Preparation And Adsorption Properties Of Silica Surface Octylphenol Molecularly Imprinted Polymer

In this paper, using silica gel as the carrier, octylphenol as a template molecule, octylphenol molecularly imprinted polymers (MIPs) have been successfully prepared by sol-gel method. The reaction conditions were optimized by screening functional monomers, optimizing the ratio of the functional monomers and cross-linking agent and contrasting eluent concentration. The results of fourier transform infrared spectroscopy, scanning electron microscopy, thermal gravimetric analysis confirmed the successful preparation of MIPs; The adsorption kinetics experiment test shows MIPs have a good dynamic properties, in about18min to reach equilibrium. The maximum adsorption capacity of SiO2-MIPs is7.478mg·g-1, and3.214mg·g-1for SO2h-NIPs. The adsorption amount of MIPs is better than that of NIPs. The results of selective adsorption experiment show that the removal rate of MIPs for octylphenol was higher than phenol and bisphcnol A by40.0%and42.0%. The repetitive experiments show imprinted polymer have high repetition utilization. The deference of the removal rate between first and fifth experiment is only5.90%, indicating that it has good stability.SiO2-MIPs which has recognition of template molecule octylphenol has been synthesized by RAFT surface molecular imprinting technique. The successful preparation of MIPs further confirmed by means of Fourier transform infrared spectroscopy, scanning electron microscopy, thermal gravimetric analysis. The results of adsorption kinetics experiment show that the adsorption amount and the adsorption rate of MIPs has better than those of NIPs. The saturated adsorption capacity of SiO2-MIPs and SiO2-NIPs was6.82mg·g-1and2.92mg·g-1, respectively. Through the adsorption isotherm experimental analysis of SiO2-MIPs and SiO2-NIPs, in the whole concentration range, the adsorption amount of SiO2-MIPs is significantly greater than that of SiO2-NIPs. The adsorption amount increases with the increasing of the concentration of the template molecule, indicating that the SiO2-MIPs has a strong adsorption performance and the ability to identify octylphenol. The results of selective adsorption experiments show that the removal rate of SiO2-MIPs was76.8%, which is significantly higher than SiO2-NIPs. The removal rates of phenol and bisphcnol A were24.3%and21.4%. This result shows that SiO2-MIPs has a strong selective adsorption performance of the template molecule octylphenol. Removal rates of SiO2-NIPs to three competition molecules were similar (25.2%,23.1%,19.2%), indicating that SiO2-NIPs basically did not have selective adsorption properties of octylphenol molecular. In five repeat experiments, the removal rate of octylphenyl by the SiO2-RAFT-MIPs octylphenyl have a slight reduce.By comparing the experimental conclusions of sol-gel method and the RAFT method, we found that sol-gel method is relatively simple than RAFT method on the process and high degree of operation. And the adsorption amount of the sol-gel method to the template molecule is higher than the RAFT method. But the adsorption rate of RAFT method to template molecules faster than the sol-gel method, and have higher recycling rate, there are good prospects in practical applications.