Abstract: Coal mine dust,fine particulate matter (PM) in the air and the existence of pathogens,seriously harm the ecological environment and human health. Traditional polymer membrane filters have shown a great role in dust,filtering PM and pathogens. However,traditional polymer materials are not degradable,which can easily lead to plastic pollution and microplastic hazards. It is urgent to develop degradable fiber filtration materials with high filtration efficiency and high antibacterial efficiency. In this paper,titanium dioxide (TiO2) nanoparticles were directly embedded into polylactic acid (PLA) nanofibers (PLA @ TiO2) by a combination of electrospinning-electrospray technology. At the same time,the spinning environment humidity was regulated to form a beaded structure,which effectively improved the electrical activity,electret performance and filtration performance of the fibrous membrane and provided excellent UV shielding and antibacterial properties. When the airflow rate was 85 L/ min,the filtration efficiency of the pure PLA fibrous membrane for PM0. 3 was only 83. 9%,and the air resistance was 654. 9 Pa. The PLA@ TiO2 fibrous membranes filtration efficiency was improved,and the air resistance was significantly reduced. When the TiO2 concentration was 4%,the filtration efficiency was 97. 9%. The air resistance was reduced to 260. 2 Pa. In addition,the antibacterial efficiency of the PLA@ TiO2 membrane against E. coli and S. aureus reached 100%. TiO2 embedded in PLA fiber could also enable the fibrous membrane to absorb ultraviolet radiation,and the ultraviolet transmittance (TUVB) of the PLA@ TiO2 fibrous membranes was reduced to 20. 1% compared with pure PLA fibrous membrane,which could prevent and avoid skin injury and other diseases. The combination of nanofiber electret properties and beaded structure provides efficient filtration,low air resistance,and high bacteriostatic efficiency. It provides a useful reference for reducing and preventing the occurrence of pneumoconiosis.

Key words: mine dust,nanofibrous membranes,long-term low-resistance,UV shielding,antibacterial properties