Method of improving membrane properties via reaction of diazonium compounds or precursors
US4888116A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 19, 1988 |
| Grant date | Dec 19, 1989 |
| Priority date | — |
| Expiry date | Dec 19, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2323/30
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of improving the properties of a reverse osmosis membrane having a polyamide discriminating layer containing residual aromatic primary amine groups is described. In this method, the polyamide discriminating layer of the membrane is treated with an aqueous solution of a reagent which reacts with primary amine groups to form diazonium salt groups or derivatives of diazonium salt groups. This method results in a membrane possessing improved chlorine resistance. When nitrous acid is employed as the reagent in the treatment, the water flux of the polyamide membrane is frequently increased with little or no effect on the salt rejection of the membrane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.