Search Results - "Simmons, David S"

Understanding the Decreased Segmental Dynamics of Supported Thin Polymer Films Reported by Incoherent Neutron Scattering by Ye, Changhuai, Wiener, Clinton G, Tyagi, Madhusudan, Uhrig, David, Orski, Sara V, Soles, Christopher L, Vogt, Bryan D, Simmons, David S

“…Incoherent neutron scattering (INS) has commonly reported a suppression of segmental dynamics for supported thin polymer films as thickness is decreased, which…”
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An Emerging Unified View of Dynamic Interphases in Polymers by Simmons, David S.

“…The properties of nanostructured polymeric materials reflect the presence of a dynamic interphase in which polymer segmental dynamics, glass formation,…”
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Dynamical Correlations for Statistical Copolymers from High-Throughput Broad-Band Dielectric Spectroscopy by Zhang, Xiao, Zhao, Jing, Ye, Changhuai, Lai, Tzu-Yu, Snyder, Chad R, Karim, Alamgir, Cavicchi, Kevin A, Simmons, David S

“…Broad-band dielectric spectroscopy (BDS) provides a powerful method of characterizing relaxation dynamics in diverse materials. Here we describe and employ a…”
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Mobility gradients yield rubbery surfaces on top of polymer glasses by Hao, Zhiwei, Ghanekarade, Asieh, Zhu, Ningtao, Randazzo, Katelyn, Kawaguchi, Daisuke, Tanaka, Keiji, Wang, Xinping, Simmons, David S., Priestley, Rodney D., Zuo, Biao

“…Many emerging materials, such as ultrastable glasses 1 , 2 of interest for phone displays and OLED television screens, owe their properties to a gradient of…”
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Near-Substrate Gradients in Chain Relaxation and Viscosity in a Model Low-Molecular Weight Polymer by Rahman, Tamanna, Simmons, David S

“…Polymers in the nanoscale vicinity of interfaces can exhibit large alterations in dynamics and glass formation behavior. These changes are accompanied by…”
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Nature of dynamic gradients, glass formation, and collective effects in ultrathin freestanding films by Ghanekarade, Asieh, Phan, Anh D., Schweizer, Kenneth S., Simmons, David S.

“…Molecular, polymeric, colloidal, and other classes of liquids can exhibit very large, spatially heterogeneous alterations of their dynamics and glass…”
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Signature of collective elastic glass physics in surface-induced long-range tails in dynamical gradients by Ghanekarade, Asieh, Phan, Anh D., Schweizer, Kenneth S., Simmons, David S.

“…Understanding the underlying nature of dynamical correlations believed to drive the bulk glass transition is a long-standing problem. Here we show that the…”
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Glass Formation near Covalently Grafted Interfaces: Ionomers as a Model Case by Ruan, Dihui, Simmons, David S

“…In materials ranging from ionomers to semicrystalline polymers, the glass transitionthe central phenomenon determining the dynamic and mechanical behavior of…”
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Hierarchical Shape-Specified Model Polymer Nanoparticles via Copolymer Sequence Control by Tulsi, Davindra K, Simmons, David S

“…Nature employs copolymer sequence to realize exquisite control of molecular shape in nanostructures such as protein assemblies, membranes, and DNA complexes…”
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Interfacial Dynamic Length Scales in the Glass Transition of a Model Freestanding Polymer Film and Their Connection to Cooperative Motion by Lang, Ryan J, Simmons, David S

“…Nanoscale confinement alters the dynamics of glass-forming liquids in films of order 100 nm in thickness. A common hypothesis for the origin of this long range…”
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A Model for a Thermally Induced Polymer Coil-to-Globule Transition by Simmons, David S, Sanchez, Isaac C

“…A semiquantitative mean-field model for the thermally induced (heating-induced) polymer coil-to-globule transition (HCGT) is developed with no adjustable…”
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Neural-Network-Biased Genetic Algorithms for Materials Design: Evolutionary Algorithms That Learn by Patra, Tarak K, Meenakshisundaram, Venkatesh, Hung, Jui-Hsiang, Simmons, David S

“…Machine learning has the potential to dramatically accelerate high-throughput approaches to materials design, as demonstrated by successes in biomolecular…”
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Designing Sequence-Specific Copolymer Compatibilizers Using a Molecular-Dynamics-Simulation-Based Genetic Algorithm by Meenakshisundaram, Venkatesh, Hung, Jui-Hsiang, Patra, Tarak K, Simmons, David S

“…Compatibilizerssurfactant molecules designed to improve the stability of an interfaceare employed to enhance material properties in settings ranging from…”
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Roles of chain stiffness and segmental rattling in ionomer glass formation by Ruan, Dihui, Simmons, David S

“…Ionomers–polymers with bound ionic moieties—have received interest for their exceptional properties including high toughness and ion conductivity. One of the…”
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Design Rules for Highly Conductive Polymeric Ionic Liquids from Molecular Dynamics Simulations by Cheng, Yizi, Yang, Junhong, Hung, Jui-Hsiang, Patra, Tarak K, Simmons, David S

“…Polymeric ionic liquids (PILs) are of considerable interest as next-generation battery materials due to their potential to combine the solid-state stability of…”
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Do String-like Cooperative Motions Predict Relaxation Times in Glass-Forming Liquids? by Hung, Jui-Hsiang, Simmons, David S

“…The Adam–Gibbs theory of glass formation posits that the growth in the activation barrier of fragile liquids on cooling emerges from a loss of configurational…”
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Heterogeneous Rouse Model Predicts Polymer Chain Translational Normal Mode Decoupling by Hung, Jui-Hsiang, Mangalara, Jayachandra Hari, Simmons, David S

“…It has been known for 50 years that polymers exhibit chain normal mode decoupling upon approach to the glass transition, with chain dynamics exhibiting a…”
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Mixed equilibrium/nonequilibrium effects govern surface mobility in polymer glasses by Xu, Jianquan, Ghanekarade, Asieh, Li, Li, Zhu, Huifeng, Yuan, Hailin, Yan, Jinsong, Simmons, David S, Tsui, Ophelia K C, Wang, Xinping

“…Using angle-resolved X-ray photoelectron spectroscopy, sum-frequency generation vibrational spectroscopy, contact angle measurements, and molecular dynamics…”
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Tuning Polymer Glass Formation Behavior and Mechanical Properties with Oligomeric Diluents of Varying Stiffness by Mangalara, Jayachandra Hari, Simmons, David S

“…Small-molecule diluents are important tools in the control of polymers’ glass formation, transport, and mechanical properties. While recent work has indicated…”
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Temperature-Independent Rescaling of the Local Activation Barrier Drives Free Surface Nanoconfinement Effects on Segmental-Scale Translational Dynamics near T g by Diaz-Vela, Daniel, Hung, Jui-Hsiang, Simmons, David S

“…Near-interface alterations in dynamics and glass formation behavior have been the subject of extensive study for the past two decades, both because of their…”
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