Method of producing inorganic aerogels under subcritical conditions

US6017505A · kind A · utility

Assignee

• BASF SE

Inventors

• Bernd Ziegler · Ludwigshafen, DE
• Thomas Gerber · Papendorf, DE

Key dates

• Filing date: Apr 14, 1998
• Grant date: Jan 25, 2000
• Expiry date: Apr 14, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/54
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Preparation of inorganic aerogels based on oxides of the metals magnesium, aluminum, silicon, tin, lanthanum, titanium, zirconium, chromium and/or thorium by producing a hydrogel in a sol/gel process, replacing the water in the hydrogel by an organic solvent, and drying the solvent-moist gel, takes place by conducting the drying step by exposing the solvent-moist gel to an ambient temperature which is above the boiling temperature of the solvent and at a pressure which is below the supercritical pressure of the solvent in such a way that the solvent within the gel is heated up very rapidly and evaporates.