Abstract

AbstractThe sol-gel base catalysed hydrolytic polycondensations of tetramethoxysilane (TMOS) were studied in the presence of quaternary ammonium chloride substituted polyhedral oligosilsesquioxanes (POSSes): octa{3-[(2- hydroxyethyl)dimethylammonio]propyl chloride}octasilsesquioxane or octa[3-(noctyldimethylammonio) propyl chloride]octasilsesquioxane. Small amounts of these POSSes added to the sol-gel system markedly affected the morphology of the silica gel polycondensation products. The morphology was highly dependent on the POSS concentration. Amorphous mesoporous silica gels were obtained showing a high porosity and the surface area up to 615 m2g-1. Most of gels had a fairly large average pore diameters, 4-11 nm and pore volume 0.4-1.3 cm3g-1. TMOS having inserted hexamethyltrisiloxane chain, 1,1,1,7-tetramethoxyhexamethyltetra siloxane, (TMOSD3) in the mixture with TMOS was also used as the monomer in the sol-gel polycondensation; but obtained gels showed a low porosity.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.