METHOD OF MANUFACTURING THE SILICA NANOPOWDERS WITH BIOCIDAL PROPERTIES, ESPECIALLY FOR POLYMER COMPOSITES

摘要

Silica nanopowders with biocidal properties, especially for polymer composites, are produced by sol-gel method. The silica sol is produced from the aqueous mixture containing tetraalkoxysilane, in which alkoxy group contains from C1 to C4 carbon atoms, an alcohol or the mixture of aliphatic alcohols from C1 to C4, in the mole ratio of 1 : 5 to 1 : 35, in the presence of ammonium compound, used in an amount of from 0.001 to 0.05 mol per 1 mol of tetraalkoxysilane, with introducing, after thorough mixing of components, the silver salt in the form of aqueous solution in an amount from 0.02 to 1 mol per 1 mol of tetraalkoxysilane, and subsequently the aqueous solution of alkali metal hydroxide in an amount from 0.02 to 1 mol of hydroxide per 1 mol of tetraalkoxysilane. Silica nanopowders of the particle size of below 200 nm, contain silver nano- particles immobilized on silica, with stable physicochemical and biocidal properties.