P(VDF-TrFE)/BaTiO 3 Nanofibrous Membrane with Enhanced Piezoelectricity for High PM 0.3 Filtration and Reusable Face Masks.

In the background of air pollution and regular COVID-19 prevention, personal protective masks are necessary for our daily life. However, protective masks with high PM filtration usually have poor air permeability and are mostly disposable, leading to a heavy burden on the environment. In this work, a reusable membrane based on piezoelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] nanofibers embedded with BaTiO nanoparticles (BTO NPs) was developed. The P(VDF-TrFE)/BTO composite nanofibers not only have enhanced piezoelectricity and surface polarity but also have reduced diameters that could be beneficial for electrostatic adhesion, pole-polar interactions, and mechanical sieving to increase the PM capture capacity. Moreover, the BTO NPs also improved the charge storage capacity of the composite membrane, which could further enhance the PM filtration efficiency after corona treatment. The piezoelectric mask based on P(VDF-TrFE)/BTO composite nanofibers has high filtration efficiencies of 96% for PM and 98% for bacteria, while the pressure drop was only 182 Pa, which is lower than the commercial N95 standard of 343.2 Pa. Furthermore, the piezoelectric mask has a long and stable filtration performance after 5 cycles of 75% alcohol disinfection, demonstrating that the P(VDF-TrFE)/BTO composite membrane has a potential application in personal protective masks with comfortable and reusable properties.