Preparation of Porous Aminopropylsilsesquioxane by a Nonhydrolytic Sol−Gel Method in Ionic Liquid Solvent

The synthesis of porous aminopropylsilsesquioxane (APSS) has been achieved with 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM+PF6-) ionic liquid (IL) as a template solvent by a nonhydrolytic sol−gel method of 3-aminopropyltrimethoxysilane under mild temperature. By the alteration of the amount of IL or the catalyst, the gels with various specific surface areas ranged from ∼600 to ∼1500 m2 g-1 were obtained after the remove of IL by calcination, and their N2 sorption isotherms were typical IV-like isotherms with H2 hysteresis. The average Battett−Jouner−Halenda pore diameters ranged from 3.2 to 5.6 nm. The results demonstrated that BMIM+PF6- was physically embodied in the silsesquioxane bulk instead of the chemical bonding. Silsesquioxane has promise in catalysis, biosensors, etc. This work would also provide a way for us to prepare a wide variety of materials by using IL as a template solvent.