抄録
A novel modeling technique, which combines molecular simulations with a permeation theory, for a prediction of
gas permeability through zeolite membranes is proposed. Permeability of hydrocarbons and inorganic gases
through an MFI-type silicalite membrane was systematically predicted by using this technique. The estimated permeability were in agreement with the experimental data, although they were an order of magnitude larger than those
previously reported in experimental studies. This diversity is because of the effect of the grain boundary that was
examined by further studies using PFG-NMR and molecular simulation. Permeation by various single gases (H2, He,
Ne, Ar, O2, N2, CO2, CH4) through different density amorphous silica membrane models has been investigated using
the grand canonical ensemble molecular dynamics (GCMD). Molecular trajectory analysis clearly reveals the occurring molecular sieving and that He has many permeation paths in the membrane in addition to the path of H2. The
transition boundary of the temperature dependence of gas permeability through molecular sieving membranes was
also investigated by GCMD, using membrane models having cylindrical pores with a pose size range of 0.3 - 0.5 nm.
Activated transport was found when the pore size of the membrane became smaller than 1.3 times that of the molecular diameter of the permeating species. Consequently, molecular modeling techniques are approved as powerful
approach for the investigation of permeation mechanism and prediction of gas permeability in ceramic membranes.
