Desalination reverse osmotic membranes and their preparation
US4111810A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1977 |
| Grant date | Sep 5, 1978 |
| Priority date | — |
| Expiry date | Mar 16, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L5/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Semipermeable membranes useful in reverse osmosis and a process of preparing them comprising deacetylating naturally occurring chitin to produce chitosan, making a film of chitosan salt from an acid diluted aqueous solution of the chitosan, converting the film of chitosan salt to a film of chitosan having free amino groups by neutralizing the acid groups, and then subjecting the film of chitosan to a chemical treatment with an organic acid, by which to convert the chitosan to the acetylated form, having a degree of acetylation from about 0.3 to 0.8, to produce the reverse osmotic membranes. The products have excellent chemical properties as well as mechanical strengths sufficient to withstand the pressure difference in the operating condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.