Search Results - "White, Ronald P"

Polymer Free Volume and Its Connection to the Glass Transition by White, Ronald P, Lipson, Jane E. G

“…In this Perspective we summarize the most widely used definitions of free volume and illustrate the differences between them, including the important…”
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Substrate Roughness Speeds Up Segmental Dynamics of Thin Polymer Films by Panagopoulou, Anna, Rodríguez-Tinoco, Cristian, White, Ronald P, Lipson, Jane E G, Napolitano, Simone

“…We show that the segmental mobility of thin films of poly(4-chlorostyrene) prepared under nonequilibrium conditions gets enhanced in the proximity of rough…”
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Dynamics across a Free Surface Reflect Interplay between Density and Cooperative Length: Application to Polystyrene by White, Ronald P, Lipson, Jane E. G

“…It is now generally agreed that the most dramatic influence of a free surface on local relaxation dynamics occurs over the first 10 nm from the surface. Using…”
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Effect of Interfaces on the Glass Transition of Supported and Freestanding Polymer Thin Films by White, Ronald P, Price, Christopher C, Lipson, Jane E. G

“…We investigate the glass transition behavior in polymer thin films using a model equation-of-state approach, which involves molecular parameters whose values…”
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Origins of Unusual Phase Behavior in Polymer/Ionic Liquid Solutions by White, Ronald P, Lipson, Jane E. G

“…Recent experimental studies [ Lee Macromolecules 2012, 45, 3627−3633 ] on polymer/IL solutions of poly(ethylene oxide) (PEO) and 1-ethyl-3-methylimidazolium…”
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Connecting Pressure-Dependent Dynamics to Dynamics under Confinement: The Cooperative Free Volume Model Applied to Poly(4-chlorostyrene) Bulk and Thin Films by White, Ronald P, Lipson, Jane E. G

“…We apply our cooperative free volume (CFV) rate model for pressure-dependent dynamics to describe the relaxation times for poly­(4-chlorostyrene) (P4ClS) bulk…”
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To Understand Film Dynamics Look to the Bulk by White, Ronald P., Lipson, Jane E. G.

“…We show that shifts in dynamics of confined systems relative to that of the bulk material originate in the properties of bulk alone, and exhibit the same form…”
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Why Volume and Dynamics Decouple in Nanocomposite Matrices: Space that Cannot Be Accessed is Not Free by White, Ronald P, Lipson, Jane E G

“…Polymer nanocomposites have important material applications and are an ongoing focus of many molecular level investigations, however, puzzling experimental…”
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Pressure-Dependent Dynamics of Polymer Melts from Arrhenius to Non-Arrhenius: The Cooperative Free Volume Rate Equation Tested against Simulation Data by White, Ronald P, Lipson, Jane E. G

“…We apply the cooperative free volume (CFV) model to analyze the segmental relaxation times, τ­(T,V), of a model 20-mer polymer melt simulated via molecular…”
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The cooperative free volume rate model for segmental dynamics: Application to glass-forming liquids and connections with the density scaling approach by White, Ronald P., Lipson, Jane E. G.

“… In this paper, we apply the cooperative free volume (CFV) rate model for pressure-dependent dynamics of glass-forming liquids and polymer melts. We analyze…”
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A Simple New Way To Account for Free Volume in Glassy Dynamics: Model-Free Estimation of the Close-Packed Volume from PVT Data by White, Ronald P, Lipson, Jane E. G

“…In this article we focus on the important role of well-defined free volume (V free) in dictating the structural relaxation times, τ, of glass-forming liquids…”
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A Simulation Method for Calculating the Absolute Entropy and Free Energy of Fluids: Application to Liquid Argon and Water by White, Ronald P., Meirovitch, Hagai, Scheraga, Harold A.

“…The hypothetical scanning (HS) method is a general approach for calculating the absolute entropy and free energy by analyzing Boltzmann samples obtained by…”
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Free Volume, Cohesive Energy Density, and Internal Pressure as Predictors of Polymer Miscibility by White, Ronald P, Lipson, Jane E. G

“…In this paper, we illuminate and predict trends in polymer miscibility using our model understanding of pure component properties. We introduce a new metric…”
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Experimental Test of the Cooperative Free Volume Rate Model under 1D Confinement: The Interplay of Free Volume, Temperature, and Polymer Film Thickness in Driving Segmental Mobility by Debot, Alice, White, Ronald P, Lipson, Jane E. G, Napolitano, Simone

“…We show that the Cooperative Free Volume (CFV) rate model, successful at modeling pressure-dependent dynamics, can be employed to describe the temperature and…”
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How Free Volume Does Influence the Dynamics of Glass Forming Liquids by White, Ronald P, Lipson, Jane E. G

“…In this article we show that inverse free volume is a natural variable for analyzing relaxation data on glass-forming liquids, and that systems obey the…”
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Experimental and Modeling Comparison of the Dynamics of Capped and Freestanding Poly(2-chlorostyrene) Films by Song, Zijian, White, Ronald P, Lipson, Jane E. G, Napolitano, Simone

“…Proximity to a nonrepulsive wall is commonly considered to cause slower dynamics, which should lead to greater relaxation times for capped thin polymer films…”
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Thermodynamics of Model PαMSAN/dPMMA Blend: A Combined Study by SANS, Ellipsometry, and Locally Correlated Lattice (LCL) Theory by White, Ronald P, Aoki, Yutaka, Higgins, Julia S, Keddie, Joseph L, Lipson, Jane E. G, Cabral, João T

“…We combine experiment and theory to elucidate how small, local, structural changes can impact miscibility in polymer blends. Small-angle neutron scattering…”
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Connecting Theory and Experiment To Understand Miscibility in Polymer and Small Molecule Mixtures by Lipson, Jane E. G, White, Ronald P

“…In this article, we discuss applications of our locally correlated lattice (LCL) theory to problems involving small molecules (e.g., simple alkanes), ionic…”
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Calculation of the entropy of lattice polymer models from Monte Carlo trajectories by White, Ronald P., Funt, Jason, Meirovitch, Hagai

“…While lattice models are used extensively for macromolecules (synthetic polymers proteins, etc.), calculation of the absolute entropy, S, and the free energy,…”
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Free Volume in the Melt and How It Correlates with Experimental Glass Transition Temperatures: Results for a Large Set of Polymers by White, Ronald P, Lipson, Jane E. G

“…There is a continuing, strong interest in making connections between the polymeric glass transition (T g) and bulk properties. In this Letter we apply the…”
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