Surface and texture properties of mesoporous silica materials modified by silicon-organic compounds containing quaternary amino groups for their application in base-catalyzed reactions

Abstract

The synthesis of organic-inorganic composite materials (OICM) was performed by the surface modification of mesoporous silica material (MM) type MCM-41 by N-((trimethoxysilyl)propyl)-N,N,N-trimethylammonium chloride (TMTMAC). The application of diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, X-ray diffraction (XRD), N2 adsorption/desorption and thermogravimetric analysis (TGA) showed that the distribution of grafted TMTMAC strongly depended on polarity and nature of solvent used for grafting. For water a clustering of TMTMAC resulted in a pore blockage. Methanol was identified to be the most suitable solvent to obtain a low loading and more homogeneous distribution of aminosilanes. Thermogravimetric analysis showed the composites were thermally stable up to 180 °C.