@article{abdala_amin_van zanten_khan_2015, title={Tracer Microrheology Study of a Hydrophobically Modified Comblike Associative Polymer}, volume={31}, ISSN={0743-7463 1520-5827}, url={http://dx.doi.org/10.1021/LA504904N}, DOI={10.1021/la504904n}, abstractNote={The viscoelastic properties of associative polymers are important not only for their use as rheology modifiers but also to understand their complex structure in aqueous media. In this study, the dynamics of comblike hydrophobically modified alkali swellable associative (HASE) polymers are probed using diffusing wave spectroscopy (DWS) based tracer microrheology. DWS-based tracer microrheology accurately probes the dynamics of HASE polymers, and the extracted microrheological moduli versus frequency profile obtained from this technique closely matches that obtained from rotational rheometry measurements. Quantitatively, however, the moduli extracted from DWS-based tracer microrheology measurements are slightly higher than those obtained using rotational rheometry. The creep compliance, elastic modulus, and relaxation time concentration scaling behavior exhibits a power-law dependence. The length scale associated with the elastic to glassy behavior change is obtained from the time-dependent diffusion coefficient. The Zimm-Rouse type scaling is recovered at high frequencies but shows a concentration effect switching from Zimm to more Rouse-like behavior at higher concentrations.}, number={13}, journal={Langmuir}, publisher={American Chemical Society (ACS)}, author={Abdala, Ahmed A. and Amin, Samiul and van Zanten, John H. and Khan, Saad A.}, year={2015}, month={Mar}, pages={3944–3951} }
 @article{tanner_amin_kloxin_zanten_2011, title={Microviscoelasticity of soft repulsive sphere dispersions: Tracer particle microrheology of triblock copolymer micellar liquids and soft crystals}, volume={134}, ISSN={["1089-7690"]}, DOI={10.1063/1.3578183}, abstractNote={Tracer particle microrheology using diffusing wave spectroscopy-based microrheology is demonstrated to be a useful method to study the dynamics of aqueous Pluronic™ F108 solutions, which are viewed as solutions of repulsive soft spheres. The measured zero-shear microviscosity of noncrystallizing micellar dispersions indicates micelle corona dehydration upon increasing temperature. Colloidal sphere thermal motion is shown to be exquisitely sensitive to the onset of crystallization in these micellar dispersions. High temperature dynamics are dominated by an apparent soft repulsive micelle–micelle interaction potential indicating the important role played by lubrication forces and ultimately micelle corona interpenetration and compression at sufficiently high concentrations. The measured microscopic viscoelastic storage and loss moduli are qualitatively similar to those experimentally observed in mechanical measurements on colloidal dispersions and crystals, and calculated from mode coupling theory of colloidal suspensions. The observation of subdiffusive colloidal sphere thermal motion at short time-scales is strong evidence that the observed microscopic viscoelastic properties reflect the dynamics of individual micelles rather than a dispersion of micellar crystallites.}, number={17}, journal={JOURNAL OF CHEMICAL PHYSICS}, author={Tanner, Shaun A. and Amin, Samiul and Kloxin, Christopher J. and Zanten, John H.}, year={2011}, month={May} }
 @article{krishnan_zanten_seifert_lee_spontak_2011, title={Selectively solvated triblock copolymer networks under biaxial strain}, volume={99}, ISSN={["0003-6951"]}, DOI={10.1063/1.3635780}, abstractNote={Triblock copolymers swollen with a midblock-selective solvent provide a test platform by which to interrogate the properties of highly elastic physical gel networks. Here, such networks are biaxially strained and studied by synchrotron small-angle x-ray scattering. Analysis of the form factor reveals that initially spherical micellar cores deform to ellipsoids when strained. The Percus-Yevick hard-sphere model describes the structure factor of micelles exhibiting liquid-like order prior to deformation but requires an attractive potential to match the structure factor under strain. The magnitude of this potential increases with increasing strain, indicating a change in coronal overlap as the network is stretched.}, number={10}, journal={APPLIED PHYSICS LETTERS}, author={Krishnan, Arjun S. and Zanten, John H. and Seifert, Soenke and Lee, Byeongdu and Spontak, Richard J.}, year={2011}, month={Sep} }
 @article{kloxin_zanten_2010, title={High Pressure Phase Diagram of an Aqueous PEO-PPO-PEO Triblock Copolymer System via Probe Diffusion Measurements}, volume={43}, ISSN={["1520-5835"]}, DOI={10.1021/ma902571h}, abstractNote={Phase diagrams of soft fragile materials are typically determined via static structural methods, such as small angle neutron scattering (SANS; Mortensen, K.; Pedersen, J. S. Macromolecules 1993, 26 (4), 805−812), small-angle X-ray scattering (Lodge, T. P.; Pudil, B.; Hanley, K. J. Macromolecules 2002, 35 (12), 4707−4717), or light scattering (Brown, W.; Schillen, K.; Almgren, M.; Hvidt, S.; Bahadur, P. J. Phys. Chem. 1991, 95 (4), 1850−1858). Dynamical methods, such as rheometry, can also be employed since the relaxation spectrum varies greatly from one phase to another. Unfortunately, mechanically disturbing these systems can alter the underlying fragile structures, precluding quiescent state determination. Here, a method for determining soft matter phase diagrams utilizing high-frequency tracer microrheology measurements is demonstrated for an aqueous PEO-PPO-PEO triblock copolymer system over a full range of temperatures and hydrostatic pressures. Since the tracer particle thermal motion reflects the u...}, number={4}, journal={MACROMOLECULES}, author={Kloxin, Christopher J. and Zanten, John H.}, year={2010}, month={Feb}, pages={2084–2087} }
 @article{shankar_klossner_weaver_koga_zanten_krause_colina_tanaka_spontak_2009, title={Competitive hydrogen-bonding in polymer solutions with mixed solvents}, volume={5}, ISSN={["1744-683X"]}, DOI={10.1039/b808479c}, abstractNote={Poly(ethylene oxide) (PEO) coil size is investigated in a binary mixture of solvent molecules capable of cooperatively hydrogen-bonding with each other, as well as with the PEO chains. Viscometry reveals a minimum in zero shear rate solution viscosity at a molar ratio of ∼2:1 water:methanol. This viscosity coincides with a minimum in PEO gyration radius and occurs near the conditions where water/methanol mixtures deviate most markedly from ideal solution behavior. A minimum in polymer mean square end-to-end distance is predicted for polymer solutions composed of two hydrogen-bonding solvents.}, number={2}, journal={SOFT MATTER}, author={Shankar, Ravi and Klossner, Rebecca R. and Weaver, Juan T. and Koga, Tsuyoshi and Zanten, John H. and Krause, Wendy E. and Colina, Coray M. and Tanaka, Fumihiko and Spontak, Richard J.}, year={2009}, pages={304–307} }
 @article{kloxin_zanten_2009, title={Microviscoelasticity of adhesive hard sphere dispersions: Tracer particle microrheology of aqueous Pluronic L64 solutions}, volume={131}, number={13}, journal={Journal of Chemical Physics}, author={Kloxin, C. J. and Zanten, J. H.}, year={2009} }
 @article{mcguffey_otter_zanten_foegeding_2007, title={Solubility and aggregation of commercial alpha-lactalbumin at neutral pH}, volume={17}, ISSN={["1879-0143"]}, DOI={10.1016/j.idairyj.2007.04.003}, abstractNote={The aggregation behavior of two commercial samples of α-lactalbumin (α-La) heated at 95 °C at neutral pH in a complex mineral salt environment was investigated. The objective was to understand the effects of variability between α-La samples and relative concentration of β-lactoglobulin (β-Lg) on aggregate size development, as measured by light scattering and turbidity development. The effect of protein net charge was evaluated with a solubility method and the role of thiol groups was evaluated by reaction with DTNB. The sample with the highest level of β-Lg had higher solubility at pH 6.75 and 6.8, yielded more reactive thiol groups, had a 25% faster first-order rate constant, and formed spherical aggregates with a much higher molecular weight than those produced in the sample containing less β-Lg. Adding increasing quantities of β-Lg to the samples generally decreased reversibility and altered the aggregation process; however, other factors appear to be involved in determining aggregate properties.}, number={10}, journal={INTERNATIONAL DAIRY JOURNAL}, author={McGuffey, Matthew K. and Otter, Donald E. and Zanten, John H. and Foegeding, E. Allen}, year={2007}, month={Oct}, pages={1168–1178} }
 @article{kostko_mchugh_zanten_2006, title={Coil-coil interactions for poly(dimethylsiloxane) in compressible supercritical CO2}, volume={39}, ISSN={["1520-5835"]}, DOI={10.1021/ma0523163}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTCoil−Coil Interactions for Poly(dimethylsiloxane) in Compressible Supercritical CO2A. F. Kostko, M. A. McHugh, and J. H. van ZantenView Author Information Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, Virginia 23284, and Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905 Cite this: Macromolecules 2006, 39, 4, 1657–1659Publication Date (Web):January 24, 2006Publication History Received27 October 2005Revised16 December 2005Published online24 January 2006Published inissue 1 February 2006https://doi.org/10.1021/ma0523163Copyright © 2006 American Chemical SocietyRequest reuse permissionsArticle Views139Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (52 KB) Get e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Dynamic light scattering,Polymers,Quality management,Silicones,Solvents Get e-Alerts}, number={4}, journal={MACROMOLECULES}, author={Kostko, AF and McHugh, MA and Zanten, JH}, year={2006}, month={Feb}, pages={1657–1659} }
 @article{whittier_xu_zanten_kiserow_roberts_2006, title={Viscosity of polystyrene solutions expanded with carbon dioxide}, volume={99}, ISSN={["1097-4628"]}, DOI={10.1002/app.22483}, abstractNote={Abstract}, number={2}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Whittier, RE and Xu, DW and Zanten, JH and Kiserow, DJ and Roberts, GW}, year={2006}, month={Jan}, pages={540–549} }
 @article{li_mchugh_zanten_2005, title={Density-induced phase separation in poly(ethylene-co-1-butene)-dimethyl ether solutions}, volume={38}, ISSN={["1520-5835"]}, DOI={10.1021/ma048166y}, abstractNote={Dynamic light scattering measurements are reported for poly(ethylene-co-20.2 mol % 1-butene) (PEB10) in dimethyl ether (DME) at 110−170 °C and pressures to 2500 bar. The cloud-point curve for the PEB10−DME system exhibits both low- and high-pressure upper consolute solution temperature (UCST) branches. The polymer infinite dilution translational diffusion coefficient, D0, increases with increasing temperature and decreasing pressure as expected. The observed variation of D0 is inversely proportional to the solvent viscosity, indicating that the polymer coil hydrodynamic size is independent of temperature and pressure. The dynamic second virial coefficient, kD, which represents a balance between thermodynamic interactions and hydrodynamic forces, displays values that lie within the bounds expected for ϑ and good solvent conditions. While the low-pressure UCST is classical in that the polymer−solvent interactions become unfavorable upon approach to this phase boundary, the high-pressure UCST branch exhibits...}, number={7}, journal={MACROMOLECULES}, author={Li, D and McHugh, MA and Zanten, JH}, year={2005}, month={Apr}, pages={2837–2843} }
 @article{dinoia_park_mchugh_zanten_2005, title={Observation of polymer chain contraction near the overlap concentration}, volume={38}, ISSN={["1520-5835"]}, DOI={10.1021/ma051216u}, abstractNote={Department of Chemical Engineering, Johns HopkinsUniversity, Baltimore, Maryland 21218; Department ofPolymer Science & Engineering, Kumoh National Universityof Technology, Kyungbuk, Korea; Department of ChemicalEngineering, Virginia Commonwealth University,Richmond, Virginia 23284; and Department of Chemicaland Biomolecular Engineering, North Carolina StateUniversity, Raleigh, North Carolina 27695-7905Received June 9, 2005Revised Manuscript Received August 2, 2005}, number={22}, journal={MACROMOLECULES}, author={DiNoia, TP and Park, IH and McHugh, MA and Zanten, JH}, year={2005}, month={Nov}, pages={9393–9395} }
 @article{zanten_amin_abdala_2004, title={Brownian motion of colloidal spheres in aqueous PEO solutions}, volume={37}, ISSN={["1520-5835"]}, DOI={10.1021/ma035250p}, abstractNote={The Brownian motion of colloidal spheres in aqueous poly(ethylene oxide) (PEO) solutions ranging in concentration from 0.2 to 15 wt % is measured with diffusing wave spectroscopy over more than 6 decades of time. The measured colloidal sphere mean-squared displacements are shown to satisfy the generalized Stokes−Einstein relation that relates the particle mean-squared displacement to the polymer solution shear modulus as the microrheological creep compliance calculated from the colloidal sphere Brownian motion was found to agree with that measured by mechanical rheometry. The microrheological zero shear viscosity concentration dependence for the entangled solution regime, η ∼ c4.7, is in agreement with that reported by others from mechanical rheometry measurements on polymer−good solvent solutions and is stronger than the tube model prediction, η ∼ c3.9. Essentially the entire deviation between the predicted and measured entangled solution regime zero shear viscosity concentration dependence is accounted ...}, number={10}, journal={MACROMOLECULES}, author={Zanten, JH and Amin, S and Abdala, AA}, year={2004}, month={May}, pages={3874–3880} }
 @article{kermis_li_guney-altay_park_zanten_mchugh_2004, title={High-pressure dynamic light scattering of poly(ethylene-co-1-butene) in ethane, propane, butane, and pentane at 130 degrees C and kilobar pressures}, volume={37}, ISSN={["1520-5835"]}, DOI={10.1021/ma0487103}, abstractNote={Poly(ethylene-co-1-butene) diffusion in ethane, propane, butane, and pentane indicates that ethane solutions are remarkably different. For propane, butane, and pentane the dynamic second virial coefficient, kD, is negative near the phase boundary, increases rapidly to positive values within ∼100 to 200 bar of the respective phase boundary, and approaches a constant value at high pressures. For ethane, kD is also negative near the phase boundary; it increases at a slower rate and becomes only slightly greater than zero. kD for all four solvents superpose when plotted against “methyl” molar density, suggesting thermodynamic interactions rather than hydrodynamic forces dominate. For propane, butane, and pentane the hydrodynamic radius, RH, also starts at a low value near the phase boundary and increases to the same value for all three alkanes. For ethane RH is ∼30% smaller than those for the higher alkanes, reflecting the poor quality of ethane even 1000 bar above the phase boundary.}, number={24}, journal={MACROMOLECULES}, author={Kermis, TW and Li, D and Guney-Altay, O and Park, IH and Zanten, JH and McHugh, MA}, year={2004}, month={Nov}, pages={9123–9131} }
 @article{lenhart_dunkers_zanten_parnas_2003, title={Characterization of sizing layers and buried polymer/sizing/substrate interfacial regions using a localized fluorescent probe}, volume={257}, ISSN={["0021-9797"]}, DOI={10.1016/S0021-9797(02)00035-8}, abstractNote={A novel technique is described to investigate buried polymer/sizing/substrate interfacial regions, in situ, by localizing a fluorescent probe molecule in the sizing layer. Epoxy functional silane coupling agent multilayers were deposited on glass microscope cover slips and doped with small levels of a fluorescently labeled silane coupling agent (FLSCA). The emission of the grafted FLSCA was dependent on the silane layer thickness, showing blue-shifted emission with decreasing thickness. The fluorescent results suggest that thinner layers were more tightly bound to the glass surface. The layers were also characterized by scanning electron microscopy, contact angle, and thermogravimetric analysis (TGA). When the FLSCA-doped silane layers were immersed in epoxy resin, a blue shift in emission occurred during resin cure, indicating the potential to study interfacial chemistry, in situ. Thicker silane layers exhibited smaller fluorescence shifts during cure, suggesting incomplete resin penetration into the thickest silane layers.}, number={2}, journal={JOURNAL OF COLLOID AND INTERFACE SCIENCE}, author={Lenhart, JL and Dunkers, JP and Zanten, JH and Parnas, RS}, year={2003}, month={Jan}, pages={398–407} }
 @article{dinoia_zanten_kline_garach-domech_mchugh_wright_fetters_2003, title={Impact of supercritical fluid solvent quality on polymer conformation in semidilute solutions: SANS data for poly(ethylene-co-1-butene) in dimethyl ether to kilobar pressures}, volume={36}, ISSN={["1520-5835"]}, DOI={10.1021/ma034690d}, abstractNote={Phase behavior and small-angle neutron scattering (SANS) measurements are reported for poly(ethylene-co-20.2 mol % 1-butene) (PEB10) dissolved in supercritical dimethyl ether (DME). The phase boundary is located at pressures near 600 bar at 130 °C, and it exhibits a minimum in temperature near 105 °C where the cloud-point pressure rises sharply. Neutron scattering is performed with a high- pressure scattering cell designed for a large incident beam diameter, good mixing, and real-time viewing of the solution to ensure single-phase operation. The SANS results suggest significant variations in intramolecular correlations exist at length scales proportional to a few monomer units although the radius of gyration remains close to the unperturbed value at pressures from the cloud point to as high as 2400 bar. As expected, the intermolecular correlation length grows rapidly on approach to the phase boundary. The phase behavior and SANS data suggest that DME is very poor quality solvent even at high solvent densities.}, number={19}, journal={MACROMOLECULES}, author={DiNoia, TP and Zanten, JH and Kline, SR and Garach-Domech, A and McHugh, MA and Wright, PJ and Fetters, LJ}, year={2003}, month={Sep}, pages={7372–7378} }
 @article{wang_singh_zanten_2002, title={Aggregation rate measurements by zero-angle time-resolved multiangle laser light scattering}, volume={18}, ISSN={["0743-7463"]}, DOI={10.1021/la011207o}, abstractNote={A new method for determining second-order aggregation rate constants via time-resolved multiangle laser light scattering is introduced. A major advantage of this approach is that second-order aggregation rate constants are determined without any assumptions regarding the dimer intraparticle interference or form factor. The second-order aggregation rate constants are calculated from the temporal variation of the zero-angle excess Rayleigh ratio within the context of von Smoluchowski's well-established model of colloidal aggregation. The new method is illustrated with two systems: (1) GM1-bearing liposomes aggregated in the presence of the cholera toxin B subunit and (2) sulfonated polystyrene latex aggregated in the presence of CaCl 2 . Whereas the method is demonstrated to be particularly well-suited for investigating slow aggregation processes, rapid aggregation processes are also accessible if proper precautions are taken.}, number={6}, journal={LANGMUIR}, author={Wang, K and Singh, AK and Zanten, JH}, year={2002}, month={Mar}, pages={2421–2425} }
 @article{lai_zanten_2002, title={Evidence of lipoplex dissociation in liquid formulations}, volume={91}, ISSN={["0022-3549"]}, DOI={10.1002/jps.10108}, abstractNote={Aggregation is typically cited as the root cause of lipoplex transfection efficacy loss in liquid formulations. Typically, this conclusion is based on observed increases in lipoplex hydrodynamic size. A more detailed physical characterization of the lipoplex transfection efficacy diminution has previously never been conducted. As a result, most research has focused on either methods of forming more stable lipoplex formulations or preservation methods such as lyophilization. These studies typically consider the use of stabilizing additives, such as polymer and sugar molecules, to enhance the efficacy of lipoplex dispersions. This report details a recent multiangle laser light scattering study of the temporal evolution of lipoplex geometric size (i.e., radius of gyration) and molar mass in liquid-based formulations over several months. The results indicate that for the lipoplex systems considered, the primary factor underlying the long-term loss of lipoplex transfection efficiency is actually lipoplex dissociation caused by a decrease in the observed molar mass of some lipoplex formulations. The increasing geometric sizes observed are actually the result of lipoplex dissociation combined with an increase in volume. That is, the lipoplexes lose mass and expand in volume, leading to a less dense lipoplex structure over time.}, number={5}, journal={JOURNAL OF PHARMACEUTICAL SCIENCES}, author={Lai, E and Zanten, JH}, year={2002}, month={May}, pages={1225–1232} }
 @article{lai_zanten_2002, title={Real time monitoring of lipoplex molar mass, size and density}, volume={82}, ISSN={["0168-3659"]}, DOI={10.1016/S0168-3659(02)00104-9}, abstractNote={Time-resolved multiangle laser light scattering (TR-MALLS) is used to monitor the temporal variation of DNA/cationic liposome lipoplex molar masses and geometric sizes throughout the complexation process. The measured molar masses and geometric sizes are in turn used to estimate lipoplex density. The DNA/cationic lipid charge ratio is found to be the primary factor governing lipoplex formation kinetics and the final lipoplex molar mass, geometric size and density. Charge ratios near unity lead to a growing kinetic regime in which initially formed primary lipoplexes undergo further aggregation eventually forming large molar mass lipoplexes of high density, while charge ratios very far from unity yield low molar mass lipoplexes of lower density. It is also noted that solvent composition can play a significant role in the lipoplex formation process with lipoplexes formed in ion-containing media being larger and denser than those formed in dextrose solution.}, number={1}, journal={JOURNAL OF CONTROLLED RELEASE}, author={Lai, E and Zanten, JH}, year={2002}, month={Jul}, pages={149–158} }
 @article{lenhart_zanten_dunkers_parnas_2002, title={Using a localized fluorescent dye to probe the glass/resin interphase}, volume={23}, ISSN={["0272-8397"]}, DOI={10.1002/pc.10456}, abstractNote={Abstract}, number={4}, journal={POLYMER COMPOSITES}, author={Lenhart, JL and Zanten, JH and Dunkers, JP and Parnas, RS}, year={2002}, month={Aug}, pages={555–563} }
 @article{amin_kermis_zanten_dees_zanten_2001, title={Concentration fluctuations in CTAB/NaSal solutions}, volume={17}, ISSN={["0743-7463"]}, DOI={10.1021/la010844b}, abstractNote={This report details a dynamic light scattering investigation of CTAB/NaSal solution concentration fluctuations over a wide range of CTAB concentration and NaSal:CTAB mole ratio. Two distinct relaxation times are observed for CTAB concentrations greater than or equal to 0.02 M. The hydrodynamic correlation length, ξH, associated with the fast relaxation mode is observed to depend on both the CTAB concentration and NaSal:CTAB mole ratio. In particular, the CTAB concentration scaling of ξH is shown to vary in a nonmonotonic manner with the NaSal:CTAB mole ratio. The scaling exponent is found to range from −0.25 to −0.67, where its minimum value is found for NaSal:CTAB mole ratios near 1.5−2.0. The amplitude of the slow relaxation mode is strongly correlated with the hydrodynamic correlation length for NaSal:CTAB mole ratios less than or equal to 2 thereby suggesting polymer/polyelectrolyte solution behavior at these conditions. The overall picture that emerges is that of a system where the competition among ...}, number={26}, journal={LANGMUIR}, author={Amin, S and Kermis, TW and Zanten, RM and Dees, SJ and Zanten, JH}, year={2001}, month={Dec}, pages={8055–8061} }
 @article{dunkers_lenhart_kueh_zanten_advani_parnas_2001, title={Fiber optic flow and cure sensing for liquid composite molding}, volume={35}, ISSN={["0143-8166"]}, DOI={10.1016/S0143-8166(00)00110-X}, abstractNote={The Polymer Composites group at the National Institute of Standards and Technology has efforts in both on-line flow and cure sensing for liquid composite molding. For our flow program, a novel fiber optic real-time sensor system has been developed that can sense resin at various locations on a single fiber using long-period gratings and a polychromatic source. The sensor operation and characterization will be discussed along with sensor performance during mold filling with various types of reinforcement. The cure sensing program focuses on the interface-sensitive fluorescence response of a dye molecule grafted to a high-index glass fiber. The fluorescence emission of the fluorophore undergoes a blue shift as the resin cures. The fluorescence sensor is made by grafting a silane functional fluorophore onto the surface of the glass with close attention to layer thickness. Fluorescence emission of the grafted fluorophore film is shown to be sensitive to epoxy resin cure, co-silane, and layer thickness. The response of the grafted fluorophore to cure on a high-index fiber is demonstrated.}, number={2}, journal={OPTICS AND LASERS IN ENGINEERING}, author={Dunkers, JP and Lenhart, JL and Kueh, SR and Zanten, JH and Advani, SG and Parnas, RS}, year={2001}, month={Feb}, pages={91–104} }
 @article{lai_zanten_2001, title={Monitoring DNA/poly-L-lysine polyplex formation with time-resolved multiangle laser light scattering}, volume={80}, ISSN={["0006-3495"]}, DOI={10.1016/s0006-3495(01)76065-1}, abstractNote={Nonviral DNA complexes show promise as alternative and attractive gene delivery vectors for treating genetic diseases. Nonviral DNA complexes are typically formed by combining DNA with various condensing/complexing agents such as lipids, polyelectrolytes, polymers, polypeptides, and surfactants in solution. DNA/poly-L-lysine polyplex formation kinetics are probed by time-resolved multiangle laser light scattering (TR-MALLS), which yields the time evolution of the supramolecular complex mass and geometric size. Primary polyplexes whose geometric size is smaller than individual DNA molecules in solution are formed very rapidly upon mixing DNA and poly-L-lysine. Over time, these primary polyplexes aggregate into larger structures whose ultimate size is determined primarily by the relative concentrations of DNA and poly-L-lysine. This final polyplex size varies with the DNA/poly-L-lysine mass ratio in a non-monotonic fashion, with the maximum polyplex size occurring at a DNA/poly-L-lysine mass ratio of approximately two to three (charge ratio near unity). The utility of TR-MALLS for monitoring the temporal evolution of DNA loading and supramolecular complex size growth (mean square radius and molar mass) throughout the DNA/poly-L-lysine polyplex formation process is demonstrated. The polyplex DNA loading and size, both geometric and molar mass, are key to understanding the transfection process and for developing optimal gene therapy vectors.}, number={2}, journal={BIOPHYSICAL JOURNAL}, author={Lai, E and Zanten, JH}, year={2001}, month={Feb}, pages={864–873} }
 @article{lenhart_zanten_dunkers_parnas_2001, title={Studying the buried interfacial region with an immobilized fluorescence probe}, volume={34}, ISSN={["0024-9297"]}, DOI={10.1021/ma0015572}, abstractNote={The properties of a buried epoxy/glass interfacial region were studied by covalently grafting a fluorescent probe to the glass surface. A (dimethylamino)nitrostilbene (DMANS) fluorophore was tethered to a triethoxysilane coupling agent, generating a fluorescently labeled silane coupling agent (FLSCA). The glass surface was coated with a silane layer that was doped with small amounts of FLSCA. The emission maximum from grafted FLSCA was different than when the dye was dissolved in bulk resin, suggesting a different interfacial structure. When the dye was dissolved in bulk cured resin, a red shift in the emission maximum was detected as the resin temperature was increased. A distinct break in the fluorescence maximum vs temperature slope was detected at the glass transition of the bulk resin. The slope became larger at temperatures above Tg. A similar break was observed from grafted FLSCA, suggesting that the grafted dye was sensitive to an apparent glass transition in the buried interfacial region. The temperature of the apparent interfacial transition measured by grafted FLSCA could be lower or higher than the bulk polymer T g , depending on the initial structure of the grafted silane layer.}, number={7}, journal={MACROMOLECULES}, author={Lenhart, JL and Zanten, JH and Dunkers, JP and Parnas, RS}, year={2001}, month={Mar}, pages={2225–2231} }
 @article{zanten_rufener_2000, title={Brownian motion in a single relaxation time Maxwell fluid}, volume={62}, ISSN={["1550-2376"]}, DOI={10.1103/physreve.62.5389}, abstractNote={A simple model of Brownian motion in a single relaxation time Maxwell fluid is described and compared to diffusing wave spectroscopy measurements of colloidal motion in representative viscoelastic fluids, namely, CTAB/KBr wormlike micelle solutions. The experimentally measured Brownian motion conforms to the model predictions at long times (low frequencies) and is an additional confirmation of the essentially Maxwellian stress relaxation behavior of wormlike micelle solutions at low frequencies. Surprisingly, the Maxwell model predicts a plateau onset time which, while capable of reducing the measured mean-square displacements to a master curve, also grossly underestimates the actual plateau onset time. The predicted rescaling is shown to be essentially that also predicted by the Doi-Edwards tube model for polymer solutions under good solvent (excluded volume) conditions where a more proper accounting of the short-time dynamics is made. This indicates that the success of the predicted Maxwell model plateau onset time rescaling is purely fortuitous.}, number={4}, journal={PHYSICAL REVIEW E}, author={Zanten, JH and Rufener, KP}, year={2000}, month={Oct}, pages={5389–5396} }
 @article{lenhart_zanten_dunkers_zimba_james_pollack_parnas_2000, title={Immobilizing a fluorescent dye offers potential to investigate the glass/resin interface}, volume={221}, ISSN={["0021-9797"]}, DOI={10.1006/jcis.1999.6577}, abstractNote={Silane coupling agents are commonly applied to glass fibers to promote fiber/resin adhesion and enhance durability in composite parts. In this study, a coupling agent multilayer on glass was doped with trace levels of the dimethylaminonitrostilbene (DMANS) fluorophore. The fluorophore was immobilized on the glass surface by tethering the molecule to a triethoxy silane coupling agent, creating the DMANS/silane coupling agent molecule (DMSCA). DMSCA was then diluted with commonly used coupling agents and grafted to a glass microscope coverslip to create a model composite interface. A 53-nm blue shift in fluorescence from the immobilized DMSCA can be followed during cure of an epoxy resin overlayer, giving this technique potential to monitor the properties of the fiber/resin interface during composite processing. Contact angle measurements on these coupling agent layers were similar in the presence or absence of the DMSCA molecule, suggesting that trace levels of the fluorescent probe did not affect the structure of the layer. The immobilized DMSCA molecule behaved similarly to the DMANS precursor in solution. Both showed longer wavelength fluorescence in more polar environments. Copyright 2000 Academic Press.}, number={1}, journal={JOURNAL OF COLLOID AND INTERFACE SCIENCE}, author={Lenhart, JL and Zanten, JH and Dunkers, JP and Zimba, CG and James, CA and Pollack, SK and Parnas, RS}, year={2000}, month={Jan}, pages={75–86} }
 @article{lenhart_zanten_dunkers_parnas_2000, title={Interfacial response of a fluorescent dye grafted to glass}, volume={16}, ISSN={["0743-7463"]}, DOI={10.1021/la000553n}, abstractNote={The properties of an epoxy/glass interfacial region are studied by covalently grafting a fluorescent probe to the glass surface. A dimethylaminonitrostilbene fluorophore is tethered to a triethoxysilane-coupling agent, generating a fluorescently labeled silane coupling agent (FLSCA). The glass surface is coated with a silane layer that was doped with small amounts of FLSCA. When the FLSCA-doped, silane-coated glass is immersed in epoxy resin, a 42-nm blue shift in fluorescence occurs during resin cure over the grafted FLSCA layer. When the dye is dissolved in bulk epoxy a 64-nm blue shift occurs during resin cure. The difference in blue shift is attributed to higher polarity and enhanced mobility in the buried interface.}, number={21}, journal={LANGMUIR}, author={Lenhart, JL and Zanten, JH and Dunkers, JP and Parnas, RS}, year={2000}, month={Oct}, pages={8145–8152} }
 @article{dinoia_kirby_zanten_mchugh_2000, title={SANS study of polymer-supercritical fluid solutions: Transitions from liquid to supercritical fluid solvent quality}, volume={33}, ISSN={["0024-9297"]}, DOI={10.1021/ma000240z}, abstractNote={Phase behavior and small-angle neutron scattering (SANS) measurements are reported for poly(ethylene-co-1-butene) (PEB) dissolved in pentane, pentane plus ethane, and supercritical ethane to pressu...}, number={17}, journal={MACROMOLECULES}, author={DiNoia, TP and Kirby, CF and Zanten, JH and McHugh, MA}, year={2000}, month={Aug}, pages={6321–6329} }