Self-assembled sulfonated block copolymer semipermeable membrane and uses therefor
US6579948B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2000 |
| Grant date | Jun 17, 2003 |
| Priority date | — |
| Expiry date | Nov 22, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249959
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A semipermeable membrane that is capable of remaining flexible at a temperature of at least −60° C. is selective to liquid penetrants depending on the size and polarity of the penetrants, and more specifically, the membrane has sufficient selectivity so as to be capable of allowing water to diffuse therethrough at a higher rate than virtually all organic liquids having a molecular weight higher than that of methanol. The semipermeable membrane, which is produced from an unsulfonated block copolymer having polystyrene and polyisobutylene segments, includes a sulfonated block copolymer including poly (styrene-co-styrene sulfonic acid) segments and polyisobutylene segments. Prior to modification by sulfonation, the unsulfonated polystyrene and polyisobutylene block copolymer includes polystyrene monomer in an amount of from 5% to 90% by weight of the total unsulfonated block copolymer. After modification, from 1 to 70 mole % of the polystyrene monomer in the unsulfonated polystyrene and polyisobutylene block copolymer is converted to styrene sulfonic acid in the sulfonated block copolymer. By virtue of the semipermeable membrane's excellent transport and mechanical propertie…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.