ABSTRACT
Among characterization spectroscopies, magnetic resonances are liable to produce specific analyses of bulk and interface of solid powders, fibers, or composites. The importance of nuclear magnetic resonance is well known in liquids for the determination of the structure and of the dynamic of molecules, Owing to the considerable progress of the technique, this powerful method is also applicable to solids. Silica exists in various forms which can be classified on the basis of four main features: crystal structure, dispersity, surface composition, and porosity. The structure of highly polymerized silicate species depends on the alkali metal cation, i.e., low pH silicate solutions have structurally different silicate species as a function of alkali metal hydroxide. The origin of such differences is due to the formation aminopropylsilyl grafted brush polymer on the surface. Ceramic composites, obtained by dispersing nano-scale particles of one constituent into larger particles of a second constituent, have shown such improvements in mechanical properties.
