Metakaolin-nanosilver as biocide mullite precursor

Incorporation of silver nanoparticles enhances the biocide functionality of Ag supported kaolinite/metakaolite materials. In this regard, structural evolution of supports in the presence of silver nanoparticles is investigated. For this purpose, 27Al and 29Si magic-angle-spinning nuclear magnetic resonance spectroscopy was applied to investigate the bonding between silver nanoparticles and kaolinite/metakaolin materials. The incorporation of silver nanoparticles, following a chemical or thermal reduction, does not change the structure of kaolin, whereas in the case of metakaolin, a preferential interaction with tetrahedral sheets was observed and some stabilization of hexacoordinated aluminium is favoured.