Polyethylenimine Grafted Chitosan Nanofiber Membrane as Adsorbent for Selective Elimination of Anionic Dyes

In order to improve the adsorption capacity of chitosan to organic dyes, the amino rich functionalized chitosan electrospun nanofibers membrane was prepared. In the process of high efficiency synthesis, PGMA and PEI were grafted on the surface of CS NFMs in turn. By means of XRD, ATR-FTIR and XPS, the successful introduction of amino group into CS was confirmed. The selective adsorption capacity of CS-PGMA-PEI NFMs for anionic dyes was studied. The adsorption kinetics analysis shows that the adsorption process of CS-PGMA-PEI NFMs is mainly pseudo second-order model. Its adsorption isotherms can be described by the Langmuir model and it conforms to monolayer adsorption. The maximum adsorption capacity of Congo red calculated by Langmuir model is 657.47 mg/g. CS-PGMA-PEI NFMs has selective adsorption capacity for Congo red/methylene blue mixture. CS-PGMA-PEI NFMs also showed good circulation stability. This study provides a method for the synthesis of water purification membrane.