Study On Preparation For Two Different Kinds Of Tribenuron-methyl Molecularly Imprinted Polymer Membrances And Their Performances

Molecular imprinting is a method that can prepare polymer material with predetermined selectivity towords guest molecules. This technique camed from Fischer's lock-and-key hypothesis and Pauling's antibody-forming theory. Taking advantage of the shape, size, functional groups corresponding to the template molecule inside the molecularly imprinted polymer, the selectively recognization for the tribenuron-methyl was realized through for template molecule. Molecularly imprinted polymer not only has specific recognization like enzyme and antibody, but also has other advantages like specific chemical and physical stability, long working life, simple preparation methods. Consequently, it was widely applied such as chromatographic stationary phase, enzyme-micing catalysis, solid phase extraction (SPE), drug delivery system(DDS), and sensing technology.Molecularly imprinted membranes combine the advantages of molecular imprinting and membrane separation. It also has specialty such as simple operation, less energy, short reaction time, clean, uncontaminated, high stability, good mechanical properties, high permselectivity and recognization capability compared with biological membrane.The hazard of pesticide residual has aroused more and more people's attention. In the year 2006, the beginning of Eleventh Five-year Plan, molecular imprinting technique as a key program applied in the field of pesticide detection has been supported by National 863 Plan. At present it is a urgent need for food security to research and improve rapid detection method, and also a common desire for governments and people.In this paper, N,O-bismethacryloyl ethanolamine was synthesized as crosslinking monomer, then the binding mechanism between N,O-bismethacryloyl ethanolamine and tribenuron-methyl in methanol was studied with UV-visible spectrophotometer. Based on this study, using tribenuron-methyl as template molecule, molecularly imprinted membrane was prepared. Then, morphologies of the resultant polymeric membrane or the control membrane were visualized with scanning electron microscopy (SEM), and the imprinting factor was also detected. The membrane permselectivity for tribenuron-methyl, thifensulfuron-methyl and chlorimuron-ethyl was tested with separate experiments and competitive diffusion experiments. These results showed that the molecularly imprinted membrane exhibited higher transport selectivity for the template molecule tribenuron-methyl.Then, molecularly imprinted nanowire membrane was prepared through surface-initiated atom transfer radical polymerization (ATRP), and the morphologies of the prepared molecularly imprinted nanowire membrane and the control membrane was observed. The adsorption isotherm of the molecularly imprinted nanowire membrane toward the template molecule was drawed, and the associated property of the molecularly imprinted nanowire membrane toward tribenuron-methyl was confirmed using Scatchard equation. The membrane permselectivity for tribenuron-methyl, thifensulfuron-methyl, chlorimuron-ethyl and BCIA was tested with separate experiments and competitive diffusion experiments. These results showed that the olecularly imprinted membrane exhibited higher transport selectivity for the template molecule tribenuron-methyl.In the process of preparing molecularly imprinted membrane, the preparation procedure was simplified greatly by ignoring the optimum ratio of functional monomer/cross-linker, and the optimum ratio of functional monomer/template. Utilization of NOBE alone often provides molecularly imprinted polymers with higher affinity toward templates than those of incorporating a functional monomer. This selective identification feature will help to develop sensor technique in rapid detection of tribenuron-methyl residual, and it is of some guiding significance for settling rapid detection method of pesticide residual.