| ?-Cyclodextrin??-CD?is a non-toxic cyclic oligosaccharide with a very unique tubular hollow structure.They possess a hydrophilic outer surface and a hydrophobic cavity,which can form host–guest inclusion complexes with various guest molecules.However,the low solubility of?-CD hinders its practical application.Therefore,We need to modify it to widen its application in different fields.Nowadays,more and more scholars synthesize different kinds of cyclodextrin and make them widely used in the fields of environment and medicine.Therefore,the study on the solubilization performance of?-cyclodextrin-immobilized mesoporous silica for adsorption of methyl violet and hydroxypropyl-?-cyclodextrin on diphenylthiourea from aqueous solution was studied.The main tasks are as follows:1.The structure and properties of?-CD were introduced,the application of?-CD and its derivatives and the synthesis method of inclusion complexes were investigated,and the methods for determining the inclusion ratio were analyzed.2.Using 1,1'-carbonyldiimidazole and tetraethyl orthosilicate as raw materials,?-cyclodextrin??-CD?was used to support mesoporous silica.3.??-CD@SiO2?as dye wastewater treatment.?-CD@SiO2 were characterized by infrared spectroscopy,then Scanning electron microscope was used to study the external morphology of?-CD@SiO2.The thermal stability was confirmed by thermogravimetric analysis.The formation of substances were proved by X-ray diffraction and the specific surface area of?-CD@SiO2 was analyzed by nitrogen adsorption-desorption isotherm.The results show that the mesoporous?-CD@SiO2 was successfully synthesized,and the specific surface area and pore volume of?-CD@SiO2 will be affected as the crosslinking agent increases.4.?-CD@SiO2 is used as an adsorption material to study the adsorption of methyl violet in dye wastewater solution.The effects of initial concentration,contact time,and adsorbent dose on the adsorption behavior of methyl violet were studied by static batch adsorption.The results showed that the maximum adsorption capacity is approximately36.25mg/g when the initial concentration was 34 mg/L,the contact time was 13 h,and the adsorbent dose was 5 mg.4.The experiments were designed by esponse surface method to design experiments and establish mathematical models.The parameters such as initial concentration,contact time,and adsorbent dose were used as independent variables to investigate the effect on the adsorption of methyl violet dye.second-order polynomial regression models were derived and analysis of variance was utilized to judge the accuracy of the selected model.The optimal adsorption conditions for methyl violet were obtained by BBD method:the initial concentration was 34 mg/L,the contact time was 13 h,and the adsorbent dose was 5 mg.The model predictions are in good agreement with the experimental values.Adsorption kinetics data showed that the adsorption process of methyl violet dye matched the pseudo-second-order kinetic model to a high degree,indicating that the chemical adsorption was not physical adsorption.The obtained isotherm adsorption data shows that the Langmuir isotherm model is more suitable for experimental data than the Freundlich isotherm model,indicating that?-CD@SiO2 adsorption of methyl violet is mainly a single-layer adsorption rather than a multilayer adsorption.5.Cyclodextrin inclusion complex?HP-?-CD@DPTU?was prepared by co-precipitation method using hydroxypropyl-?-cyclodextrin and diphenylthiourea as raw materials.The newly synthesized inclusion complex were characterized by Infrared spectroscopy,thermogravimetric analysis and X-ray powder diffraction.It can be known from the phase solubility method that hydroxypropyl-?-cyclodextrin and diphenylthiourea form an inclusion compound with an inclusion ratio of 1:1.It can be seen from the solubilization experiment that after the formation of clathrate with diphenylthiourea and HP-?-CD,the water solubility of diphenylthiourea is enhanced. |
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