Preparing Micron Anion Imprinted Microspheres Based On Inverted Suspension Polymerization And Studying On The Properties Of Ion Recognition

With the rapid development of Chinese economic, water pollution has become a serious problem restricting the rapid development of China’s economy, affecting people’s lives. It affects people’s health and make severe damage to the environment, while resulting in ecological balance disorders. For example, the emissions of wastewater on the industrial of textiles, metallurgy, pesticide, electroplating, coking can cause multi-system, multi-organ damage to life. And the phosphorust in urban sewage will cause serious eutrophication, rapid propagation of algae and plankton, decline of dissolved oxygen in water, deterioration of water quality, result in massive death of classes of aerobic organisms, and it will bring lots of adverse effects to human if they drink this kind of water for a long time. Therefore, it is very urgent to develop new technologies and materials actively for removing pollutants from water.In this study, a new ion imprinting method that graft polymerization carried out simultaneously with the molecularly imprinted in the method of inverse suspension polymerization is found. The anionic gel imprinted microspheres can remove electronegative compounds in the water with high efficiency. The results have potential applications in the protection of water environment.The crosslinking copolymerization (CP) of acryloxyethyltrimethyl ammonium chloride (DAC) N,N’-methylene bisacrylamide (MBA) was performed via inverse suspension polymerization method, and200-300μm, m gel microspheres CPDAC were prepared. Cyclohexane was used as dispersion medium and Span-60was used as dispersant. The effects of main factors on the balling performance and grain diameter of the gel microspheres were researched. The gel microspheres were characterized. The adsorption (anion exchange) characteristic of CPDAC was studied. The results showed that in order to prepare CPDAC, the dispersion phase (water) must be added in the manner of dropwise adding, Span-60is a suitable dispersant, and the grain diameter of the gel microspheres decreases with increasing the amount of Span-60. The volume ratio of oil phase to water phase can not be smaller than2:1, the grain diameter of the gel microspheres decreases with increasing the volume ratio. The agitating rate can not lower than250r/min, the grain diameter decreases with up the rate. By right of the strong ion exchange action and electrostatic interaction, CPDAC can produce strong adsorption to four anionic species, SCN、NO3-、HPO42-and SO42-, and their adsorption capacities are167,172,127.2and144mg/g, respectively. The adsorption capacity decreases with increasing temperature.Micron-sized thiocyanate anion-imprinted microspheres were prepared successfully with inverse suspension polymerization method. The inverse suspension polymerization system was constituted by oil phase, in which cyclohexane was used as dispersion medium and Span-60was used as dispersant, and water phase, in which the cationic monomer of acryloxy ethyl trimethyl ammonium chloride (DAC), the crosslinker N,N’-Methylene bisacrylamide (MBA) and the template SCN-anion were dissolved in water. The crosslinking copolymerization of DAC in water-in-oil droplets was carried out, and SCN" anion-imprinted microspheres (IIPMs) of about200μm were obtained. The ion recognition selectivity and binding property were investigated in depth with monovalent anions, NO3-and I-, as contrast anions. The investigation results show that in water-in-oil droplets, the cationic monomer DAC combines with SCN-anion by right of strong electrostatic interaction, so that while DAC produces crosslinking polymerization, SCN" anion-imprinting is realized. The prepared IIPMs possess very strong binding ability (a binding capacity of3.3mmol/g,192mg/g) and special recognition selectivity. The IIPMs can selectively recognize and bind SCN-anion from a mixed ion solution, and relative to NO3-and I-ions, the coefficients of selectivity of IIPMs are3.24and6.78, respectively. The IIPMs still have excellent reusability. The adsorption capacity of imprinted materials can approximate94%of the saturation adsorption capacity of new imprinted materials at the fifth of reuse times.Lastly, hydrophosphate anion-imprinted microspheres were prepared in the same method that used before. The anion-imprinted microspherescan get after the remove of template. The ion recognition selectivity and binding property were investigated in depth with monovalent anions, MnO4-and SO42-, as contrast anions. The investigation results show that in water-in-oil droplets, the cationic monomer DAC combines with HPO42-anion by right of strong electrostatic interaction, so that while DAC produces crosslinking polymerization, HPO42-anion-imprinting is realized. The prepared IIPMs possess very strong binding ability (a binding capacity of1.51mmol/g,145mg/g) and special recognition selectivity. The IIPMs can selectively recognize and bind HPO42-anion from a mixed ion solution, and relative to MnO4-and SO42-ions, the coefficients of selectivity of IIPMs are2.14and2.71, respectively. The IIPMs still have excellent reusability. The adsorption capacity of imprinted materials can approximate90%of the saturation adsorption capacity of new imprinted materials at the sixth of reuse times.