Enhanced air filtration performance and intelligent monitoring by MOF-functionalized ultrafine poly(lactic acid) fibers

The extensive use of traditional non-biodegradable filtration materials in industrial and medical sites has caused tremendous ecological and environmental pressure. For this reason, the research and development of poly(lactic acid) (PLA) fibrous membranes have become a cutting-edge hotspot. Based on this, the surface engineering strategy of using coaxial electrostatic spinning to embed high dielectric performance metal-organic framework (MOF) materials into fibers is proposed to prepare PLA nanofibrous membranes with excellent electronegativity, high electroactivity, and complete degradability for respiratory protection equipment, which can simultaneously achieve high-efficiency filtration and respiratory status monitoring. By regulating the fiber morphology and improving the electroactivity, the physical interception and electrostatic adsorption ability of the fibers were improved to enhance the filtration efficiency of particulate matter. The results of multiple characterization tests showed that the average fiber diameter was reduced by 33% (304 nm), the surface potential was increased by 38% (1.8 kV), the dielectric constant was increased by 55% (1.7), and the output voltage was increased by 74% (87 V). The filtration efficiency for PM_0.3 is up to 99.65% (32 L/min), and even at a high flow rate of 85 L/min, the filtration efficiency is still at 99.30% with no significant attenuation. Integrating the sensing function based on respiratory protection can realize the real-time monitoring of human respiratory status, which provides a reference for the early diagnosis of diseases and has a broad application prospect in the field of personal protection.