Preparation And Characterization Of Sol-Gel Molecularly Imprinted Polymer For Rhodamine B

Molecularly imprinted sol-gel technique is a method that leads the template molecules into inorganic network structures using sol-gel method to prepare molecular imprinted materials. Molecular imprinted polymers prepared by this technique have high specific selectivity, preferably a strong affinity and stability. This method has a wide range of applications for its simple to prepare and relatively mild reaction conditions.In this paper, a variety of titanium dioxide imprinted polymers were prepared under different conditions using the sol-gel method with Rhodamine B as the template molecule; and their structure and properties were also preliminarily studied. The main research content is as follows:Rhodamine B-based molecularly imprinted polymers were prepared under acidic conditions using the sol-gel method with Rhodamine B as a template molecule, butyl titanate as crosslinking agent, butyl titanate and TEOS hydrolysis as crosslinking agent, phenyl triethoxysilane as functional monomer and butyl titanate as crosslinking agent, respectively. The effects of the molar ratio of rhodamine B to butyl titanate, the reaction temperature, the amount of water and acid on the molecular imprinted polymer were investigated. The adsorption performance of Rhodamine B-based molecularly imprinted polymer in aqueous solution was investigated through static and dynamic adsorption experiments and compared with the non-imprinted polymers. The results showed that the adsorption performance of the molecularly imprinted polymer is stronger than the non-imprinted polymers. The selective adsorption experiments showed molecular imprinted polymer has specific recognition performance for the template. Under the same conditions, the molecularly imprinted polymer with phenyl triethoxy silane as functional monomer exhibited the best adsorption performance, and the adsorption performance of the molecularly imprinted polymer obtained by butyl titanate and ethyl orthosilicate is poorer. The infrared spectroscopy and thermogravimetric analysis showed that the polymer contained more hydroxyl and butyl titanate was almost totally hydrolyzed after eluting the molecularly imprinted polymers. However the molecularly imprinted polymer before elution and the non-imprinted polymers were found to retain unreacted oxygen and ethoxy groups. This suggests that the crosslinking agent is further complete reaction in the process of the removal of the template molecules. From the analysis of transmission electron microscope, molecular imprinted polymer gel has more loose pore micro-network crosslinking structures than non-imprinted polymer, which makes them has stronger adsorption performance. It shows that the improvement of the adsorption performance of the molecularly imprinted polymer using phenyl triethoxy silane as functional monomer should be associated with the selective recognition sites on functional monomer. The selective control experiment were also examined using Rhodamine 6G, the results showed that the molecularly imprinted polymer has better recognition ability for Rhodamine B. The regenerative capacity of molecularly imprinted polymer was also studied and the results indicate that the polymer has good reproducibility.