Integrity-testable wet-dry-reversible ultrafiltration membranes and method for testing same
US5685991A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1995 |
| Grant date | Nov 11, 1997 |
| Priority date | — |
| Expiry date | Oct 12, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2015/086
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention provides for the first time ultrafiltration/diafiltration membranes that are capable of excluding 0.02 .mu.m diameter, monodisperse, latex particles and are capable of being dried without loss of such ultrafiltration properties. A rapid, reliable method for integrity testing membranes also has now been discovered. The test has particular applicability to ultrafiltration membranes, although it may also be used for testing microfiltration membranes as well. In accordance with the method, referred to as the K.sub.UF method, the membrane to be tested is first thoroughly wetted with a wetting liquid that is capable of fully wetting the membrane; a displacing liquid is placed in contact with one side of the wetted membrane and increasing pressure is then applied to said displacing liquid; and the flow rate through said membrane is measured as a function of the applied pressure; wherein the displacing liquid is substantially insoluble in the wetting liquid and the interfacial tension between the two liquids is about 10.0 dynes/cm or less. A plot of the flow rate of liquid, per unit area of the membrane, through the membrane as a function of applied pressure can be ma…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.