Robert Clifton Hopper

US Patent:

56860315, Nov 11, 1997

Filed:

Jan 5, 1995

Appl. No.:

8/368823

Inventors:

Paul R. Coronado - Livermore CA
John F. Poco - Livermore CA
Lawrence W. Hrubesh - Pleasanton CA
Robert W. Hopper - Danville CA

Assignee:

Regents of the University of California - Oakland CA

International Classification:

B29C 6500

US Classification:

264 401

Abstract:

An improved, rapid process is provided for making microporous and mesoporous materials, including aerogels and pre-ceramics. A gel or gel precursor is confined in a sealed vessel to prevent structural expansion of the gel during the heating process. This confinement allows the gelation and drying processes to be greatly accelerated, and significantly reduces the time required to produce a dried aerogel compared to conventional methods. Drying may be performed either by subcritical drying with a pressurized fluid to expel the liquid from the gel pores or by supercritical drying. The rates of heating and decompression are significantly higher than for conventional methods.