Metal coordination polyimide aerogel composite diaphragm as well as preparation method and application thereof

The invention provides a metal coordination polyimide aerogel composite diaphragm and a preparation method and application thereof.The preparation method comprises the steps that an aldehyde reagent and an aromatic diamine monomer react to synthesize an intermediate with double carbon-nitrogen double bonds, the intermediate and an aromatic dianhydride monomer are subjected to a condensation polymerization reaction in an organic solvent, and a polyamide acid solution is obtained; adding a metal salt into the polyamide acid solution to carry out coordination reaction, adding a cross-linking agent to carry out chemical cross-linking, and finally adding a dehydrating agent and a catalyst to obtain the polyimide sol. The polyimide sol is coated on the surface of the diaphragm to obtain a wet gel composite diaphragm, and then the composite diaphragm coated with the metal coordination polyimide aerogel is obtained through aging, solvent exchange and normal-pressure drying. The average pore size of the obtained compo