β-环糊精/聚多巴胺功能化纤维膜的制备及其对水中有机污染物的吸附

To solve the problem of environmental pollution caused by various organic pollutants in water system, it is of great significance to develop multi-functional water purification materials. In this study, carboxylated β-cyclodextrin（cm-β-CD）with unique cavity structure and complexation was used as the main adsorption site, and polydopamine coating（s-PDA）with adhesion and rich catechol groups and amino functional groups was used as the intermediate layer. The functionalized fibrous membrane（PU/PVDF/s-PDA/cm-β-CD）was obtained by chemical bonding on the surface of polyurethane（PU）/polyvinylidene fluoride（PVDF）electrospun fibers. The functionalized fibrous membrane was characterized by scanning electron microscopy, water contact angle test, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and other methods. The results showed that the successful incorporation of s-PDA and cm - β - CD components on the fiber surface could endow the multiple adsorption sites for the adsorption material. Thus, the adsorption of various charged organic pollutants in water could be realized efficiently. At the same time, the functionalized fibrous membrane could reach the tensile strength of 14.90 MPa, and the elongation at break of 100.50%, which had excellent flexibility and was easy to separate from the water during the adsorption process. Methylene blue（MB） and phenolphthalein（PHP） were chosen as organic pollutant models with different charge properties for adsorption experiments. PU / PVDF / s-PDA / cm - β - CD functionalized fibrous membrane showed good adsorption capacity for both cationic organic pollutant MB and anionic organic pollutant PHP. The fitting results of adsorption kinetics models indicated that the adsorption behavior of MB and PHP conformed to the Pseudo-second-order kinetic model, and the main adsorption mechanism involved π - π conjugation and electrostatic interaction, as well as host and guest complexation and hydrogen bonding, respectively. The membrane prepared in this study provides a new idea for the removal of various charged organic pollutants in water, and has potential applications in separation, purification and molecular filtration.