CONICET | Buscador de Institutos y Recursos Humanos

The TiO2 organoclays are potential adsorbents for aqueous pollutants and subsequently they could favor the photocatalysis of them. For this reason, the study of their surface and textural characteristics is important for the improvement of those processes. In this work, TiO2 pillared organoclays, were the surfactant (hexa decyltrimethilammonium bromide) was introduce post-pillaring or during the pillaring process were studied. The effect of the use of different hydrolysis acids and different surfactants ratios was investigated. The clays were characterized by thermogravimetric analysis, infrared spectroscopy and nitrogen sorptometry. Also, it was measured the concentration of bromide by precipitation titration to determine the amount of surfactant adsorbed as ionic pair, it was determined the wettability of the samples by contact angle measures with water and their cationic exchange capacity (CEC). It was found that the highest adsorption capacity post-pillaring of the surfactant is near to 0.5 times the CEC of the original pillared clay, independently of the amount of surfactant offered. An increment in the amount of the surfactant offered only increase the ratio adsorbed as ionic pair. In these samples, the CEC measured after the adsorption is between 0.26 and 0.47 times the original CEC. In the level of textural properties, in all the samples it is observed a decrease in the total pore volume and the BET surface. The surface hydrophobicity of the samples with post-pillaring adsorption is higher than in those with co-adsorption. In conclusion, it was demonstrated that the incorporation of surfactant modifies the surface and textural properties of the material in different extent in accordance with the incorporation stage and the amount of surfactant used.