Electrospun membrane of PLA/calendula with improved UV protection and stable filtration performance

The "dual carbon" strategy and the severe air pollution problem have spurred the development of environmentally friendly functional filters. However, the performance stability of degradable polymers under ultraviolet (UV) irradiation needs to be explored and addressed. Loading natural small molecules onto electrospun fibers can enhance their functionality and sustainability. This study explores the use of calendula extract to protect polylactic acid electrospun fibers from UV degradation and provide antibacterial properties. A double-layer filter was created using straightforward sequential electrospinning. Only one-third of the fiber membrane's thickness contains drugs, resulting in an 88 % inhibition rate against Staphylococcus aureus. Its UV protection capability has been significantly enhanced. The calendula filters exhibited a tensile strength loss rate of only 23 %, compared to 30 % for the unmodified filters. Furthermore, the calendula extract altered the morphology and porous structure of the fibers, leading to an enhancement in the stable filtration efficiency of the membrane. It maintains a filtration efficiency of over 99 % at a flow rate of 32–85 L/min. This study has enhanced the stable filtration capacity of biomass filters and showcased their potential for UV protection and antibacterial applications.