Modified organosilicas for adsorption of some organic acids
Анотація
The chemical modification of silica surface by nitrogen-containing organic reagents (y-aminopropyltriethoxysilane, imidazole or N-vinyl-2-pyrroIidone) and also with hexamethyl disilazane and hydrocarbon oligomers was proposed for the enhancement of adsorptive capacity of silica in respect to mqnocarboxyiic and bile acids. The calculation of the content of protonated and deprotonated groups on the surface of synthesized organosilicas with distinguished basicity of functional groups was performed using the program GRFIT for the model of diffuse layer. The contribution of hydrophobic and electrostatic interactions to the adsorption of organic acids was revealed. It has been established that the maximum of organic acids adsorption coincides with the value of pH at which the curve of increasing concentration of anion of organic acid and the curve of decreasing concentration of protonated functional groups of aminopropyl silica are intercrossed.
Посилання
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