year={2013}, month={Sep}, pages={7352–7362} } @article{viswanath_maity_bochinski_clarke_gorga_2013, title={Thermal Annealing of Polymer Nanocomposites via Photothermal Heating: Effects on Crystallinity and Spherulite Morphology}, volume={46}, ISSN={["1520-5835"]}, DOI={10.1021/ma401855v}, abstractNote={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...}, number={21}, journal={MACROMOLECULES}, author={Viswanath, Vidya and Maity, Somsubhra and Bochinski, Jason R. and Clarke, Laura I. and Gorga, Russell E.}, year={2013}, month={Nov}, pages={8596–8607} } @article{thoppey_gorga_bochinski_clarke_2012, title={Effect of Solution Parameters on Spontaneous Jet Formation and Throughput in Edge Electrospinning from a Fluid-Filled Bowl}, volume={45}, ISSN={["1520-5835"]}, DOI={10.1021/ma301207t}, abstractNote={The process of edge electrospinning relies on forming electric-field-induced instabilities (i.e., jets) in a polymer solution bath which act as sources for nanofiber production. As such, it depends...}, number={16}, journal={MACROMOLECULES}, author={Thoppey, Nagarajan M. and Gorga, Russell E. and Bochinski, Jason R. and Clarke, Laura I.}, year={2012}, month={Aug}, pages={6527–6537} } @misc{sas_gorga_joines_thoney_2012, title={Literature review on superhydrophobic self-cleaning surfaces produced by electrospinning}, volume={50}, ISSN={["1099-0488"]}, DOI={10.1002/polb.23070}, abstractNote={Abstract}, number={12}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, publisher={Wiley}, author={Sas, Iurii and Gorga, Russell E. and Joines, Jeff A. and Thoney, Kristin A.}, year={2012}, month={Jun}, pages={824–845} } @article{arvidson_roskov_pate_spontak_khan_gorga_2012, title={Modification of Melt-Spun Isotactic Polypropylene and Poly(lactic acid) Bicomponent Filaments with a Premade Block Copolymer}, volume={45}, ISSN={["1520-5835"]}, DOI={10.1021/ma202246h}, abstractNote={While numerous studies have investigated the effect of adding a block copolymer as a macromolecular surfactant to immiscible polymer blends, no such efforts have sought to alter the properties of melt-spun bicomponent core–sheath filaments with a nonreactive compatibilizing agent. In this study, we examine the effect of adding poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) triblock copolymer to core–sheath filaments consisting of isotactic polypropylene (iPP) and poly(lactic acid) (PLA). Incorporation of the copolymer into blends of iPP/PLA is observed to reduce the size scale of phase separation. Interfacial slip between molten iPP and PLA layers is evaluated by rheology under steady-shear conditions. Addition of SEBS to the PLA sheath during filament formation reduces the tendency of PLA sheaths to crack prior to iPP core failure during tensile testing. In reversed filament configurations, the copolymer does not hinder the development of molecular orientation, related to fiber strength, during ...}, number={2}, journal={MACROMOLECULES}, author={Arvidson, Sara A. and Roskov, Kristen E. and Pate, Jaimin J. and Spontak, Richard J. and Khan, Saad A. and Gorga, Russell E.}, year={2012}, month={Jan}, pages={913–925} } @article{arvidson_wong_gorga_khan_2012, title={Structure, molecular orientation, and resultant mechanical properties in core/sheath poly(lactic acid)/polypropylene composites}, volume={53}, ISSN={["0032-3861"]}, DOI={10.1016/j.polymer.2011.12.042}, abstractNote={We study the coaxial spinning of poly(lactic acid) (PLA) with polypropylene (PP) in a core/sheath configuration. PPcore/PLAsheath and PLAcore/PPsheath fibers maintain the high breaking strength that PP and PLA exhibit individually, showing marked improvement in strength over previous reports of PP/PLA blend fibers. Crystalline morphologies are greatly affected by the location within the fiber (i.e., core, sheath, or spun individually), and hence, co-spinning provides a route to tailor the morphology and fiber diameter beyond that available with single component fibers. A new approach to estimate molecular orientation of core sheath fibers based on the tensile response of the fiber is developed, and indicates that co-spinning PP with PLA results in a synergistic effect with increases in the molecular orientation above that which is possible with spinning either PP or PLA individually.}, number={3}, journal={POLYMER}, author={Arvidson, Sara A. and Wong, Ka C. and Gorga, Russell E. and Khan, Saad A.}, year={2012}, month={Feb}, pages={791–800} } @article{thoppey_bochinski_clarke_gorga_2011, title={Edge electrospinning for high throughput production of quality nanofibers}, volume={22}, ISSN={["1361-6528"]}, DOI={10.1088/0957-4484/22/34/345301}, abstractNote={A novel, simple geometry for high throughput electrospinning from a bowl edge is presented that utilizes a vessel filled with a polymer solution and a concentric cylindrical collector. Successful fiber formation is presented for two different polymer systems with differing solution viscosity and solvent volatility. The process of jet initiation, resultant fiber morphology and fiber production rate are discussed for this unconfined feed approach. Under high voltage initiation, the jets spontaneously form directly on the fluid surface and rearrange along the circumference of the bowl to provide approximately equal spacing between spinning sites. Nanofibers currently produced from bowl electrospinning are identical in quality to those fabricated by traditional needle electrospinning (TNE) with a demonstrated ∼ 40 times increase in the production rate for a single batch of solution due primarily to the presence of many simultaneous jets. In the bowl electrospinning geometry, the electric field pattern and subsequent effective feed rate are very similar to those parameters found under optimized TNE experiments. Consequently, the electrospinning process per jet is directly analogous to that in TNE and thereby results in the same quality of nanofibers.}, number={34}, journal={NANOTECHNOLOGY}, author={Thoppey, N. M. and Bochinski, J. R. and Clarke, L. I. and Gorga, R. E.}, year={2011}, month={Aug} } @article{ramaswamy_clarke_gorga_2011, title={Morphological, mechanical, and electrical properties as a function of thermal bonding in electrospun nanocomposites}, volume={52}, ISSN={["1873-2291"]}, DOI={10.1016/j.polymer.2011.05.023}, abstractNote={Poly lactic acid (PLA) was electrospun with various concentrations of multi-wall carbon nanotubes (MWNT) and thermal bonding was utilized as a post-processing treatment to improve the mechanical and electrical properties of the nanofibrous mats. Thermally bonded fiber–fiber junctions were observed with scanning electron microscopy. An increase in either the strength or modulus of the PLA mats both with and without MWNTs was observed; the maximum modulus and maximum strength occur at different treatment conditions. The electrical conductivity of the MWNT loaded mats showed significant improvement after treatment just below the composite melting point.}, number={14}, journal={POLYMER}, author={Ramaswamy, Sangeetha and Clarke, Laura I. and Gorga, Russell E.}, year={2011}, month={Jun}, pages={3183–3189} } @article{kumar_sandeep_alavi_truong_gorga_2010, title={Effect of Type and Content of Modified Montmorillonite on the Structure and Properties of Bio-Nanocomposite Films Based on Soy Protein Isolate and Montmorillonite}, volume={75}, ISSN={["1750-3841"]}, DOI={10.1111/j.1750-3841.2010.01633.x}, abstractNote={Abstract:  The nonbiodegradable and nonrenewable nature of plastic packaging has led to a renewed interest in packaging materials based on bio‐nanocomposites (biopolymer matrix reinforced with nanoparticles such as layered silicates). Bio‐nanocomposite films based on soy protein isolate (SPI) and modified montmorillonite (MMT) were prepared using melt extrusion. The effect of different type (Cloisite 20A and Cloisite 30B) and content (0% to 15%) of modified MMT on the structure (degree of intercalation and exfoliation) and properties (color, mechanical, dynamic mechanical, thermal stability, and water vapor permeability) of SPI‐MMT bio‐nanocomposite films were investigated. Extrusion of SPI and modified MMTs resulted in bio‐nanocomposites with exfoliated structures at lower MMT content (5%). At higher MMT content (15%), the structure of bio‐nanocomposites ranged from intercalated for Cloisite 20A to disordered intercalated for Cloisite 30B. At an MMT content of 5%, bio‐nanocomposite films based on modified MMTs (Cloisite 20A and Cloisite 30B) had better mechanical (tensile strength and percent elongation at break), dynamic mechanical (glass transition temperature and storage modulus), and water barrier properties as compared to those based on natural MMT (Cloisite Na+). Bio‐nanocomposite films based on 10% Cloisite 30B had mechanical properties comparable to those of some of the plastics that are currently used in food packaging applications. However, much higher WVP values of these films as compared to those of existing plastics might limit the application of these films to packaging of high moisture foods such as fresh fruits and vegetables.}, number={5}, journal={JOURNAL OF FOOD SCIENCE}, author={Kumar, P. and Sandeep, K. P. and Alavi, S. and Truong, V. D. and Gorga, R. E.}, year={2010}, pages={N46–N56} } @article{mccullen_miller_gittard_gorga_pourdeyhimi_narayan_loboa_2010, title={In situ collagen polymerization of layered cell-seeded electrospun scaffolds for bone tissue engineering applications}, volume={16}, DOI={10.1089/ten.tea.2009.0753}, number={5}, journal={Tissue Engineering. Part C, Methods}, author={McCullen, S. D. and Miller, P. R. and Gittard, S. D. and Gorga, Russell and POURDEYHIMI, BEHNAM and Narayan, R. J. and Loboa, E. G.}, year={2010}, pages={1095–1105} } @article{arvidson_khan_gorga_2010, title={Mesomorphic-alpha-Monoclinic Phase Transition in Isotactic Polypropylene: A Study of Processing Effects on Structure and Mechanical Properties}, volume={43}, ISSN={["1520-5835"]}, DOI={10.1021/ma1001645}, abstractNote={We report the enthalpy for the mesomorphic to α-monoclinic phase transition in polypropylene under varying thermal treatments. The mesomorphic phase is created by fiber spinning and rapid quenching methods and identified using wide-angle X-ray diffraction and differential scanning calorimetry. Fiber mesomorphs are found to have a 3-fold increase in enthalpy of transition per gram of mesophase compared with our measurements of quenched polypropylene and previous reports of quenched polypropylene. In addition, systematic tensile testing over a range of spin speeds and polymer morphologies reveals that the presence of mesomorphic regions does not correlate with reduced fiber strength as has been previously suggested. Fiber true stress−true strain curves obtained at varying take-up velocities are compared to determine the “tensile strain shift”, which should theoretically provide a measure of molecular orientation. We find that the tensile strain shift correlates with birefringence, thereby providing an alter...}, number={6}, journal={MACROMOLECULES}, author={Arvidson, Sara A. and Khan, Saad A. and Gorga, Russell E.}, year={2010}, month={Mar}, pages={2916–2924} } @article{kumar_sandeep_alavi_truong_gorga_2010, title={Preparation and characterization of bio-nanocomposite films based on soy protein isolate and montmorillonite using melt extrusion}, volume={100}, ISSN={["1873-5770"]}, DOI={10.1016/j.jfoodeng.2010.04.035}, abstractNote={The non-biodegradable and non-renewable nature of plastic packaging has led to a renewed interest in packaging materials based on bio-nanocomposites (biopolymer matrix reinforced with nanoparticles such as layered silicates). Bio-nanocomposite films based on soy protein isolate (SPI) and montmorillonite (MMT) were prepared using melt extrusion. Effects of the pH of film forming solution, MMT content, and extrusion processing parameters (screw speed and barrel temperature distribution) on the structure and properties of SPI–MMT bio-nanocomposite films were investigated. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used for structural characterization of the films. Properties of the films were determined by tensile testing, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and water vapor barrier measurement. The arrangement of MMT in the soy protein matrix ranged from exfoliated at lower MMT content (5%) to intercalated at higher MMT content (15%). There was a significant improvement in mechanical (tensile strength and percent elongation at break) and dynamic mechanical properties (glass transition temperature and storage modulus), thermal stability, and water vapor permeability of the films with the addition of MMT. The results presented in this study show the feasibility of using bio-nanocomposite technology to improve the properties of biopolymer films based on SPI.}, number={3}, journal={JOURNAL OF FOOD ENGINEERING}, author={Kumar, P. and Sandeep, K. P. and Alavi, S. and Truong, V. D. and Gorga, R. E.}, year={2010}, month={Oct}, pages={480–489} } @article{thoppey_bochinski_clarke_gorga_2010, title={Unconfined fluid electrospun into high quality nanofibers from a plate edge}, volume={51}, ISSN={["0032-3861"]}, DOI={10.1016/j.polymer.2010.07.046}, abstractNote={We demonstrate an easily-implemented, edge-plate geometry for electrospinning and produce high quality nanofibers from unconfined polymer fluids. We show that for electrospinning in general, the electric field gradient, not just the electric field amplitude, is a critical parameter for successful self-initiated jetting. Considering a single spinning site, the edge-plate configuration resulted in the same or a higher fabrication rate as traditional needle electrospinning, while producing nanofibers similar in quality (diameter, diameter distribution, and collected mat porosity); moreover, this novel configuration operates without the possibility of clogging and has high potential for scale-up. We analyze the fundamental physical processes which underlie edge-plate electrospinning, including electric field, working distance, and feed rate dependence and the resultant changes to the linear and whipping regions, and thus to the fiber diameter. We conclude that the edge-plate configuration functions in a remarkably similar manner to traditional needle electrospinning.}, number={21}, journal={POLYMER}, author={Thoppey, Nagarajan Muthuraman and Bochinski, Jason R. and Clarke, Laura I. and Gorga, Russell E.}, year={2010}, month={Oct}, pages={4928–4936} } @article{ajeli_jeddi_rastgo_gorga_2009, title={An analysis of the bending rigidity of warp-knitted fabrics: a comparison of experimental results to a mechanical model}, volume={100}, ISSN={0040-5000 1754-2340}, url={http://dx.doi.org/10.1080/00405000801972374}, DOI={10.1080/00405000801972374}, abstractNote={This study focuses on the bending rigidity of warp-knitted fabrics as a function of knit structure (underlaps length), density (wale and course spacing) and yarn bending properties. Seven standard warp-knitted fabrics are produced with three different densities (Tricot, Locknit, three and four needles Satin, Reveres Locknit, three and four needles Sharkskin). The bending rigidity of the fabrics is measured using a Kawabata evaluation system and an automatic cyclic bending tester. Results show that the bending rigidity increases for the fabrics with a higher density and underlaps length of the front and back guide bars. In addition, a new mechanical model for the bending behaviour of warp-knitted fabrics using an energy method is presented. In this model, the knitted loop structure is assumed to consist of a series of straight and skew yarns simulating legs and underlaps while considering a rigid region lying in the direction of bending. Experimental results show that there is a reasonable agreement between the calculated and measured values for both wale and course directions.}, number={6}, journal={Journal of the Textile Institute}, publisher={Informa UK Limited}, author={Ajeli, S. and Jeddi, Ali. A.A. and Rastgo, A. and Gorga, R. E.}, year={2009}, month={Aug}, pages={496–506} } @article{mccullen_zhu_bernacki_narayan_pourdeyhimi_gorga_loboa_2009, title={Electrospun composite poly(L-lactic acid)/tricalcium phosphate scaffolds induce proliferation and osteogenic differentiation of human adipose-derived stem cells}, volume={4}, ISSN={["1748-605X"]}, DOI={10.1088/1748-6041/4/3/035002}, abstractNote={Development of tissue-engineered bone constructs has recently focused on the use of electrospun composite scaffolds seeded with stem cells from various source tissues. In this study, we fabricated electrospun composite scaffolds consisting of β-tricalcium phosphate (TCP) crystals and poly(L-lactic acid) (PLA) at varying loading levels of TCP (0, 5, 10, 20 wt%) and assessed the composite scaffolds' material properties and ability to induce proliferation and osteogenic differentiation of human adipose-derived stem cells (hASCs) in the presence of osteogenic differentiating medium. The electrospun scaffolds all exhibited a nonwoven structure with an interconnected porous network. With the addition of TCP, the fiber diameter increased with each treatment ranging from 503.39 ± 20.31 nm for 0 wt% TCP to 1267.36 ± 59.03 nm for 20 wt% TCP. Tensile properties of the composite scaffolds were assessed and the overall tensile strength of the neat scaffold (0 wt% TCP) was 847 ± 89.43 kPA; the addition of TCP significantly decreased this value to an average of 350.83 ± 38.57 kPa. As the electrospun composite scaffolds degraded in vitro, TCP was released into the medium with the largest release occurring within the first 6 days. Human ASCs were able to adhere, proliferate and osteogenically differentiate on all scaffold combinations. DNA content increased in a temporal manner for each scaffold over 18 days in culture although for the day 12 timepoint, the 10 wt% TCP scaffold induced the greatest hASC proliferation. Endogenous alkaline phosphatase activity was enhanced on the composite PLA/TCP scaffolds compared to the PLA control particularly by day 18. It was noted that at the highest TCP loading levels of 10 and 20 wt%, there was a dramatic increase in the amount of cell-mediated mineralization compared to the 5 wt% TCP and the neat PLA scaffold. This work suggests that local environment cues provided by the biochemical nature of the scaffold can accelerate the overall osteogenic differentiation of hASCs and encourage rapid ossification.}, number={3}, journal={BIOMEDICAL MATERIALS}, author={McCullen, S. D. and Zhu, Y. and Bernacki, S. H. and Narayan, R. J. and Pourdeyhimi, B. and Gorga, R. E. and Loboa, E. G.}, year={2009}, month={Jun} } @article{mccullen_ramaswamy_clarke_gorga_2009, title={Nanofibrous composites for tissue engineering applications}, volume={1}, ISSN={1939-5116}, url={http://dx.doi.org/10.1002/wnan.39}, DOI={10.1002/wnan.39}, abstractNote={Abstract}, number={4}, journal={Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology}, publisher={Wiley}, author={McCullen, Seth D. and Ramaswamy, Sangeetha and Clarke, Laura I. and Gorga, Russell E.}, year={2009}, month={May}, pages={369–390} } @article{ajeli_jeddi_rastgo_gorga_2008, title={An analysis of the bending rigidity of warp knitted fabrics using a mechanical model}, volume={99}, journal={Journal of the Textile Institute}, author={Ajeli, S. and Jeddi, A. A. and Rastgo, A. and Gorga, R. E.}, year={2008} } @article{ojha_stevens_stano_hoffman_clarke_gorga_2008, title={Characterization of electrical and mechanical properties for coaxial nanofibers with poly(ethylene oxide) (PEO) core and multiwalled carbon nanotube/PEO sheath}, volume={41}, ISSN={["1520-5835"]}, DOI={10.1021/ma702634a}, abstractNote={The present work focuses on the electrical and mechanical characterization of nanocomposite fibers having core−sheath (or bicomponent) morphologies. Owing to their unique mechanical and electrical properties, multiwalled carbon nanotubes (MWNTs) have been utilized in the nanocomposite construction. Submicron diameter nanofibers (200–300 nm) with core−sheath morphology were fabricated from a polymer/MWNT solution and collected in random mats. By constraining the MWNTs to the sheath, significant increases in the mechanical properties were observed at lower MWNT concentrations when compared to mats made from single-layer fibers. The electrical properties of the core−sheath mats showed similar gains, having a critical weight percent more than 10 times lower than that of the single-layer mats.}, number={7}, journal={MACROMOLECULES}, author={Ojha, Satyajeet S. and Stevens, Derrick R. and Stano, Kelly and Hoffman, Torissa and Clarke, Laura I. and Gorga, Russell E.}, year={2008}, month={Apr}, pages={2509–2513} } @article{ojha_stevens_hoffman_stano_klossner_scott_krause_clarke_gorga_2008, title={Fabrication and characterization of electrospun chitosan nanofibers formed via templating with polyethylene oxide}, volume={9}, ISSN={["1526-4602"]}, DOI={10.1021/bm800551q}, abstractNote={Chitosan is an abundantly common, naturally occurring, polysaccharide biopolymer. Its biocompatible, biodegradable, and antimicrobial properties have led to significant research toward biological applications such as drug delivery, artificial tissue scaffolds for functional tissue engineering, and wound-healing dressings. For applications such as tissue scaffolding, formation of highly porous mats of nanometer-sized fibers, such as those fabricated via electrospinning, may be quite important. Previously, strong acidic solvents and blending with synthetic polymers have been used to achieve electrospun nanofibers containing chitosan. As an alternative approach, in this work, polyethylene oxide (PEO) has been used as a template to fabricate chitosan nanofibers by electrospinning in a core-sheath geometry, with the PEO sheath serving as a template for the chitosan core. Solutions of 3 wt % chitosan (in acetic acid) and 4 wt % PEO (in water) were found to have matching rheological properties that enabled efficient core-sheath fiber formation. After removing the PEO sheath by washing with deionized water, chitosan nanofibers were obtained. Electron microscopy confirmed nanofibers of approximately 250 nm diameter with a clear core-sheath geometry before sheath removal, and chitosan nanofibers of approximately 100 nm diameter after washing. The resultant fibers were characterized with IR spectroscopy and X-ray diffraction, and the mechanical and electrical properties were evaluated.}, number={9}, journal={BIOMACROMOLECULES}, author={Ojha, Satyajeet S. and Stevens, Derrick R. and Hoffman, Torissa J. and Stano, Kelly and Klossner, Rebecca and Scott, Mary C. and Krause, Wendy and Clarke, Laura I. and Gorga, Russell E.}, year={2008}, month={Sep}, pages={2523–2529} } @article{ojha_afshari_kotek_gorga_2008, title={Morphology of electrospun nylon-6 nanofibers as a function of molecular weight and processing parameters}, volume={108}, ISSN={["1097-4628"]}, DOI={10.1002/app.27655}, abstractNote={Abstract}, number={1}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Ojha, Satyajeet S. and Afshari, Mehdi and Kotek, Richard and Gorga, Russell E.}, year={2008}, month={Apr}, pages={308–319} } @article{mccullen_stevens_roberts_clarke_bernacki_gorga_loboa_2007, title={Characterization of electrospun nanocomposite scaffolds and biocompatibility with adipose-derived human mesenchymal stem cells}, volume={2}, number={2}, journal={International Journal of Nanomedicine}, author={McCullen, S. D. and Stevens, D. R. and Roberts, W. A. and Clarke, L. I. and Bernacki, S. H. and Gorga, R. E. and Loboa, E. G.}, year={2007}, pages={253–263} } @article{mccullen_stano_stevens_roberts_monteiro-riviere_clarke_gorga_2007, title={Development, optimization, and characterization of electrospun poly(lactic acid) nanofibers containing multi-walled carbon nanotubes}, volume={105}, ISSN={["1097-4628"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000247576000079&KeyUID=WOS:000247576000079}, DOI={10.1002/app.26288}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={McCullen, Seth D. and Stano, Kelly L. and Stevens, Derrick R. and Roberts, Wesley A. and Monteiro-Riviere, Nancy A. and Clarke, Laura I. and Gorga, Russell E.}, year={2007}, month={Aug}, pages={1668–1678} } @article{mccullen_stevens_roberts_ojha_clarke_gorga_2007, title={Morphological, electrical, and mechanical characterization of electrospun nanofiber mats containing multiwalled carbon nanotubes}, volume={40}, ISSN={["1520-5835"]}, DOI={10.1021/ma061735c}, abstractNote={This work focuses on the development of electrically conducting porous nanocomposite structures by the incorporation of multiwalled carbon nanotubes (MWNT) into electrospun poly(ethylene oxide) (PEO) nanofibers. Electron microscopy confirmed the presence of individual aligned MWNT encapsulated within the fibers and showed fiber morphologies with diameters of 100−200 nm. Electrical conductance measurements of the random nanofiber mats showed that by increasing the concentration of MWNT we were able to produce porous nanocomposite structures with dramatically improved electrical conductivity. Above a percolation threshold of 0.365 ± 0.09 MWNT weight percent (wt %) in PEO the conductance increased by a factor of 1012 and then became approximately constant as the concentration of MWNT was further increased. Because of this percolation threshold, for a 1 wt % loading of MWNT, the conductivity is essentially maximized. Mechanical testing confirmed that the tensile strength did not change, and there was a 3-fold...}, number={4}, journal={MACROMOLECULES}, author={McCullen, Seth D. and Stevens, Derrick R. and Roberts, Wesley A. and Ojha, Satyajeet S. and Clarke, Laura I. and Gorga, Russell E.}, year={2007}, month={Feb}, pages={997–1003} } @article{dondero_gorga_2006, title={Morphological and mechanical properties of carbon nanotube/polymer composites via melt compounding}, volume={44}, ISSN={["1099-0488"]}, DOI={10.1002/POLB.20743}, abstractNote={Abstract}, number={5}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Dondero, WE and Gorga, RE}, year={2006}, month={Mar}, pages={864–878} } @misc{hussain_hojjati_okamoto_gorga_2006, title={Review article: Polymer-matrix nanocomposites, processing, manufacturing, and application: An overview}, volume={40}, ISSN={["1530-793X"]}, DOI={10.1177/0021998306067321}, abstractNote={ This review is designed to be a comprehensive source for polymer nanocomposite research, including fundamental structure/property relationships, manufacturing techniques, and applications of polymer nanocomposite materials. In addition to presenting the scientific framework for the advances in polymer nanocomposite research, this review focuses on the scientific principles and mechanisms in relation to the methods of processing and manufacturing with a discussion on commercial applications and health/safety concerns (a critical issue for production and scale-up). Hence, this review offers a comprehensive discussion on technology, modeling, characterization, processing, manufacturing, applications, and health/safety concerns for polymer nanocomposites. }, number={17}, journal={JOURNAL OF COMPOSITE MATERIALS}, author={Hussain, Farzana and Hojjati, Mehdi and Okamoto, Masami and Gorga, Russell E.}, year={2006}, month={Sep}, pages={1511–1575} } @article{gorga_lau_gleason_cohen_2006, title={The effect of nanotube surface coating on poly (methyl methacrylate) with oriented multi-wall carbon nanotubes: A mechanical properties study}, volume={102}, number={2}, journal={Journal of Applied Polymer Science}, author={Gorga, R. E. and Lau, K. and Gleason, K. and Cohen, R. E.}, year={2006}, pages={1413–1418} } @article{gorga_lau_gleason_cohen_2006, title={The importance of interfacial design at the carbon nanotube/polymer composite interface}, volume={102}, ISSN={["0021-8995"]}, DOI={10.1002/app.24272}, abstractNote={Abstract}, number={2}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Gorga, Russell E. and Lau, Kenneth K. S. and Gleason, Karen K. and Cohen, Robert E.}, year={2006}, month={Oct}, pages={1413–1418} } @article{pavoor_gearing_gorga_bellare_cohen_2004, title={Engineering the friction-and-wear behavior of polyelectrolyte multilayer nanoassemblies through block copolymer surface capping, metallic nanoparticles, and multiwall carbon nanotubes}, volume={92}, ISSN={["1097-4628"]}, DOI={10.1002/app.20011}, abstractNote={Abstract}, number={1}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Pavoor, PV and Gearing, BP and Gorga, RE and Bellare, A and Cohen, RE}, year={2004}, month={Apr}, pages={439–448} } @article{gorga_narasimhan_2004, title={Fracture behavior at partially miscible polymer interfaces}, volume={44}, ISSN={["0032-3888"]}, DOI={10.1002/pen.20084}, abstractNote={Abstract}, number={5}, journal={POLYMER ENGINEERING AND SCIENCE}, author={Gorga, RE and Narasimhan, B}, year={2004}, month={May}, pages={929–939} } @article{gorga_cohen_2004, title={Toughness enhancements in poly(methyl methacrylate) by addition of oriented multiwall carbon nanotubes}, volume={42}, ISSN={["0887-6266"]}, DOI={10.1002/polb.20126}, abstractNote={Abstract}, number={14}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, author={Gorga, RE and Cohen, RE}, year={2004}, month={Jul}, pages={2690–2702} } @article{jablonski_gorga_narasimhan_2003, title={Interdiffusion and phase behavior at homopolymer/random copolymer interfaces}, volume={44}, ISSN={["0032-3861"]}, DOI={10.1016/S0032-3861(02)00826-1}, abstractNote={Interdiffusion in polymer bilayers of polystyrene (PS) and the statistically random copolymer poly(styrene-r-4-bromostyrene) (PBS), (C8H(8−x)Brx)N, where x is the mole fraction of brominated repeat units in the copolymer and N the degree of polymerization, was studied using Rutherford backscattering spectroscopy (RBS). PS/PBS bilayers with 0.04