| 摘要 |
<p>PURPOSE:To improve permeation velocity of a semipermeable membrane for a condensible gas without impairing a permselectivity coefft. of the membrane by constituting the semipermeable membrane of at least one roughened surface, wherein the surface area of the roughened surface is >=5 times of a projected area of the surface. CONSTITUTION:A semipermeable membrane to be used for gas separation is constituted to have at least one roughened surface and the surface area of the roughened surface is regulated to be >=5 times of a projected area of the surface. Preferred surface roughness of the semipermeable membrane is 0.5-100mum, particularly 1-50mum. The roughened surface area is regulated to be >=5 times, pref. >=10 times basing on the projected area of the surface by regulating the number of fine unevennesses to 10<3>-10<15> per 1cm<2> of the area of the membrane. The semipermeable membrane is constituted pref. of a high molecular film capable of contg. dissolved condensible gas such as steam, ammonia. The semipermeable membrane obtd. by this method has improved permeation velocity without impairing permselective coeffts. for condensible gases.</p> |
