Preparation And Characterization Of Carbamazepine Imprinted Adsorbent By RAFT Surface Polymerization

Pharmaceutical and Personal Care Products（PPCPs）in natural water gradually shows biological toxicity.The removal of such contaminants by traditional water treatment processes has the disadvantages of low removal rate and susceptibility to interference.Molecularly imprinted polymers can achieve Targeted removal,the advantages of choosing strong adsorption in complex water environment can make up for this shortcoming.In this study,the traditional molecularly imprinted polymerization process cannot be controlled,which is easy to cause the adsorption sites to be covered and reduce the absorption performance.The epilepsy treatment drug carbamazepine（CBZ）in PPCPs is used as the target pollutant,and the Reversible Addition-Fragmentation Chain Transfer（RAFT）is dedicated to the development of carbamazepine imprinted adsorbent（R-MIP）with large adsorption capacity and fast adsorption rate.In this study,SiO₂ coated with magnetic nano-Fe₃O₄ was used as the carrier,and the R group CH₂Ph was grafted to the surface of the carrier by O-Si-C bond.The solid chain transfer agent benzyl dithiobenzoate was synthesized by the format reagent method.Based on the polymerization of Fe₃O₄ carrier molecularly imprinted polymer（R-MIP）.The characterization results show that R-MIP uses C-Si bonds to be evenly distributed on the surface of the support,and T-MIP directly covers the surface of Si O₂with agglomeration.R-MIP volume average particle size is 0.985μm,specific surface area is 4.57㎡/g,polymer layer thickness is 685-935nm,and can inhibit the magnetic dipole attraction of carrier particles and promote uniform dispersion of particles.The maximum adsorption amount of R-MIP measured by the isothermal adsorption experiment is 9.75mg/g,which is 4.3%higher than that of T-MIP prepared by traditional polymerization method.The adsorption factor K_R-MIP=3.92>K_T-MIP=3.20,It shows that there are more effective imprinting sites in R-MIP.But the adsorption capacity of non-imprinted polymer R-NIP is 2.48mg/g which is lower than that of T-NIP 2.92mg/g.The analysis shows that RAFT polymerization makes the surface of monomer R-NIP tightly bound,which reduces the specific surface area.The Freundilich model fits the T-MIP and T-NIP isotherm adsorption process better,and the Langmuir model is more in line with the R-MIP and R-NIP isotherm adsorption process.It shows that RAFT polymerization makes the adsorption sites evenly distributed on the surface,and the single layer adsorption is obvious.Scatchard analysis showed that the nature of the adsorption sites in R-MIP is basically the same,and the adsorption sites of the same type in T-MIP are mostly,but still not completely equivalent.The results of adsorption kinetics experiments show that the adsorption rate of R-MIP is higher,and the adsorption process fits well with the quasi-second-order kinetic model.The main role is chemical adsorption.When adding sorbent 1mg/m L to CBZ solution with a concentration of 10mg/L,R-MIP can adsorb 97.5%of carbamazepine molecules within15 minutes of R-MIP,and the removal rate of N-MIP is 93.4%at 20 minutes.In the adsorption selectivity experiment,the adsorption capacity of carbamazepine by R-MIP and T-MIP in the presence of oxcarbazepine and tap water decreased by at most 3.1%and 5.1%,respectively.The ability is stronger,and oxcarbazepine has less effect on the adsorption process,indicating that the recognition site of carbamazepine and the monomeric itaconic acid may exist on the carbon-carbon double bond to the nitrogen.After 5 repeated elution adsorption experiments,the adsorption capacity of R-MIP and T-MIP decreased by 1.27%and 1.30%,and there was no significant difference in the regeneration performance of the two materials.