3. Coupling friction and surface reactivity – tribochemistry

A remarkable property of silicate tribology is the importance of tribochemical effects. This is hardly surprising, considering the singular behavior of silicates in solid state chemistry and their considerable role in sol-gel processes . Two properties explain these peculiarities. Firstly, the valence number of the silicon atom is low (N = 4), and secondly, the reactivity of the Si-O iono-covalent bond is moderate. It is therefore relatively easy to control the hydrolysis and condensation of silanes by the liquid route, in a hydroalcoholic medium. A range of methods have been developed by solid-state chemists to obtain materials with a variety...