Mesoporous silicas were synthesized via a surfactant-templated sol-gel route using castor oil as the templating agent under acidic medium. The resulting silicas were subsequently amine functionalized with 3-aminopropyltriethoxysilane (NH2-MTS), [3-(2-aminoethylamino)-propyl]trimethoxysilane (NN-MTS), and [3-(diethylamino)propyl]trimethoxysilane(DN-MTS) to introduce surface basicity. Surface physicochemical properties were characterized by field emission gun scanning electron microscopy (FEGSEM), nitrogen porosimetry, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and diffuse reflectance infrared fourier transform spectroscopy (DRIFTS). As-synthesised materials exhibit type IV adsorption-desorption isotherms characteristic of mesoporous structures. Clusters of spherical shaped materials were observed by FEGSEM, suggesting growth of silica occurs within colloidal dispersions. High-resolution N 1s XP spectra and DRIFT spectra confirmed the presence of amine groups in the organo-amine functionalised mesoporous silicas. The amine functionalised mesoporous silicas were active for the transesterification of tributyrin with methanol, with conversion found to increase from NH2-MTS< NN-MTS< DN-MTS.
Bibliographical noteThis article has been published in a revised form in RSC Advances [http://doi.org/10.1557/adv.2018.347]. This version is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works. © copyright holder.
Funding: Leverhulme Royal Society African Award and Mkwawa University College of Education (MUCE)