Hierarchically Porous, Superhydrophobic PLLA/Copper Composite Fibrous Membranes for Air Filtration

Epidemics such as pulmonary tuberculosis and pertussis can spread quickly through the air in enclosed or small spaces. Most of these diseases are caused by various bacteria. In hospitals, nursing homes, and biology laboratories, the requirement for air quality is often high. Particulate air filters can remove infectious bacteria from the air, making them a good choice for local ventilation systems to capture and remove bacteria or other pathogenic microbes. With high surface area, electrospun poly­(l-lactic acid) (PLLA) fibrous membranes have the ability to capture small particles like bacteria. Moreover, copper has significant antimicrobial properties. In this Letter, we present a hierarchically porous PLLA membrane created through electrospinning and acetone treatment. Additionally, we describe two methods for loading copper particles onto the hierarchically porous PLLA membrane, thereby providing capabilities for capturing and killing bacteria. The experiments demonstrated that the final PLLA/Cu composite fibrous membranes exhibit not only excellent air permeability but also remarkable antimicrobial performance while maintaining bendability and superhydrophobic ability. This study provides a simple process, low energy cost, and environmentally friendly method to produce the copper-coated PLLA membrane, which is especially suitable for potential applications in high-flux filtration equipment in hospitals, nursing homes, and biology laboratories.