Kenji Yasuoka

Molecular dynamics computer simulation was carried out to investigate the dynamics of vapor phase homogeneous nucleation at the triple point temperature under supersaturation ratio 6.8 for a Lennard-Jones fluid. To control the system temperature, the 5000 target particles were mixed with 5000 soft-core carrier gas particles. The observed nucleation rate is seven orders of magnitude larger than prediction of a classical nucleation theory. The kinetically defined critical nucleus size, at which th

Homogeneous nucleation process in the vapor phase of water is investigated with a molecular dynamics computer simulation at 350 K under supersaturation ratio 7.3. Using a method similar to Lennard-Jones fluid (Part I), the nucleation rate is three orders of magnitude smaller than prediction of a classical nucleation theory. The kinetically defined critical nucleus size is 30–45, much larger than the thermodynamically defined value of 1.0 estimated with the classical theory. Free energy of cluste

Molecular dynamics computer simulations were carried out to investigate the dynamics of evaporation and condensation for argon at the temperature of 80 and 100 K. From the decrease of the survival probability of vapor molecules, the ratio of self reflection to collision is estimated to be 12%–15%, only weakly dependent on the temperature. This suggests that argon vapor molecules are in the condition of almost complete capture, and the condensation is considered to be a barrierless process. The t

We investigate translocation dynamics of a vesicle cell under collision with a Janus or a homogeneous hydrophobic/hydrophilic nanoparticle. To this end, we perform dissipative particle dynamics simulation by setting the nanoparticle with different initial velocities, different chemical patterns of the surface for the nanoparticle, and different orientations (for the Janus nanoparticle). Particular attention is given to translocation dynamics, in-cell water discharge, and the late-stage morpholog

Molecular dynamics simulations of nucleation of Lennard-Jones vapor confined in a slit pore have been performed. The walls of the slit pore are structureless walls; each wall interacts with vapor molecules via Lennard-Jones 9–3 potential. The rate of nucleation in the steady state is determined by analyzing time evolution of the cluster size distribution. At the same vapor density and temperature, the nucleation rate in the slit pore is higher than in the homogeneous vapor [K. Yasuoka and M. Mat

Methanol is used in various applications, such as fuel for transportation vehicles, fuel cells, and in chemical industrial processes. Conventionally, separation of methanol from aqueous solution is by distillation. However, this method consumes a large amount of energy; hence development of a new method is needed. In this work, molecular dynamics simulations are performed to investigate the effect of an electric field on water–methanol separation by carbon nanotubes (CNTs) with diameters of 0.81