Hydrophilic PVDF (Polyvinylidene Fluoride) composite ultrafiltration membrane and preparation method thereof

The invention discloses a hydrophilic PVDF (Polyvinylidene Fluoride) composite ultrafiltration membrane and a preparation method thereof, relates to membranes and preparation methods thereof and particularly relates to PVDF composite ultrafiltration membranes and preparation methods thereof. The hydrophilic PVDF composite ultrafiltration membrane and the preparation method thereof are used for solving the problem that the service lives of the existing PVDF ultrafiltration membranes are shortened because contaminants of protein and the like are easily adsorbed to the surfaces of the existing PVDF ultrafiltration membranes caused by the fact that the existing PVDF ultrafiltration membranes are strong in hydrophobicity and weak in contamination resistance. The hydrophilic PVDF composite ultrafiltration membrane disclosed by the invention is prepared through blending PVDF, a dopa assistant and a reaction product of end-epoxy PEO (Polyoxyethylene). The preparation method comprises the steps of dissolving the dopa assistant into a solvent, adding end-epoxy PEO so as to obtain a mixed solution, then adding PVDF powder in the mixed solution so as to obtain a blended membrane casting solution, standing the blended membrane casting solution until no bubbles exist, uniformly coating the blended membrane casting solution on a glass plate by using a scraping cutter, and obtaining the hydrophilic PVDF composite ultrafiltration membrane by using an immersion precipitation phase conversion method. The preparation method can be used for preparing the hydrophilic PVDF composite ultrafiltration membrane.