Preparation of porous substrates having well defined morphology
US4954381A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1988 |
| Grant date | Sep 4, 1990 |
| Priority date | — |
| Expiry date | Mar 21, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2987
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A membrane of defined pore structure and controlled pore diameter and a method of preparing the membrane which comprises dispersing in a water soluble polymer solution (A) an organic polymer solution (B), the water-soluble polymer solution (A) being a non-solvent for the polymer solution (B), to form micro-spherical droplets of the polymer solution (A) which are enveloped by a solid phase consisting of a coagulated or cross-linked polymer solution (B); evenly casting the dispersion on a flat surface; and evaporating the solvent for the polymer solution (B) to form a microporous membrane comprised of the polymer (B), the porosity, pore size, and void volume of the microporous membrane being a function of the polymer (A) concentration, the microsphere dimensions and the temperature and evaporation rate. The water-soluble polymer (A) is selected from polyethyleneimine, gelatin, polyvinyl-pyrrolidone, polyvinyl pyridinium halide, polyacrylic acid, polyhydroxyethylmethacrylate (HEMA), dextran, or polyvinyl acetate. The continuous phase polymer (B) is selected from a brominated polyphenylene oxide, polyphenylene oxide, polyacetic acid, polystyrene, polyglycol acrylate (PGA), polymethylme…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.