Subnanoscale composite, N2-permselective membrane for the separation of volatile organic compounds
US5789024A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1996 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | May 15, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2323/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A composite membrane is disclosed which operates as a filter for liquids, solids and gases and combinations thereof, having high permeability for the filtrate, e.g., nitrogen passing therethrough, and high selectivity for matter retained thereby, e.g., volatile organic compounds, so that the N.sub.2 /VOC selectivity is at least about 50/1 or greater; prepared by a low pressure chemical vapor deposition process comprising: (a) providing as a first component thereof, a mesoporous membrane substrate having pore diameters greater than about 20 .ANG.; (b) contacting surfaces, including pore surfaces, of the membrane with at least two reactant gas streams in an opposing reactant geometry, wherein the smallest reactant gas molecule has a kinetic diameter intermediate in size between that of the matter retained by said filter and the filtrate passing therethrough; the reactant gases are capable upon reaction of depositing thereon as a second component thereof, a reaction product which by coating the surfaces, including pore surfaces of said mesoporous substrate, substantially reduces the pore diameters thereof, resulting in a substantially uniform microporous film having pore diameters in …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.