A “micro-explosion” strategy for preparing membranes with high porosity, permeability, and dye/salt separation efficiency

•A high porosity separation membrane was prepared using in-situ foaming technology.•The preparation of separation membrane by in-situ foaming technology has not been reported.•The membrane exhibited high permeability and good separation performance for dye/salt mixtures.•The in-situ foaming technology is universal for different types of separation membranes.