Process for manufacturing membranes for osmotic separation
US4147622A · kind A · utility
16Cited by
3References
40Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 18, 1977 |
| Grant date | Apr 3, 1979 |
| Priority date | — |
| Expiry date | Mar 18, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A20/131
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An asymmetrical permselective cellulose triacetate membrane has outstanding properties for desalination of seawater by reverse osmosis. It is made by casting a solvent solution of the cellulose triacetate in a solvent mixture of at least 40% acetone, a solvent for the triacetate and a swelling agent for the triacetate. The swelling agent, preferably formamide, must be added as the last component of the solution. After exposing the cast solution to evaporation for 2-90 seconds, it is precipitated in cold water, and then optionally tempered at 50.degree.-100.degree. C. in water which may contain a modifying agent, and dried.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.