摘要 |
<p>A gas separation member comprises a porous substrate, e.g., a membrane or a wall, and a polymer film deposited by plasma polymerization on the surface of the substrate and composed of at least two layers, i.e., a first layer contiguous with the substrate and a second layer superimposed on the first layer. The polymer film of the first layer possesses a uniform chemical composition or chemical structure in the direction of film thickness, while the polymer film of the second layer has a chemical composition or chemical structure which changes continuously or stepwise in the direction of film thickness. The gas separation member combines high gas separation factor and a high gas permeation rate, permitting separation of a specific gas in a concentrated form from a mixed gas. It also excels in weatherability.</p> |