BETA-CYCLODEXTRIN has relatively good solubility in water, and it is not easy to recycle when used in water phase, which greatly limits its application in water treatment. Cyclodextrin is a natural organic substance, safe, non-toxic and biodegradable. It is a better choice for cyclodextrin as adsorption, flocculation and photocatalytic materials. In order to improve solubility, dispersibility and long-term Stability, proper modification of β-cyclodextrin to make it have multifunctional, water-soluble or water-insoluble, high-dispersibility and other functional materials is very meaningful in water treatment. Usually, the methods of modifying cyclodextrin include chemical method and enzymatic method. Enzymatic method is mainly used to prepare branched cyclodextrin. Chemical method can use the outer alcoholic hydroxyl group of β-cyclodextrin to change its physical (solubility, mechanical strength, Size, specific surface area, etc.), chemical (chemical adsorption, complexation, electrical neutralization) and biological (antibacterial, degradable, etc.) properties, thus expanding its application in the field of water treatment. Chemically modified β-cyclodextrin can be classified into the following two categories:
1) Use the hydroxyl energy on the outer surface of BETA-CYCLODEXTRIN to react with multifunctional substances to generate various cyclodextrin derivatives with cyclodextrin as the skeleton to improve or reduce the concentration of β-cyclodextrin in water Solubility, it is mainly used as flocculant or coagulant in water treatment. It can play the role of moisture-proof, anti-oxidation and color protection in the food field. In the field of medicine, it can play the role of improving the solubilization of insoluble drugs. Analytical chemistry Domain can participate in the formation of stationary phase, play a role in molecular recognition and improve separation effect. β-cyclodextrin derivatives can be divided into cyclodextrin ethers, cyclodextrin esters, cyclodextrin-polymers and cross-linked cyclodextrins according to the chemical reaction of the introduction of new groups; The properties can be roughly divided into three types: hydrophilic, hydrophobic and ionic. Hydrophilic cyclodextrin derivatives include branched cyclodextrin, low molecular weight cyclodextrin polymer (molecular weight 3k ~ 6k), methyl cyclodextrin, hydroxyethyl cyclodextrin and hydroxypropyl cyclodextrin, etc. Hydrophobic cyclodextrin derivatives include ethyl cyclodextrin, acetyl cyclodextrin and polyacrylamide cyclodextrin, etc.; ionic cyclodextrin derivatives include quaternary ammonium or polyamine cyclodextrin, N- (2,3-Epoxypropyl)trimethylammonium chloride cyclodextrin, carboxymethyl cyclodextrin, alkylsulfonic acid cyclodextrin, phosphate ester cyclodextrin and sulfate ester cyclodextrin, etc.
2) Building BETA-CYCLODEXTRIN on other carriers can synthesize water treatment adsorbent materials with long service life, good mechanical properties or high dispersion properties. Carriers mainly include inorganic molecules, organic synthetic polymers and natural product polymers. Among them, inorganic carriers include graphene oxide, carbon nanotubes, SiO2 nanoparticles, magnetic Fe3O4 nanoparticles and zeolite, etc.; organic synthetic polymer carriers include polyethyleneimine, polyvinyl alcohol, polypropylene, polypropylene, polystyrene and Polymers such as polyester nanofibers; natural polymer carriers include cellulose and its derivatives, wood flour, chitosan, gelatin, sodium alginate, etc.