Photo-responsive polypropylene/zinc oxide/polydopamine-TEMPO composite membranes with light-induced self-sterilization

Face masks play a pivotal role in preventing infection transmission. However, the capture of infection-sourced particles in face masks poses challenges related to reuse, necessitating proper disposal. We developed a self-sterilizable polypropylene-based membrane for face masks to address challenges associated with infection transmission prevention. The membrane, created using 3D printing, underwent functionalization with zinc oxide (ZnO) and polydopamine (PDA)-TEMPO to achieve broad-spectrum light absorption and facilitate self-sterilization through photocatalytic and photothermal effects upon light exposure. The hydrophobic surface (water contact angle: 133 ​± ​2°) minimized moisture accumulation, and the membrane exhibited robust mechanical properties, including shear strength (1.25 ​± ​0.5 ​kPa) and peel resistance strength (112.8 ​± ​11.2 ​kPa). The evaluation demonstrated stability in airflow (0–500 ​cm 3 /s) and excellent aerosol filtration efficiency (94.8 ​± ​0.6 %) for particles (PM 0.3, PM 2.5, PM 10), comparable to commercial masks. The membrane showed antibacterial efficacy over five uses in a simulated respiratory environment. Safety assessments confirmed biocompatibility through cytocompatibility and skin irritation assays. In conclusion, this membrane offers efficient filtration and photo-triggered sterilization, presenting a promising solution for next-generation face masks to address concerns related to reuse, disposal, and infection control.