Carbon nanotubes (CNTs) have been proposed as excellent materials for the construction of new, precisely tailored ultrafiltration membranes and as promising fibres for the construction of new, stronger composite materials. In this paper classical molecular dynamics simulations are used to investigate the potential use of CNTs in these applications. Functional groups have been covalently attache...

Porous media are of considerable interest in a very diverse range of activities. They comprise a wide variety of substances—plastics, ceramics, cements, clays, rocks, porous glasses, carbons, silica gels, zeolites, the recently emerging metal–organic frameworks and coordination polymers, and many more. Even biological tissues may share many features of porous media. Depending on the given natur...

We consider the motion of a particle in a periodic two dimensional flow perturbed by small (molecular) diffusion. The flow is generated by a divergence free zero mean vector field. The long time behavior corresponds to the behavior of the homogenized process that is diffusion process with the constant diffusion matrix (effective diffusivity). We obtain the asymptotics of the effective diffusivi...

In previous chapters we considered the processes of advection and molecular diffusion and have seen some example problems with so called “turbulent diffusion” coefficients, where we use the same governing equations, but with larger diffusion (mixing) coefficients. In natural rivers, a host of processes lead to a non-uniform velocity field, which allows mixing to occur much faster than by molecu...

Relaxation in glass-forming liquids occurs as a multi-stage hierarchical process involving cooperative molecular motion. First, there is a "fast" relaxation process dominated by the inertial motion of the molecules whose amplitude grows upon heating, followed by a longer time α-relaxation process involving both large-scale diffusive molecular motion and momentum diffusion. Our molecular dynamic...

Diffusion ordering separates overlapping spectra in protein mixtures of different molecular size.

In this paper, the effects of different aluminum to silicon ratios in silicate chains of calcium silicate hydrates (C-S-H) are evaluated on the diffusion coefficient of chloride ions by molecular dynamics method. Tobermorite is a crystalline phase that is used for studying C-S-H properties in nano scale, because of its analogous chemical composition to C-S-H. Aluminum incorporation in C-S-H and...

Molecular diffusion in the brain extracellular space (ECS) is an important determinant of neural function. We developed a brain surface photobleaching method to measure the diffusion of fluorescently labeled macromolecules in the ECS of the cerebral cortex. The ECS in mouse brain was labeled by exposure of the intact dura to fluorescein-dextrans (M(r) 4, 70, and 500 kDa). Fluorescein-dextran di...

Transportation of amino acids throughout the body is an essential mechanism to support life processes. phenomena such as diffusion, viscosity, etc., in aqueous medium are useful understand their inter- and intra-molecular interactions. In this work, we performed classical molecular dynamics simulation study transportation properties γ-aminobutyric acid (GABA) environment. Self-diffusion coeffic...