Study on QPVA/TEOS hybrid anion membrane functionalized with quaternary ammonium groups for adsorption of Rhodamine B from aqueous solutions

Quaternized poly(vinyl alcohol)/tetraethoxysilane hybrid membranes were prepared and their adsorbability for Rhodamine B from aqueous solution was investigated. Experimental parameters, which will affect Rhodamine B sorption, such as tetraethoxysilane contents, pH, contact time, initial concentration and temperature were studied. The research results revealed that adsorption effect of Rhodamine B was enhanced by the formation of organic-inorganic hybrid structure and the grafting of quaternary ammonium groups. The fitting result of kinetic data was revealed that the pseudo-second-order model best described the adsorption of Rhodamine B. The equilibrium data were fitted by three isotherm models, and the Temkin model gave the best fit result based on the adsorption equilibrium data. Also, the adsorption free energy showed that the mechanism of Rhodamine B adsorption onto the membrane was chemisorption. Thermodynamic parameters calculation results revealed that the adsorption process of Rhodamine B onto the hybrid membrane was endothermic and spontaneous. Moreover, the hybrid membrane was successfully utilized for successive five cycles for the adsorption-desorption of Rhodamine B.