| abstract |
A method is described for sealing pinholes and covering imperfections passing through a multi-layer membrane composite to be employed for conducting a gas separation process. The particular breaches through such composites that this invention is intended to deal with are those caused by the unavoidable presence of particles smaller than about 3000 A. By this method an additional ultrathin membrane of very flexible, permeable polymer material is applied over the outer surface of the membrane composite. |