Univ Tokyo, Inst Phys, Grad Sch Arts & Sci, Meguro Ku, Tokyo 1538902, Japan
; Inst High Energy Phys, Nat Lab, Beijing 100080, Peoples R China
The effect of heat treatment on silica aerogel has been studied by a positron age-momentum correlation technique and infrared measurement. A difference was observed between the momentum distributions of the electrons on the first layers of the silica aerogel grain surfaces and the electrons in the grains in an as-supplied sample, but not in the sample heat treated at 800 degreesC. A large change in the S parameter for the momentum distribution of the electrons on the first layer occurs around 200 degreesC. This change correlates well with that of the infrared spectra, which show oxidation of the methoxyl groups at temperatures above around 200 degreesC. This correlation reveals that those groups are mainly located on the first layer of the silica grains.
Suzuki, N,Oonishi, T,Hyodo, T,et al. Study of silica aerogel grain surfaces by using a positron age-momentum correlation technique[J]. APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING,2002,74(6):791-795.
Suzuki, N,Oonishi, T,Hyodo, T,&Chang, T.(2002).Study of silica aerogel grain surfaces by using a positron age-momentum correlation technique.APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING,74(6),791-795.
Suzuki, N,et al."Study of silica aerogel grain surfaces by using a positron age-momentum correlation technique".APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING 74.6(2002):791-795.