Preparation of antibacterial composite fiber membrane for air filtration with micro/nano structure

With the aggravation of environmental pollution and the worldwide epidemic of infectious diseases, there is a higher demand for air filtration materials to intercept fine particulate matter and capture biological pollutants. Polypropylene (PP)/polycarbonate (PC) blends were melt blown and electrospun with polytetrafluoroethylene (PTFE) on their surfaces. The PP/PC/PTFE membranes structure with micro-nanostructure was constructed through the melt-blown layer with micron structure and the electrospun layer with the nanostructure. Carboxymethyl chitosan (CMCS) was loaded onto the surface of the PP/PC melt-blown layer. The synergistic effect of micro-nanostructure and CMCS can effectively capture PM2.5 and make the composite membrane have excellent antibacterial performance. The inhibition rates of PP/PC/PTFE composite membrane loaded with 5% CMCS against Staphylococcus aureus and Escherichia coli reached 81.54% and 86.1%, respectively. The filtration efficiency of PP/PC/PTFE composite membrane loaded with 5% CMCS is close to 100% for 0.25 μm particles, and the average filtration efficiency for 0.200–4.596 μm and 0.200–2.500 μm particles is 97.31% and 97.27%, respectively. After washing and drying five times, the corresponding inhibition rate only lost 16.52% and 4.24%. The micro/nano structure composite membrane prepared in this study has good antibacterial performance, high filtration efficiency, good stability, and is an excellent antibacterial high efficiency air filter. It provides a new idea for the preparation of air filter fiber composites.