Pressure-Assisted In-Depth Hydrophilic Tailoring of Porous Membranes Achieving High Water Permeability, Excellent Fouling Resistance and Superior Antimicrobial Ability

Abstract Biofouling occurs at any wet structure including external surface and internal pore walls. Although the external surface biofouling can be limited by conventional methods, mitigating biofouling on the internal pore walls is still challenging. To address this issue, a novel pressure-assisted strategy was designed to tailor porous membrane surface for forming an in-depth multifunctional coating layer. The built ultrathin coating (ca. 26.3 nm) with hydrated and antimicrobial functions emerged on both external surface and inner pore walls of membranes via π-π interaction, hydrogen bonding and entanglements under unique pressure assistance. Such in-depth surface tuned porous membrane can achieve high separation performance (water flux ∼ 519.7 L m-2 h-1, BSA rejection ∼95.1%), excellent fouling-resistance (FRR∼94.2%) and superior antimicrobial effects (>99%) simultaneously. Our pressure-assisted in-depth modification strategy can open a new door to constructing omni-directional anti-fouling membrane towards highly efficient water treatments, and inspire abundant porous material modifications for diverse applications such as marine anticorrosion, adsorption separation and drug controlled release.