A novel one-step synthesis of mesostructured silica-pillared clay with highly ordered gallery organic-inorganic hybrid frame

A new class of organic-inorganic hybrid mesostructured silica-pillared clay (HSPC) has been prepared through the surfactant directed assembly of organosilica in the galleries of montmorillonite. The surfactant templates were removed from the pores by solvent-extraction. The products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), nitrogen adsorption-desorption measurements, solid-state Si-29 and C-13 NMR, and Fourier-transform infrared (FT-IR) spectra. XRD patterns indicated a regular interstratifications of the clay layers for HSPCs. Depending on loading of phenyl groups, HSPCs had BET surface areas of 395-602m(2) g(-1), pore volumes of 0.34-0.79cm(3)g(-1), and the framework pore sizes in the supermicropore to small mesopore range (1.3-2.6 nm). HSPCs were hydrophobic and acidic. The number of silanol groups on the surface of HSPC materials has been titrated by a surface reaction with hexamethyldisilazane, followed by quantification of the liberated NH3. Based on this method extracted HPCHs have high silanol numbers, a very important feature with respect to the amount of catalytic sites that can eventually be grafted onto the surface. (C) 2011 Elsevier B.V. All rights reserved.