Synthesis and properties of MCM-41 with polymerizable CADMA cationic surfactant

Abstract

The synthesis route of MCM-41 was modified by using a cationic surfactant different from the usual CTMABr (cetyltrimethylammonium bromide). This surfactant, cetylallyldimethylammonium bromide (CADMABr), differs from CTMABr by the substitution of a methyl group located in the hydrophilic head by a polymerizable allyl group. The CADMABr surfactant and the CADMA-MCM-41 hybrid silica were synthesized using different times. Formation of the surfactant was confirmed using elemental analysis (CHN),13C nuclear magnetic resonance (C-13 NMR), and small-angle X-ray scattering (SAXS) applied to the dispersions of different concentrations of the surfactants in water. The aqueous dispersions of CADMABr and the hybrid silicas were irradiated at different doses of gamma (gamma) radiation in order to obtain information about the polymerization of the surfactant. The hybrid silicas were characterized using X-ray diffraction (XRD) for phase identification, together with thermogravimetry (TGA), nitrogen physisorption, and scanning electron microscopy (SEM). The catalytic properties of the silicas were evaluated using the transesterification reaction of monoalcohols as a model for application in biodiesel manufacture. (C) 2016 Elsevier B.V. All rights reserved.