Preparation And Application Of Dendrimers Grafted Polymer Liquid Chromatography Separation Materials

With continues improvement in the preparation technology of chromatographic separation materials,their preparation and modification methods have gradually developed into an independent discipline.The synthesis of novel stationary phase and adsorbents with modified methods has important academic value and practical significance.Dendrimers are a kind of novel macromolecules with perfect three-dimensional structure.Their repeated internal structure units and large amounts of terminal functional groups are very suitable for the modification of chromatographic separation materials.In this work,different types of grafted liquid chromatography separation materials were prepared by means of organic polymer microspheres modified with poly(amide-amine)(PAMAM)dendrimers.The obtained separation materials have a large number of surface functional groups and controllable adsorption properties,which subsequently impart good adsorption and separation effects on glyphosate,aniline compounds and various anionic substancesIn chapter 1,the basic situation,properties,structural characteristics and preparation methods of dendrimers were reviewed,and the applications of the PAMAM dendrimers in other fields are briefly introduced.At the same time,the application of PAMAM dendrimers in liquid chromatography separation materials and the preliminary progress were discussed in detail,which provided new ideas for the fabrication of PAMAM dendrimers grafted polymer chromatographic separation materials.In chapter 2,polystyrene-divinylbenzene-glycidyl methacrylate(PS-GMA)microspheres and PAMAM dendrimers were prepared respectively.And the grafted polymer beads with the controllable number of surface functional groups were prepared,by grafting different generations PAMAM on the surface of PS-GMA microspheres The structure and properties were characterized,providing a theoretical basis for application of the PAMAM dendrimers grafted polymer beads in chromatographic separation.In chapter 3,the prepared dendrimers grafted beads were used for glyphosate adsorption in solution.Through the batch adsorption experiments,influence from various experimental factors on adsorption efficiency was explored.According to the results,the adsorption mechanism,kinetic equation and the isothermal adsorption model were discussed.Finally,the adsorbent was applied for glyphosate adsorption in water samples,which shortened the adsorption time obviously.In chapter 4,the prepared dendrimers grafted polymer beads were used as stationary phase of high performance liquid chromatography(HPLC)and used for rapid separation of aniline compounds.The separation mechanism,as well as the influence of polymer monomer contents and dendrimer generations on the separation effect,were explored.Finally,by direct separation and column switching methods,the homemade stationary phase was successfully applied for the determination of aniline compounds in different samples.In chapter 5,1,4-butanediol diglycidyl ether(BDDE)reagent was applied for further quaternization of prepared dendrimers grafted polymer beads,and anion exchangers with the great number of quaternary ammonium groups on the surface were obtained.The influence of polymer monomer contents and dendrimer generations on the ion exchange capacity were explored.The prepared ion exchangers have good separation effect on common anions and carbohydrates.In chapter 6,graphene oxide(GO)materials were hybridized with polymer matrix to prepare organic-inorganic composited material.After then,PAMAM dendrimers and BDDE regent were used for further modification of the composited substrates.According to the experimental results,GO hybridization not only improved the separation performance of anion exchanger but also increased the thermal stability of the polymer matrix.