Conference information: Proceedings (online) of the 10th Brazilian Meeting on Adsorption
Abstract: A series of silica xerogels, bearing Rhodamine B as the template were synthesized by distinct sol-gel routes, namely: acid-catalyzed, basic catalyzed, acid, followed by basic catalysis (two steps) hydrolytic routes and a FeCl3 catalyzed non-hydrolytic route. The extraction method (thermal, Soxhlet, water washing, ultrassound) was also evaluated. The resulting xerogels were characterized by porosimetry by the adsorption/desorption of nitrogen (BET method), Fourier-transform infrared spectroscopy (FTIR) and zeta potential. The preparation route did affect the textural properties of the materials. The best extraction capacity was achieved by acid and two-steps routes. Acid route showed the highest selectivity factor (2.5) between Rhodamine B and Rhodamine 6G. The best imprinting factor was achieved by the non-hydrolytic route. Competitive adsorptions were also carried out, resulting in an imprinting factor about 2. Apparently, the selectivity appears to be dictated by the shape generated through encapsulation and extraction rather than the magnitude of the surface area.
Template and target information: Rhodamine B
Author keywords: sol-gel, molecular imprinting, silica