Interlamellar Silylation of Montmorillonite with 3-Aminopropyltriethoxysilane

H-montmorillonite was modified by interlayer surface silylation using 3-aminopropyltriethoxysilane and dodecylamine in ethanol without a pre-swelling step. Dodecylamine acts as a gallery expander and silylation catalyst. The evaporation of ethanol from the dispersion yields well-ordered silylated montmorillonites with large basal spacing between 1.50 and 4.20 nm. Solid-state ²9Si CP MAS NMR of the silylated samples showed Q²\;and\;Q³ signals as well as T²\;and\;T³ signals. The increase in the relative intensity of Q³\;for\;Q² and the appearance of T²\;and\;T³ signals was attributed to the grafting of 3-aminopropyltriethoxysilane to the interlayer surface silanol groups.