AN INFRARED STUDY OF THE REACTION OF OCTADECYLTRICHLOROSILANE WITH SILICA

The reaction of octadecyltrichlorosilane with a high surface area fumed silica was studied by infrared spectroscopy. We have found that the amount of water adsorbed on the surface was critical for adsorption to occur. We have shown that there is no direct reaction of octadecyltrichlorosilane (OTS) with the surface hydroxyl groups of adsorption with the first water layer bound to the surface of a fumed silica. Adsorption of the OTS does occur with the subsequent layers of water.