Preparation And Adsorption Of Surface Molecularly Imprinted Polymers For Carbaryl

With the specific adsorption ability, molecular imprinted polymers(MIPs) can adsorb amino acid ester pesticides in fruits and vegetables. In the preparation of molecularly imprinted polymer, bulk polymerization was commonly used, but it had cumbersome preparation process, entrapped active site and slower transfer rate. In this paper, the surface molecularly imprinted polymers (SMIPs) were prepared by using MIT and the coating method and then films of the SMIPs were prepared. This preparatory work was for the molecular imprinting sensor with lower detection limit and faster detection time.In the experiment, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA) and BET surface determination were used to characterize the SMIPs, and the type of functional monomers, molar ratio of functional monomers/molecularly imprinted, cross-linker, coating amount of the surface silica gel and adsorption conditions factors were analyzed. The results showed: that MAA as functional monomer, function monomer/molecularly imprinted molar ratio of 4:1, the self-assembly temperature was 20 ℃, cross-linking was 1.5mmol, coating amount of the surface silica gel was 0.25mmol,adsorption time was 12h,adsorption temperature is 25 ℃,sample concentration was 10mg/L, The maximum adsorption capacity of SMIPs was 0.58mg/g,with pore size was lnm, the specific surface area was 82.395m2/g. For the preparation of the molecular imprinting sensor, the amount of polyvinyl chloride and the amount of SMIPs were investigated. The experimental results show that: polyvinyl chloride was 15mg, SMIPs was 20mg, the molecularly imprinted film has highest adsorption capacity,and the maximum adsorption capacity was 0.18mg/g.At the end of the adsorption process of equilibrium adsorption isotherm and kinetic model isotherm were used to fit the results of the adsorption processes, indicating that the adsorption process was a single molecular layer adsorption, and the adsorption fit the Langmuir adsorption isotherm, linear correlation coefficient R2=0.9987. At the kinetic model isotherm, the result indicated that the adsorption process belongs to the pseudo-second-order model. At the same time,the Scatchard curve also was used to fit the results of the adsorption processes, it can be drawn that SMIPs has two types of binding sites, the other of binding sites was specific binding sites: KD,1=0.004mol/mL, Qmax,1=1.0129 mg/g ; another was non-specific binding site: KD,2=0.009 mol/mL, Qmax,2=1.3043 mmol/g。...