Novel polyamide reverse osmosis membranes
US4769148A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1987 |
| Grant date | Sep 6, 1988 |
| Priority date | — |
| Expiry date | Nov 18, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D71/56
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An improved composite polyamide membrane and methods of making the membrane are described. This improved membrane is prepared using a cationic polymeric wetting agent in an aqueous solution containing a polyfunctional amine reactant which is interfacially polymerized with an acyl halide to form a thin film polyamide discriminating layer on a microporous support. Alternatively, the wetting agent can be applied directly to the substrate and the interfacial polymerization can occur on said treated substrate. The resulting membrane exhibits an unexpected combination of high water flux, high rejection of divalent anion salts, variable sodium chloride rejection and good caustic resistance at low operating pressures. In one embodiment of this invention, a porous substrate is first treated with an aqueous piperazine solution containing a copolymer of vinylbenzyl dimethyl sulfonium chloride and methacrylic acid and then the coated microporous support is contacted with trimesoyl chloride in an organic solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.