One-step synthesis and solvent-induced exfoliation of hybrid organic-inorganic phyllosilicate-like materials

A room-temperature sol-gel-based process was used to produce by direct synthesis talc-like organosilicates having hexadecyl or aminopropyl groups pending in the interlayer space. Thermal analyses, Fourier transform infrared and 13C/29Si solid-state nuclear magnetic resonance spectroscopies confirmed the presence of organic moieties bonded to the inorganic network. Exfoliation of these organoclays in polar solvents such as water for the positively charged magnesium phyllo(aminopropyl)silicate, and in low polar solvents such as toluene and chloroform for hydrophobic magnesium phyllo(hexadecyl)silicate, was investigated by TEM. The ability of these layered magnesium organosilicates to exfoliate in appropriate solvents was exploited for the preparation of transparent self-supporting films and ordered macroporous networks using by latex colloidal crystal templates.