In situ studies of the sol-gel synthesis of materials

The use of in situ methods to study the synthesis of materials from sol-gel precursors is reviewed, with particular emphasis on the formation of crystalline phases from solid gel precursors and the crystallization of zeolitic materials from solution under hydrothermal conditions. A wide range of studies that have been performed under nonambient conditions are discussed under the following headings: X-ray and neutron methods, spectroscopic and resonance methods, and imaging methods. Some current trends and future developments are assessed.