Hydrothermal interaction on amorphous silica spherules

Abstract

Opal has regularly stacked structure of hydrous amorphous silica spherules. In this study, hydrothermal synthesis of opal and infrared spectra analysis were carried out. In the run products at 100 degree C and 150 degree C within 30days, hydrous phase in silica is water molecule. With higher temperature and longer run durations, absorption peak derived from Si-OH compound is detected. Cementation of hydrous silica spherules may be faster than decomposition of Si-O compound in the low-temperature hydrothermal conditions.