Ion exchange composite film with selectivity on single cation

Abstract

The invention provides an ion exchange composite film with selectivity on a single cation as well as a preparation method and an application thereof. The composite film comprises a cation ion exchange base film and a polyethyleneimine modified layer, wherein the depositing amount of polyethyleneimine on the cation ion exchange base film is 2.0-200.0 g / m<2>; and the thickness of the ion exchange composite film is 50-500 microns. The single cation is Cu<2+>, Zn<2+>, Ni<2+>, Hg<2+>, Ag<2+>, Pt<2+>, Co<2+> and Cr<3+> and the ion exchange composite film can replace the common ion exchange composite films to be mounted in an electrodialyzer. The ion exchange composite film disclosed by the invention has the advantages of simple operation of a preparation method, green and non-toxic preparation process and adaptation to large-scale industrial production.

Description

technical field

[0001] The invention relates to the technical field of membrane separation, in particular to a preparation method and application of an ion-exchange composite membrane selective to a single cation. Background technique

[0002] Membrane separation technology is regarded as a typical "green chemistry" because of its advantages of convenient continuous operation, easy scale-up, low energy consumption, and high energy utilization rate. The process has involved or hoped to apply membrane separation technology. The single cation selective separation membrane with excellent performance has broad application prospects in the resourceful extraction of rare metal ions in seawater, and the resourceful recovery and treatment of wastewater containing heavy metal or precious metal ions. Currently commercially available membranes that can achieve ion-selective separation mainly include ion-exchange membranes and nanofiltration membranes. The ion exchange membrane realize...

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