Aggregates in silica based matrices

Abstract

Embedding nano-aggregates in silica based supports may be a usefull method to control their size and protect them against degradation. Some examples are given to illustrate the potentiality of this method. Metal aggregates can be obtained on reducing an oxide or salt dispersed in a silica gel or by ion implantation in dense silica layers. In both cases the particles size can be controlled by the conditions of elaboration. Organic nano-crystals such as fullerenes and polydiacetylenes can be also incorporated in mesoporous silica. In this case, the size of the crystals is controled by the size of the pores.