3D printed photo-sensitized microfiltration membranes for simultaneous water filtration and pathogen management

Abstract

3D printing is emerging as a transformative approach in functional materials fabrication, enabling precise control over structural parameters, offering opportunities to custom-design permeability, selectivity, and fouling resistance of membrane materials. The ability to fabricate membranes with near-isoporous pore size distribution further enhances their potential for advanced separation applications. The development of formulation and engineering solutions to support the formation of nanoporous nanocomposites with extremely accurate control over the nano-additives distribution is demonstrated in this study with the incorporation of Zinc phthalocyanine (ZnPc), a visible-light-responsive photosensitizer, to offer reactive oxygen species (ROS)-mediated photodynamic inactivation. This study introduces the development of 3D-printed microfiltration membranes, integrating engineered pore structures with photodynamically active surfaces to enhance filtration and antimicrobial performance. Morphological characterization revealed a structural evolution from globular to sheet-like and rod-like formations, significantly influencing pore size, wettability, and surface charge. Photodynamic assessments validated efficient ROS generation, enhancing methylene blue degradation and E. coli inactivation under irradiation. Filtration trials confirmed ZnPc-enhanced bacterial rejection and biofouling resistance, with the 2 wt% ZnPc membrane achieving 99.5% E. coli rejection under irradiation. Furthermore, virus filtration experiments confirmed the efficacy of 1 wt% ZnPc membrane, achieving a 2.56-log, or 99.72%, reduction in Influenza A virus (IAV) recovery. These findings demonstrate that 3D-printed ZnPc-functionalized membranes offer a dual-function approach, combining precise structural control with photodynamic antimicrobial activity, making them promising candidates for next-generation, light-assisted water treatment systems.