A kaolinite-methanol intercalated complex with inter-spacing of 1.0 nm was synthesized by washing kaolinite with hydrazine monohydrate, 10 mol aqueous solution of urea, and pure methanol successively. The complex was unstable at the beginning and under ambient conditions for 72 hrs or the temperature of 105℃ for 2 min, the inter-spacing reduced to 0.85 nm, and further to 0.79 nm under the temperature of 200℃. It remained unchanged even if the complex was put under the temperature of 300℃ for 24 hrs.
The change in inter-spacing under heat treatment and the IR spectra of the resultant 0.85 nm and 0.79 nm intercalates clearly showed presence of methanol in the interspace of the complex. Judging from the expansion value and the minimum diameter of a methanol molecular, only a single layer of the organic molecules was intercalated with a considerable amount of bonds (lower inter-spacing of the intercalates indicating higher extent to which methanol molecules were inserted). It was deduced that methyls were possibly inserted into hexagonal rings of silica tetrahedrons and hydroxyls into octahedrons. Perturbation and shift of infrared absorption bands attributed to hydroxyls in kaolinite structure suggested that interaction between methanol molecule and kaolinite was stronger in 0.79 nm intercalate than in 0.85 nm intercalate.