Preparation method of layer-by-layer self-assembled antibacterial hydrogel filtering membrane

The invention discloses a preparation method of a layer-by-layer self-assembled antibacterial hydrogel filtering membrane. Dissolving sodium alginate with a copper ammonia solution to obtain a mixed aqueous solution A, and preparing an acidic cationic polyelectrolyte aqueous solution B at the same time; soaking a base membrane in an aqueous solution B to coat the surface of the membrane with a layer of cationic polyelectrolyte, then soaking the base membrane in a mixed aqueous solution A, enabling sodium alginate and the polyelectrolyte in the aqueous solution B to be self-assembled into a complex, enabling a copper ammonia solution to release copper ions when encountering acid, and cross-linking the sodium alginate to obtain a copper ion cross-linked macromolecular complex hydrogel membrane; soaking the membrane into the aqueous solution B, then soaking the membrane into the aqueous solution A again, and repeating the steps for many times to obtain the layer-by-layer self-assembled antibacterial hydrogel fil