| 摘要 |
The invention relates to a new microporous membrane having a purely inorganic composition based essentially on isometric silica particles with an acurately defined size distribution. The material has a high chemical and thermal stability and has, deposited as internal partition walls or ultrafine films on a surface of ceramic supports, molecular sieve properties. The membrane may be fabricated according to one of the following two processes: a) from sols obtained by acidification of a soluble silicate with a mineral acid, producing an asymmetric multilayer membrane when depositing said sols on a ceramic support, and b) by floculation of silica in the inside of a ceramic support, when contacting the support impregnated with a soluble silicate with a solution of a bivalent or trivalent metal salt, thereby producing a microporous partition wall by filling the porous volume of the support with microporous silica. |
