A low-cost and reusable photothermal membrane for solar-light induced anti-bacterial regulation

Abstract

In this work, a simple, low-cost, and applicable strategy for preparing membranes which allow photothermal conversion and have excellent anti-bacterial ability is proposed. Two steps, including soaking pristine glass fiber membranes in (NH₄)₂S₂O₈ solution and exposing the membranes to pyrrole vapor, afford an in situ surface polymerization of pyrrole monomers and darkening of the filtration membrane. A few characterization methods, together with a home-made air-cleaning testing system, are used to evaluate the photothermal conversion performance and anti-bacterial ability of the membranes. The surface temperature of the polypyrrole-modified membranes successfully reaches 129.4 °C and E. coli bacteria are reduced by 99.999% under illumination of 4.5 sun solar light. Compared with traditional one-off disinfectant methods, this anti-bacterial membrane is cost-effective, reusable, and could achieve non-contact sterilization without leading to significant environmental threats. Such a straightforward manufacture also offers great promise for industry-level production of a photothermal membrane, opening a new avenue to fabricate environment-friendly anti-bacterial materials and systems.