Patent · US Expired

Method for preparation of porous glass film

US4521236A · kind A · utility

9Cited by
4References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 2, 1983
Grant dateJun 4, 1985
Priority date
Expiry dateSep 2, 2003

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC03C13/005
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

There is provided a method for preparation of porous glass films, preferably in the form of a hollow filament, comprising heating glass films, formed from sodium borosilicate glass having a composition which can be phase-separated by heat-treatment into a soft phase easily eluted with a hot acid solution and a hard phase not easily eluted with the same solution, to separate the glass phase into the two phases and then subjecting the glass film to plasma etching in an atmosphere containing gaseous fluorine-containing compound(s) before or after acid elution of the soft phase. The thus obtained porous glass films have a uniform pore diameter and smooth surfaces and can be used as a variety of separating membranes.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.