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A range of thiol-silica composites were prepared using cashew nut shell liquid (CNSL) or one of its phenolic constituents, cardanol, as templates. The procedure involved formation of a CNSL or cardanol emulsion in a water-ethanol system into which (3-mercaptopropyl)-trimethoxysilane and tetraethyl orthosilicate were simultaneously added at various ratios. The reaction mixture was aged at room temperature for 18 h followed by a Soxhlet extraction of the template and drying. The materials were characterized by diffuse reflectance Fourier transform infrared, nitrogen physisorption, scanning electron microscopy and acid titration. Results indicated that indeed the thiol-silica composites were successfully prepared, with thiol group loadings ranging from 1.6-2.5 mmol/g. The materials were tested for lead(II) adsorption, and results showed that they had maximum adsorption capacities up to 66.7 mg/g, depending on the thiol group loading and type of template used in preparing the adsorbent. DOI: http://dx.doi.org/10.4314/bcse.v28i3.5

A neutral amine templating route was used to prepare dimethylaminopropyl-derivatised micelle templated silicas with various loadings. The resultant materials were characterised by various techniques and were also screened as catalysts in model Michael addition reactions. Results obtained show that materials with surface areas and organic group loading as high as 800 m2g-1 and 3.4 mmol per g of silica, respectively, are obtainable. The materials show moderate to high catalytic activity as well as selectivity in a range of substrates. The activities and selectivities,however, are affected by catalyst loading and type of solvent.

Polyamine-silica hybrids were prepared by a one-pot sol-gel method via a neutral amine templating route. At low loadings (ca. 1 mmol organic group per g of silica) the resultant materials displayed properties typical of M41S-type materials, namely, high surface area (typically 600 m2 g-1) and controlled porosity with an average pore diameter of 3.6 nm. However, the materials were amorphous at loading above 1.2 mmol organic group per g of silica. The materials were used as heterogeneous base catalysts in the epoxidation of electron deficient olefins. The yields of the epoxide product ranged between 52% and 76%, depending on the loading of the catalytic group.

Bull. Chem. Soc. Ethiop. 1996, 10(1), 21-32.