Preparation And Adsorption Properties Of The Ph-sensitive Hydrogel

Cyclodextrins (CDs) are form a doughnut-shaped structure with a hydrophobic cavity and hydrophilic exterior, its hydrophobic cavity can be embedded in a variety of organic compounds to form inclusion complexes, and the physical and chemical properties of inclusion compounds can be changed. CDs also can be modified through copolymerization with some functional groups or polymerization as monomers Because of this property, Cyclodextrin is widely used in environmental protection. Its unique molecular structure can be used to treat industrial wastewater. In recent years, the research of modified cyclodextrin polymer used in environmental is a hot issue. In this paper, two CDs polymer hydrogels were synthesized as the follow methods: modified cyclodextrin with maleic anhydride at first, then copolymerized with acrylic acid or acrylamide. The two hydrogels can be used as a new type of absorption material, for the adsorption of dye molecules and phenol from water pollution. The new hydrogels can be recycled when treated after adsorption.In this paper, we have done the following works:1 A brief overview was given for the basic conditions of CDs and hydrogels, also the research advancement of CDs and hydrogel through the known synthesis and application.2 A novel pH-sensitivity hydrogel named P(MAH-P-CD-AA) was synthesized by the treatment of modifiedβ-CD compounds and acrylic acid, then the hydrogel was characterized by Infrared spectrometry and Thermal gravity analysis. Ammonium persulfate was initiator. Study on the swelling behavior and adsorption property for basic dyes in the aqueous solutions of the hydrogel, and also the pH influences on swelling behavior and adsorption property.3 Polyacrylamide itself can be used for water purification. A novel pH-sensitivity hydrogel P(MAH-β-CD-AM) was synthesized by the treatment of modifiedβ-CD compounds and acrylamide, then the hydrogel was characterized by Infrared spectrometry. Ammonium persulfate was initiator. Study on the swelling behavior and adsorption property for acid dyes in the aqueous solutions of the hydrogel, and also the pH influences on swelling behavior and adsorption property.4 Base on the study of swelling behavior and adsorption properties for dyes in wastewater, the adsorption properties for phenolic were further studied.5 Presently, relatively reports about the recycle of adsorption materials after use in existing water treatment methods was few. We hope that hydrogels can be reused after treatment to avoid secondary damage to the environment. In the Paper, the effects of some dye elution methods were compared and investigated to found that photodegradation was a more effective approach.The results show that the two pH-sensitivity hydrogels can be used for the sorption of dyes and phenolic pollutants in wastewater. The hydrogel can be separated from the water and reused after treatment.