Preparation method of graft modified polytetrafluoroethylene (PTFE) microporous membrane with lasting hydrophilism

The invention relates to a preparation method of a graft modified polytetrafluoroethylene (PTFE) microporous membrane with lasting hydrophilism. The method comprises the following steps of: firstly, preparing a dopamine water solution; regulating a pH value to be 7-10; putting the PTFE microporous membrane into ethanol and wetting to be transparent; soaking into the dopamine water solution at room temperature; preparing a modifying agent water solution by using a hydrophilic reagent as a modifying agent; regulating a pH value to be 7-10; soaking the PTFE microporous membrane subjected to treatment of the dopamine water solution into the modifying agent water solution; and taking out and drying to obtain the gas modified PTFE microporous membrane. By using the method, the hydrophilic performance of the modified PTFE microporous membrane is obviously improved, the process is simple, and the modification effect keeps lasting and stable.