Abstract
The permeability, diffusivity and solubility of gas in rubbery polymer membrane have been studied using a pseudononequilibrium molecular dynamics (MD) simulation. We employed the ‘permeation simulation’ composed of gas/membrane/vacuum, and another is the ‘sorption simulation’ composed of gas/membrane/gas. In both models, the adoption of the virtual liquid molecules, which have no interaction with the gas molecules, allowed the control of the system pressure that led to the quantitative transport simulation analogous to the real experiments. The permeation coefficient, the mutual diffusion coefficient and solubility coefficient of oxygen in poly(dimethyl siloxane) at 298 K were directly obtained from the present MD simulation using the two simulation models. These calculated parameters were comparable to the experimental values. The present method may be useful for obtaining information on the microscopic aspects of the transport process of small molecules both at the interface and inside the rubbery polymer membrane.
