Preparation of novel superhydrophilic anti-fouling PVDF modified membrane via ring-opening and polymer crosslinking for highly efficient oil-water separation with enhanced permeate flux stability under extreme pH environments

• A novel superhydrophilic membrane via the surface modification method was proposed. • The membrane achieved enhanced permeate flux with high oil-water separation efficiency. • The prepared membrane can treat a wide range of oil-water emulsions. • The membrane exhibits excellent anti-fouling and anti-oil adhesion properties. • The membrane showed flux stability under extreme pH conditions (pHs of 1,3,10,12). This work developed a novel superhydrophilic and anti-fouling PVDF/Sac-100/PAA/NaHCO 3 membrane for efficient oil-water separation by modification of the PVDF membrane surface through the reaction of polymer crosslinking and ring-opening reagents via dip coating. The reaction led to the formation of a stable hydration layer coating on the PVDF membrane surface, resulting in a superhydrophilic surface. The prepared membrane achieved an optimum stable pure water flux of 5491.61 L . m −2. h -1 and an oil water permeate flux of 438.63 L . m −2. h -1 , approximately fourfold higher than the original membrane, with an oil rejection of 98.82%. More efficient separation is made possible by the enhanced water affinity of the surface of the modified membrane. This novel membrane demonstrated excellent oil rejection and improved flux for three different types of oil-water emulsions, with improved antifouling properties after four cycles of filtration, maintaining a flux recovery ratio of 90.40%. The membrane showed excellent stability, maintaining its superhydrophilic properties at different extreme pH conditions of 1, 3, 10, and 12 with oil rejection efficiencies over 98.64%. The membrane had highly stable pure water and permeate flux at all pH with the highest at pH of 3. This membrane can treat various oil-water emulsions and holds great potential for industrial oily wastewater separation.