Related papers: Molecular Dynamics Simulations of NMR Relaxation a…
The hydrogen phase diagram has a number of unusual features which are generally well reproduced by density functional calculations. Unfortunately, these calculations fail to provide good physical insights into why those features occur. In…
Motivated by recent observations that non-concatenated ring polymers in their dense solution exhibit a glass-like dynamics, we propose a free volume description of the motion of such rings based on the notion of topological volume. We first…
Soft-mode turbulence (SMT) is the spatiotemporal chaos observed in homeotropically aligned nematic liquid crystals, where non-thermal fluctuations are induced by nonlinear coupling between the Nambu-Goldstone and convective modes. The net…
Nanoscale confinement of molecules in a fluid can result in enhanced viscosity, local fluidic order, or collective motion. Confinement also affects ion transport and/or the rate and equilibrium concentration in a chemical reaction, all of…
We use 2H NMR stimulated-echo spectroscopy to measure two-time correlation functions characterizing the polymer segmental motion in polymer electrolytes PPO-LiClO4 near the glass transition temperature Tg. To investigate effects of the salt…
Self-diffusion and NMR relaxation of ethylammonium (EA) cations were studied in the protic ionic liquid ethylammonium nitrate (EAN) confined between parallel polar glass plates separated by a few um as a function of time after placement in…
Molecular dynamics simulations are utilized to study the melting transition in pentane (C5H12) and heptane (C7H16), physisorbed onto the basal plane of graphite at near-monolayer coverages. Through use of the newest, optimized version of…
We use molecular dynamics simulations to investigate the displacement of a simple butterfly-like molecular motor inside nanopores of various radii filled with a viscous medium. The medium is modeled with a versatile potential that may be…
The molecular mobility of propane and propylene has been studied by 2H NMR method. The activation barriers of diffusion determined from the spin relaxation analysis are in a good agreement with the values obtained by Liu et al. (EC3H8 = 38…
Introducing nanorods into a polymeric matrix can enhance the physical and mechanical properties of the resulting material. In this paper, we focus on understanding the dispersion and orientation patterns of nanorods in an unentangled…
We analyze the displacements of the particles of a glass-forming molecular liquid perpendicular to a confining solid surface, using extensive molecular dynamics simulations with atomistic models. In the vicinity of an attractive surface,…
We present a method to probe molecular and nanoparticle diffusion within thin, solvated polymer coatings. The device exploits the confinement with well-defined geometry that forms at the interface between a planar and a hemi-spherical…
First nonlinear gyrokinetic simulations of microtearing modes in the core of a MAST case are performed on two surfaces of the high-collisionality discharge used in Valovi\v{c} et al. Nucl. Fusion 51.7 (2011) to obtain the favorable energy…
Monte Carlo simulations are used to study the behavior of two polymers under confinement in a cylindrical tube. Each polymer is modeled as a chain of hard spheres. We measure the free energy of the system, F, as a function of the distance…
Reptation theory has been highly successful in explaining the unusual material properties of entangled polymer solutions. It reduces the complex many-body dynamics to a single-polymer description where each polymer is envisaged to be…
We use dynamic nuclear polarization (DNP) enhanced nuclear magnetic resonance (NMR) at liquid helium temperatures to directly detect hydrogen attached to the surface of silicon microparticles. The proton NMR spectrum from a dry sample of…
Dynamics of regio-regulated Poly(4-methylthiazole-2,5-diyl) [HH-P4MeTz] was inves tigated by solid-state 1H, 2D, 13C NMR spectroscopies, and differential scanning calorimetry(DSC) measurements. DSC, 2D quadrupolar echo NMR, 13C…
We use molecular dynamics simulations to study the behavior of a compressible Lennard-Jones fluid in simple shear flow in a two-dimensional nanochannel. The system is equilibrated in the fluid phase close to the triple point at which gas,…
We investigate the process of biopolymer translocation through a narrow pore using a multiscale approach which explicitly accounts for the hydrodynamic interactions of the molecule with the surrounding solvent. The simulations confirm that…
We present computer simulations of a simple bead-spring model for polymer melts with intramolecular barriers. By systematically tuning the strength of the barriers, we investigate their role on the glass transition. Dynamic observables are…