Abstract: With the rapid development of industrialization and urbanization, particulate matter (PM) pollution has seriously endangered human health. The WHO indicates that around seven million people die globally each year due to the air pollution. To minimize the health risks and plastic pollution, the use of electrostatically spun polylactic acid (PLA) nanofibrous air filters is of great significance.
Nevertheless, fiber filtration materials tend to feature dense stacks, which inevitably lead to a sudden increase in air resistance, reducing wearer comfort and raising the energy consumption of the device. Moreover, due to the poor in-situ electret effect of PLA fibers, the charges deposited on the fiber surface or in its vicinity are prone to escape, tremendously restricting their application in long-term stable filtration. To confront the aforementioned issues, the highly dielectric imidazolate framework-8 (ZIF-8) with nano-sized (~200 nm) were synthesized through microwave-assisted method. Then the coaxial electrospinning technique was applied to introduce it into the shell layer PLA solution to regulate the fiber morphology and enhance the surface electroactivity, which ultimately improved the filtration performance of PLA nanofibrous membranes (NFMs).
Benefitting from the in-situ high-pressure polarization enhancement of the electrostatic effect during the spinning process, as well as the charge storage capacity of ZIF-8 itself, the electroactivity of the fibrous membrane has been notably increased, enabling long-lasting electrostatic filtration. Synchronously, the constructed nano-protruded fibers could effectively reduce turbulent phenomena in the airflow, thereby decreasing air resistance. Additionally, the triboelectric nanogenerator (TENG) composed of the prepared NFM also demonstrated potential applications in physiological monitoring, highlighting promising prospects for practical use.
 

electroactivity,PM0.3 filtration,polylactic acid nanofibers,respiratory monitoring,ultra-low pressure drop