Permeable membranes for enhanced gas separation
US4881954A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1987 |
| Grant date | Nov 21, 1989 |
| Priority date | — |
| Expiry date | Jul 31, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D69/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Composite membranes are prepared by depositing a separation layer on an asymmetric support layer. The separation layer has a selectivity equal to or greater than that of the material of the asymmetric support layer for a desired gas separation. The support layer is desirably produced in non-asymmetric form, and exposed to an elevated temperature approaching the glass transition temperature of the support layer material under non-swelling conditions to modify the structure thereof to create asymmetry therein, before or after the deposition of the separation layer, and to increase its compaction resistance and collapse pressure. Such desirable properties are conveniently achieved on a repeatable basis, enhancing the uniformity and reliability of the treated support layer and of composite membranes produced therefrom, for use in gas separation operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.