Interlayer esterification of layered silicic acid-alcohol nanostructured materials derived from alkoxytrichlorosilane

Layered silicic acid-organic nanohybrid materials consisting of long-chain alkoxy groups attached to thin silica layers have been prepared via esterification of a layered silicic acid-alcohol nanostructured material derived from hexadecoxytrichlorosilane (C₁₆H₃₃OSiCl₃). The esterification reaction was performed by heating the layered composite. The detailed characterization of the product heated at 80°C revealed that the interlayer alcohol molecules partly (∼50%) reacted with the interlayer surface silanol groups to form alkoxy groups. Unreacted alcohol molecules were removed by tetrahydrofuran (THF) treatment to form a novel alkoxylated layered silica material. This product retains its structure up to 120°C and has a higher stability in organic solvents if compared with the layered silicic acid-alcohol nanocomposite before esterification, whose structure collapsed over 100°C. Furthermore, various alcohols can be adsorbed into the esterified nanohybrid with the expansion of the interlayer spacing.