MicroGel® is a unique, highly porous xero-gel silica formed using sol-gel techniques. The starting materials used are designed per guidance from molecular dynamic calculations, and are made up of mixed alkali silicates rather than normally used single alkali silicates that are gelled with appropriate mineral acid at controlled temperature and time.

The gel is aged and heated in a controlled manner to achieve desired high-pore-volume silicas, which are further washed per needs of space environment stability to remove unwanted species,

and to control impurities. The gel attains unique performance properties through energetic filling of unwanted species, and helps in the passivation performance.

The high porosity achieved is due to the use of mixed alkali silicate starting material, and uniquely allows protonation of pigment surfaces while providing a reproducible pigment coating that renders passivation to pigment surfaces, and provides protection from a degrading space environment at high temperatures.

This work was done by M.S. Deshapnde of AMSENG for Glenn Research Center. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp  under the Materials category.

Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Innovative Partnerships Office, Attn: Steve Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. Refer to LEW-18508-1.