1. Mode of action of gas permeability membranes

It is the thin film that controls the selective passage of gas or vapor molecules. It is commonly accepted that the selectivity and permeability of gas permeability membranes result from the effects of solubility and diffusion of molecules in the membrane material. The permeability of the same molecule in various polymers can vary from 1 to 10 ⁶ , as can the permeability of various molecules in the same polymer. As a result, a large number of polymers can be used. In general, elastomers have higher permeabilities than glassy polymers but, on the other hand, their selectivity is lower. However, there are many exceptions. In the case of separating very different molecules, for example vapors and a gas, elastomers are therefore preferable to glassy polymers, as the permeabilities are very different. On the other hand, glassy polymers...