CL-20分子印迹聚合物微球的制备及吸附性能

Preparation and Recognition Property of CL-20 Molecularly Imprinted Polymer Microspheres

利用分子印迹技术,在模板分子六硝基六氮杂异伍兹烷(CL-20)、功能单体丙烯酰胺(AM)、交联剂三羟甲基丙烷三甲基丙烯酸酯(TRIM)的摩尔比为1∶7∶20,反应温度为60℃的条件下,采用沉淀聚合法制备了粒径约为1μm的CL-20分子印迹聚合物微球(CL-20-MIP)。用UV光谱,SEM对其进行了性能测试,研究了CL-20-MIP的吸附和识别性能。结果表明,CL-20与AM之间存在相互作用,所得产物为规则的球形。在1 mmol·L-1的CL-20/乙醇溶液中,CL-20-MIP和非印迹聚合物(NMIP)对CL-20的平衡吸附量分别为14.02 mg·g-1和6.77 mg·g-1;吸附过程由伪二级动力学模型和Freundlich方程描述。选择性吸附实验表明,CL-20-MIP对CL-20具有特异性吸附,对竞争吸附物RDX,TNT的吸附量分别为6.98 mg·g-1和8.46 mg·g-1。

Molecularly imprinted polymer （MIP） microspheres were prepared via precipitation polymerization with hexanitro- hexaazaisowurtzitane（CL-20） as template acrylamide as functional monomer trimethylolpropane triacrylate as crosslinking agent~ acetonitrile as solvent and porogen and 2,2-azobisisobutyronitrile （AIBN） as initiatives using molecularly imprinted tech- nology （MIT）. The optimum synthetic conditions were obtained as follow： the molar ratio of the template, functional monomer and crosslinking agent was1 ： 7 ： 20 and the experiment temperature was 60℃ The synthesized polymer microspheres are regu- larly spheres and their diameter is about 1μm. The interaction between the CL-20 and the function monomer was determined by UV-visible adsorption spectrums and the microstructures of CL-20/MIP and NMIP were observed by scanning electron microscope （SEM）. Results show that the CL-20 interacts with the functional monomers~ and CL-20/MIP microspheres have good sphericity and are independent to each others while a certain degree of reunion phenomenon is found in the NMIP microspheres. The recog- nition capability studied by equilibrium binding experiment show that the equilibrium binding capacity of the microspheres is 14.02 mg · g-1 in CL-20/alcohol solution with the concentration of 0.4 mmol· L-1s while the binding capacity of NMIP is 6.77 mg· g-1. The amounts of RDX and TNT adsorbed by CL-20-MIP in selective binding experiments is 6.98 mg· g-1 and 8.46 mg · g-1, respectively indicating MIP possesse recognition property of CL-20. The adsorption thermodynamics shows that CL-20-MIP and NMIP have good adsorption property and are accord with Freundlich adsorption isotherm. Studies of adsorption kinetics show that the adsorption of CL-20-MIP can simulate by pseudo-first order and pseudo-second order kinetics models but the latter equation is better.