Modelling of the diffusion of gases through membranes of novel polyimides

When new, better polymeric materials are to be developed for use as gas separation membranes, knowledge of the underlying principles of the separation process is essential. Much research is spent on the elucidation of the mechanism by which gas molecules sorb into and move through a polymer. Models were developed to describe the macroscopic behavior of the polymer in gas separation processes. The most widely used is the dual mode sorption model. To gain further insight in the mechanism the microscopic behavior, i.e. at a molecular scale, has to be considered. This thesis deals with one aspect of this last topic: the diffusion of gases through the polymer matrix, viewed at a molecular scale.