Surface Segregation of Partially Fluorinated Comb-Shaped Amphiphilic Copolymer in Pvdf Membrane: Experimental and Molecular Dynamic Simulation Study

Herein, we report the one-pot synthesis and molecular dynamics (MD) simulations of a partially fluorinated comb-shaped amphiphilic copolymer (PTPO) comprising short poly(2,2,3,3-tetrafluoropropyl methacrylate) (PTFPMA) and long poly(oxyethylene methacrylate) (POEM) chains for poly(vinylidene fluoride) (PVDF) membranes. PTPO exhibited a well-defined microphase-separated structure and had dipole-dipole interactions with PVDF. The hydrophilic POEM domains aligned with the surface, whereas the hydrophobic PTFPMA domains anchored within the PVDF matrix. Compared with the neat PVDF, the PVDF/PTPO membrane flux increased by up to 2300%, and the flux recovery ratio reached 95.7%, with high bovine serum albumin rejection. Furthermore, the PVDF/PTPO membranes demonstrated superior mechanical properties (>4 MPa) compared with those of the other PVDF-based ultrafiltration membranes. Posttreatments such as ethanol immersion improved the surface hydrophilicity without the leaching of PTPO. MD simulations provided insights into the interaction between the PVDF/PTPO blends and water nonsolvent and the free volume of the PVDF/PTPO membranes with varying PTPO loadings. This study suggests that the microphase separation of the comb-shaped amphiphilic PTPO can effectively improve the antifouling performance as well as water permeability of the PVDF membrane.