Preparation Of β-cyclodextrin Ramification And Its Application In Adsorption

Cyclodextrins are cyclic oligomas linked by six D-glucopyranose head-to-tail, nowa-days, the emphasis on the environmental issues are increasing around the world, and as asafe、green、non-pollution complex, cyclodextrins get the attention of people generally.Cyclodextrins have some defects such as poor mechanical in the application,but thereare some active hydroxy outside the molecule cavity,the active hydroxy can be crosslinkedto many functional groups, and the cyclodextrins cavities are shielded by the C-H bond toform hydrophobic area, the hydrophobic cavities can include some hydrophobic perssads,these special structures lay the foundation of cyclodextrins’application in the industriesareas of food、medical treatment、cosmetics、textiles and environmental protection. In thewaste water conduction,the traditional adsorve gathering methods are Liquid-Liquidextraction,Liquid membrane extraction,Ion exchange,stratography,Solid-phase extractionand so on,the methods have some defects such as high cost、poor adsorb effect and havesecondary pollution, and cyclodextrins application is limited by the defects to a certaindegree,so producting simple,high effective and lowly priced adsorbent is necessary. AsThioureas chelate resin, Thioureas compounds are applied to the study of ion adsorptionwidely, Sym-Diphenyl-Thiourea has two hydrophobic benzene rings, and the benzene ringscan be included by the cavity of β-cyclodextrin to form host and guest inclusion complex,and this is a high-efficiency new ion adsorption which is recyclable.So, in thisarticle,6-Deoxytosyl-β-cyclodextrin is synthetized,then Sym-Diphenyl-Thiourea isincludedbythe6-Deoxytosyl-β-cyclodextrin,the inclusion can adsorb radioactive elementsuch as thorium and aranium,the main five assignments are as follows:1. The research report and review concluded had studied the β-cyclodextrins inprofiles, the β-cyclodextrins derivatives in food、medical treatment、cosmetics、textiles andenvironmental protection,a and the feasibility analysis had made on the topic proposingand the direction of the research subjects. 2.6-deoxy-tosyl-β-cyclodextrin was prepared by the reaction of β-cyclodextrin andSym-Diphenyl-Thiourea,and the compound was characterized by means of HNMR andIR,the analysis results indicate the synthetic method was reasonable and scientific.3. In the6-OTs-β-CD molecul,the canivy is retained, Sym-Diphenyl-Thiourea hastwo hydrophobic benzene rings,and then,the hydrophobic benzene rings were included bythe cavity by the method of solution-stirring. Sym-Diphenyl-Thiourea itself containsimidogen and thiourea groups which can chelate metal ions.When the benzene rings wereincluded by the cavity,the imidogen and tuiourea groups were exposed sufficiently,theability of adsorbing metal ions was improved,so,the inclusion complex6-OTs-β-CD/Sym-Diph-enyl-Thiourea was a high-efficiency and new-style adsorbent. The inclusioncomplex was characterized by IR and comprehensive thermal analysis spectrum,thesemethods were employed to determine the new adsorbent was prepared successfully.4. The study contrastively analyzed Sym-Diphenyl-Thiourea and inclusion complex inthe adsorption to Th4+and (UO2)2+,and explored the influence of different factor,like pH、time and adsorption addition to adsorbing capacity.The experimental results were asfollows:At the room temperature,pH=4, shaking for10min and the sorbent mass was0.025g, the adsorbing capacity to Th4+was27.46mg/g, and the adsorption rate was up to91.5%.Scanning electron microscope(SEM) and FT-IR were employed to characterize themorphology of the material; PH=4，shaking for20min and the sorbent mass was0.03g,the adsorption capacity to （UO2）2+was33.39mg/g. The infection on the adsorption of（UO2）2+by interfering irons was unconspicuous, and the adsorbent can be recycled bynitric acid.5. Chitosan is one of the most abundant natural polymers, which is nontoxic,biodegradable, and can be chelated with heavy metal ion by the active interface which ismade by chitosan’s functional groups such as hydroxyl, amine groups.the flaxen highpolymer Chitosan-6-OTs-β-CD/Sym-Diph-enyl-Thiourea is prepared by the method thatChitosan is crosslinked to the inclusion complex of6-OTs-β-CD/Sym-Diphenyl-Thiou-rea,This high poly-mer has synergy,and it can make a contribution to improve theproperty of adsorbing mental ions.In this article, the adsorbing behaviors of Chitosan tothorium were explored initially.When pH=4，shaking for40min,the sorbent mass was up to29.37mg/g.