The use of multinuclear solid state NMR for the characterization of siloxane-oxide hybrid nanocomposites

The objective of this paper is to review various solid state NMR techniques that have been, or can be used for the structural characterization of siloxane—oxide hybrid systems prepared by sol-gel process, and to discuss the type of information they provide, as well as their limitations. More precisely, this paper focuses on NMR techniques to probe and quantify the different types of oxo-bridges (M–O–M of oxide network, Si–O–Si of siloxane chains and Si–O–M siloxane–M x O y interface) in siloxane-oxide nanocomposites prepared through hydrolysis and condensation of organosilanes and M(OR) n alkoxides. In addition the influence of the functionality of the silicon alkoxides and the nature of the M x O y oxides on the extent of the Si-O-M interface will be examined.