Transparent ultralow-density silica aerogels prepared by a two-step sol-gel process

Conference · Sun Sep 01 00:00:00 EDT 1991

OSTI ID:6255022

Tillotson, T M; Hrubesh, L W

Conventional silica sol-gel chemistry is limited for the production of transparent ultralow-density aerogels because (1) gelation is either slow or unachievable, and (2) even when gelation is achieved, the large pore sizes result in loss of transparency for aerogels <.020 g/cc. We have developed a two-step sol-gel process that circumvents the limitations of the conventional process and allows the formation of ultralow-density gels in a matter of hours. we have found that the gel time is dependent on the catalyst concentration. After supercritical extraction, the aerogels are transparent, uncracked tiles with densities as low as .003 g/cc. 6 figs., 11 refs.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6255022
• Report Number(s): UCRL-JC-108615; CONF-910960--1; ON: DE92002661
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation &amp; Manufacture
ABSORPTION SPECTRA
ALKOXIDES
BULK DENSITY
CHALCOGENIDES
CHERENKOV COUNTERS
CHROMATOGRAPHY
CRYSTAL STRUCTURE
DENSITY
EVEN-ODD NUCLEI
GAS CHROMATOGRAPHY
GELATION
ISOTOPES
LIGHT NUCLEI
MASS SPECTROSCOPY
MATERIALS
MEASURING INSTRUMENTS
MICROSTRUCTURE
MINERALS
NMR SPECTRA
NUCLEI
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POROUS MATERIALS
RADIATION DETECTORS
SEPARATION PROCESSES
SILICA
SILICON 29
SILICON COMPOUNDS
SILICON ISOTOPES
SILICON OXIDES
SOL-GEL PROCESS
SPECTRA
SPECTROSCOPY
STABLE ISOTOPES