The invention discloses a preparation method of a layer-by-layer
casting ultrathin asymmetric bipolar membrane, and belongs to the technical field of membrane separation. The invention aims to solve the problems that the
total thickness of the traditional bipolar membrane is small, the water
decomposition rate is low, and the conversion efficiency of different salts is obviously different. The asymmetric bipolar membrane is prepared by using a layer-by-layer
casting method, and the thickness of the anion exchange layer and the cation exchange layer of the membrane is regulated, so that
ion leakage is avoided, and the product purity is remarkably improved; the anion-cation exchange layer is prepared from a
polymer with charge, and the adhesion capacity of the membrane is greatly improved by virtue of
electrostatic attraction through the characteristic of opposite charge of the anion-cation exchange layer, so that the membrane is prevented from swelling in water. According to the invention, the anion and cation exchange membranes are adhered together through
electrostatic adsorption force by virtue of the characteristic of opposite charges, the
adhesion strength of the membrane is enhanced by virtue of the
chemical compatibility of SPPSU and QPPO, the membrane has good
mechanical property, and the
service time and frequency of the membrane are improved.