The Synthesis Of β-cyclodextrin Nanosponge And Its Application To The Adsorption Of P-nitrophenol

β-cyclodextrin nanosponge（NSCD）is a kind of cyclodextrin polymer which is synthesized by usingβ-cyclodextrin as monomer and chemically modified with a cross-linking agent.It has a highly cross-linked three-dimensional network structure with larger cavity size and more active sites.Therefore,as a new type of compound,it has various applications in the field of drug inclusion,drug transportation,functional materials and etc.In this paper,using conventional heating method withβ-cyclodextrin（β-CD）as the monomer and diphenyl carbonate（DPC）as the cross linker,the effects of reaction temperature,reaction time,material molar ratio[n（β-CD）:n（DPC）],solid-liquid ratio(β-CD（g）:DMF（m L）and the amount of catalyst on the yield ofβ-cyclodextrin nano sponge were investigated;On this basis,the microwave irradiation method was used instead of the traditional heating method,the reaction time,reaction temperature and material molar ratio were independent variables,and the product yield was the response value.The Box-Behnken design of response surface methodology was used to optimize the synthesis process and predict the product yield of NSCD;The crude products under the two methods were characterized by means of FTIR,DSC,PXRD,SEM,¹³C-NMR and BET after were purified by cable-type extraction;A series of NSCDs products were synthesized by microwave method and applied to the removal of organic pollutants p-nitrophenol（PNP）in water.the effects of different adsorbent dosage,initial concentration,p H value of adsorption solution and adsorption time on the removal rate of PNP were investigated.The experimental results show that:（1）The best reaction conditions of traditional heating method that reaction temperature was at 80℃,reaction time was 5h,material molar ratio was 1:7,solid-liquid ratio was 2:10,catalyst dosage was 1:2,the product yield was 50.35%under this condition;（2）The optimum reaction conditions were obtained as follows:the reaction time was 87 min;the reaction temperature was90℃;the molar ratio was 1:1.75.Under the optimum reaction conditions,the product yield of 70.71%was obtained;（3）the characteristic peaks of carbonyl appeared at1760 cm^-1in the FT-IR spectrum and new characteristic peak appears at 155 ppm in13C-NMR spectrumcompared with that of freshβ-CD,which indicate the successful crosslinking ofβ-CD and DPC;The results of DSC showed the thermal degradation temperature of the NSCD was about 260℃PXRD results shows that the as-synthesized NSCD obtained from our microwave-assisted method had higher crystallinity than those prepared with conventional heating method,consistent with our SEM results.The BET analysis showed an increase in the specific surface area of product as the molar ratio increase,while the pore size changed in the opposite tendency.The reaction time of the optimized process was nearly four times shorter than the traditional method and the yield was increased by 20%～30%;（4）Adsorption experiments showed thatβ-cyclodextrin nanosponges could remove about 80%of the organic pollutants PNP in water.The kinetic model study showed that the adsorption behaviour for PNP conform to the pseudo-second-order dynamics equation better.which also layed a certain foundation for the application of NSCD as adsorption materials theoretical and experimental basis.