Preparation Of Novel ?-Cyclodextrin Polymer And Its Adsorption Properties To Organic Dyes

?-Cyclodextrin is a seven-membered polysaccharide with a cavity structure that can form polymers with organic compounds that have a benzene unit structure.Due to its own structural the polymer has been applied to wastewater treatment.Organic dyes are one of the most difficult contaminants in wastewater.However,the research on the cyclodextrin-based polymers has been carried out to show that the adsorption effect of such polymers on organic dyes in wastewater?such as methylene blue,Congo red,methyl orange,etc.?is not satisfactory.researchers have been researching and exploring novel and efficient adsorbents in order to efficiently to removal wastewater organic dyes.In this paper,a new type of ?-cyclodextrin polymer based on tetrafluoroterephthalonitrile as crosslinking agent was developed and the adsorption of organic dyes in wastewater was studied.In order to further improve the adsorption properties of ?-cyclodextrin polymers,several new ?-cyclodextrin polymer derivatives adsorbents were synthesized and their adsorption properties to organic dyes in wastewater were studied.The main contents are as follows:?1?was synthesized by ?-cyclodextrin??-CD?crosslink with tetrafluoroterepHthalonitrile?TFPN?.The structure of CDP was confirmed by FTIR,solid-state 13 CNMR and TG,and SEM was used to characterize the surface morpHology of CDP.The adsorption behavior of CDP on methylene blue and Congo red were studied systematically.In the process of adsorption of methylene blue,it was found that the adsorption equilibrium was achieved for 1 hour,but the equilibrium time of Congo red was 3 h.When the temperature is in the range of 20-50 oC,the adsorption amount of the two adsorbates increases with the increase of temperature.With the increase of pH,the adsorption capacity toward methylene blue increases and the adsorption capacity toward Congo red first increases and then decreases.The thermodynamics study showed that the adsorption process of CDP on methylene blue was monomolecular adsorption,and the maximum adsorption capacity was 361.1mg/g when the tempture is 303 K.?2?Derivatives of three ?-cyclodextrin polymers were prepared.The carboxylated ?-cyclodextrin polymer?CDP-COOH?is prepared by reacting?-cyclodextrin with sodium hydroxide?NaOH?;?CDP-CONH₂?is prepared by the reaction of ?-cyclodextrin polymer with acetaldoxime?CH₃CHNOH?catalyzed by copper oxide?CuO?;The amidoxime ?-cyclodextrin polymer is prepared by reacting?-cyclodextrin polymer with hydroxylamine?NH₂.OH?;FTIR and solid 13 CNMR were used to determine the structural formula.The adsorption of methylene blue by CDP-COOH was studied systematically.The results showed that CDP-COOH showed selective adsorption in the study of adsorption of methylene blue and methyl orange.By studying the amount of adsorbent,time,pH value of the adsorption factors.The results showed that the amount of adsorbent was 10 mg,CDP-COOH removed methylene blue in short time?6min?,the optimum pH value were 9,and the maximum adsorption capacity was 664 mg/gs.?3?The ?-cyclodextrin polymer was reacted with ethanolamine?NH₂CH₂CH₂OH?to prepare ethanolaminated ?-cyclodextrin?EA-CDP?,and the structure was determined by FTIR and 13 CNMR and TG and SEM.Adsorption performance research show that adsorption properties of EA-CDP toward methylene blue is not ideal,but the adsorption toward Congo red and methyl orange was good.Adsorption on mixed methylene blue and methyl orange showed that EA-CDP exhibited selective adsorption.The pH experiment found that EA-CDP achieved the best adsorption effect at pH = 2.5.