| 摘要 |
Microporous membranes with a porosity gradient from one surface to the other are prepd. by controlling the speed of neutralisation of an acidic soln contg. a polymer, e.g. polyamides, polyesters, etc; this is achieved by diffusion of the neutralising reagent, e.g NaOH, through the pores of the membrane in the course of its formation. The membranes are air and vapour permeable but liquid impermeable. |
