Polymer glass formation: Role of activation free energy, configurational entropy, and collective motion

WS Xu, JF Douglas, ZY Sun - Macromolecules, 2021 - ACS Publications
We provide a perspective on polymer glass formation, with an emphasis on models in which
the fluid entropy and collective particle motion dominate the theoretical description and data …

Fast dynamics in a model metallic glass-forming material

H Zhang, X Wang, HB Yu, JF Douglas - The Journal of Chemical …, 2021 - pubs.aip.org
We investigate the fast β-and Johari–Goldstein (JG) β-relaxation processes, along with the
elastic scattering response of glass-forming (GF) liquids and the boson peak, in a simulated …

The interfacial zone in thin polymer films and around nanoparticles in polymer nanocomposites

W Zhang, H Emamy, BA Pazmiño Betancourt… - The Journal of …, 2019 - pubs.aip.org
We perform coarse-grained simulations of model unentangled polymer materials to quantify
the range over which interfaces alter the structure and dynamics in the vicinity of the …

When crystals flow

CH Tu, M Steinhart, R Berger, M Kappl, HJ Butt… - Science …, 2023 - science.org
Semicrystalline polymers are solids that are supposed to flow only above their melting
temperature. By using confinement within nanoscopic cylindrical pores, we show that a …

The initiation of shear band formation in deformed metallic glasses from soft localized domains

X Wang, H Zhang, JF Douglas - The Journal of Chemical Physics, 2021 - pubs.aip.org
It has long been thought that shear band (SB) formation in amorphous solids initiates from
relatively “soft” regions in the material in which large-scale non-affine deformations become …

Activation free energy gradient controls interfacial mobility gradient in thin polymer films

W Zhang, FW Starr, JF Douglas - The Journal of Chemical Physics, 2021 - pubs.aip.org
We examine the mobility gradient in the interfacial region of substrate-supported polymer
films using molecular dynamics simulations and interpret these gradients within the string …

Universal nature of dynamic heterogeneity in glass-forming liquids: A comparative study of metallic and polymeric glass-forming liquids

X Wang, WS Xu, H Zhang, JF Douglas - The Journal of chemical …, 2019 - pubs.aip.org
Glass-formation is a ubiquitous phenomenon that is often observed in a broad class of
materials ranging from biological matter to commonly encountered synthetic polymer, as …

Superionic UO2: A model anharmonic crystalline material

H Zhang, X Wang, A Chremos… - The Journal of chemical …, 2019 - pubs.aip.org
Crystalline materials at elevated temperatures and pressures can exhibit properties more
reminiscent of simple liquids than ideal crystalline materials. Superionic crystalline materials …

Investigation of the temperature dependence of activation volume in glass-forming polymer melts under variable pressure conditions

WS Xu, JF Douglas, W Xia, X Xu - Macromolecules, 2020 - ACS Publications
Motivated by empirical observations suggesting that changes in the activation volume Δ V#
upon varying temperature (T), determined from the pressure (P) dependence of the …

Localization model description of the interfacial dynamics of crystalline Cu and Cu64Zr36 metallic glass films

G Mahmud, H Zhang, JF Douglas - The Journal of Chemical Physics, 2020 - pubs.aip.org
Recent studies of structural relaxation in Cu–Zr metallic glass materials having a range of
compositions and over a wide range of temperatures and in crystalline UO 2 under …