MODELING OF THE REACTION-PHASE INTERACTION OF GAMMA-AMINOPROPYLTRIETHOXYSILANE WITH SILICA

The coating formed in the reaction phase of the modification of silica with gamma-aminopropyltriethoxysilane was modelled using the freeze s ampling method with a classical N-determination. The formation of a mo nolayer coating in the reaction phase is confirmed. Within the selecte d region of silane : silica ratio, the monolayer capacity value was de termined to be 1.02 mmol g-1 on dehydrated silica gel and 0.63 mmol g- 1 on the dehydroxylated substrate. The obtained monolayer structure is described and related to the specific surface area of the substrate u sed. APTS molecules are distributed over the silica surface with each molecule covering 64 angstrom2.