Fig. 6. Important reactions with functional silanes for surface modification. Reactions mostly proceed in a solvent, water is typically excluded, because otherwise the silanization agents are hydrolyzed in an uncontrolled manner away from the surface. (a) Functional monochlorosilane, (b) functional monoalkoxysilane, (c) functional disilazane, silicon atoms in the disilazane can also be bridged via R-groups, and (d) functional trialkoxysilane, here attachment via one, two, or three siloxane bonds to the surface is possible, moreover, functional silanes can crosslink with themselves and thus produce oligomeric/polymeric surface-bound species. The example shown has one alkoxy group left for further crosslinking. As in general silicate chemistry, silicate species avoid edge or face sharing tetrahedra linked to each other.