Optimization Of Thorium(?)ions Adsorption Onto A Modified ?-cyclodextrin Polyrotaxane Using Response Surface Methodology(RSM)

Cyclodextrin?CD?is a kind of cyclic annular glucose oligosaccharide.Generally,the crystals is formed by the end to end of6,7or 8 D-glucopyranose units.Called?,?,?-cyclodextrin.Among all of them,?-cyclodextrin??-CD?is widely used because of its rich in raw materials,low toxicity,cheap and easy to get.Otherwise,there are still many defects in natural cyclodextrins.Thus limited its application in industry.Consequently,in order to improve its performance chemical modification of natural cyclodextrins was considered.Supramolecular chemistry is a type of interdiscipline composed of chemistry,and also is one of the most important research fields developed in recent years.It can be said that the supramolecular chemistry as“beyond molecular chemistry”has become an important direction of scientific research.Supramolecular chemistry is a kind of generalized coordination chemistry.It's made up of two or more species in a certain way by intermolecular forces.Chosen bonding effects between the weak and covalent bonds as the molecular block,by the means of molecular identification,transportation and transformation.To formation of supramolecular or supramolecular devices with specific structures and functions.Among them,cyclodextrin as the second generation of host compounds,has become a hot topic in the field of supramecular chemistry attribute to its inherent biological and easy modification.In order to expand the application of cyclodextrin supramolecular system.In this paper,we mainly introduce the preparation of 6-OTs-?-CD by heterogeneous reaction.And then use its as a rotor by threading modified?-CD onto the polyether amine chains to get a novel polyrotaxanes.Then using this nanometer systems as a adsorbent.Optimized the adsorption process by response surface methodology,their adsorption properties were investigated.Work content were shown as following three aspects:1.The structural characteristics and development of cyclodextrins based on cyclodextrins are summarized.Besides,we introduced the new method of synthesis of different structures in detail.Meanwhile,we also briefly introduced the recent progress in the application of polyrotaxanes based on CD's in the field of smart materials,biological medicine and scaffold for tissue engineering.At the end of section,we summarized the problems existing in the scientific research or poly rotaxanes based on CD's and also the future of this field was analyzed.2.Under alkaline conditions,by the means of heterogeneous reaction,we successfully synthesized 6-OTs-?-CD,then used its as a rotor synthesis of a poly rotaxanes with 3,5-dinitrobenzoic as its end group,to give a novel polyrotaxane nanoparticle.After that,the crude products were analyzed by FTIR.Then,the quantitative analysis was performed by means of ¹HNMR and elemental analysis thus calculated the degree of polymerization and the contents of C,H,and N elements.According to the report,the method is simple,scientific and reasonable.3.The response surface methodology of BBD was employed to filtrate the influence factors of the adsorption process.Statistical analysis shown that:pH,initial Th?IV?concentration,adsorbent dosage and equilibrium time were four key factors of influence the yield.Therefore,a four factor and three level experiment was designed to investigate the interaction between the significant factors affecting the adsorption process.By analysis the data of fitting model experiment,the results shown that:all the single effect contribute obviously significant to the adsorption of Th?VI?.By analysis the variance?ANOVA?and correlation coefficients the data reveal that the predicted conformation is according with the experimental well.The optimal condition was as follow:pH=3.72,equilibrium time 35.4 min,initial adsorbate concentration 22.8mg.L^-1 and adsorbent dosage 30mg.Under the optimum condition adsorbing capacity of Th?IV?was reached 13.62 mg.g^-1.Adsorption data were modeled by Langmuir,Freundlich and Dubinin-Radusckevich?D-R?adsorption isotherms.Thermodynamic studies revealed that PR was an excellent sorbent material and the adsorption process was fitted the Langmuir single molecule isotherm adsorption model well.And then we fitted the thermodynamic data.In the process,?H⁰>0,?S⁰>0,?G⁰<0indicated that the adsorption behavior was a spontaneous endothermic process.This research hope to provide a useful reference for future treatment of waster-water.