UC Riverside

Piezoelectric polymer, which can generate electricity under mechanical strain, have many different applications in medical field, energy generation and harvesting and most recently, as an air filter for face mask. With the global pandemic, the demand for personal protective equipment (PPE) such as face masks is higher than ever. N95 masks are considered the gold standard PPE against the viral pathogens and have thus suffered a shortage many times throughout the pandemic. In addition, the electrostatic charge inserted into the melt-blown polypropylene fiber-based mask material to capture bacterial and viral particles is easily removed during the disinfection process, allowing for only single use. Thus, creative solutions to enhance the reusability while exhibiting comparable protection efficiency to the N95 masks are highly desirable.Though polyvinylidene fluoride tetrafluoroethylene (PVDF-TrFE) has so far exhibited the highest piezoelectric charge constants, its high cost deems it unsuitable for industry-scale production. The cost effective PVDF with lower piezoelectric properties was thus chosen as the host polymer. Electrospinning not only is a simple, cost-effective, scalable method to fabricate polymer nanofibers, but also allows for fine tuning of process conditions, enabling precise control of nanofiber properties such as morphology, which has recently been shown to significantly affect piezoelectric properties. The overarching goal of this project is to fabricate multifunctional composite nanofibers with air filtration and antimicrobial capabilities enabled by piezoelectric effect. Diameter of PVDF nanofibers with various antimicrobial additives (e.g., silver) function was optimized via process control of electrospinning. Additionally, antimicrobial, percent removal, filter efficiency and pressure drop testing were conducted to compare electrospun PVDF nanofibers with current N95 mask. During the preliminary results, Silver Nanoparticles embedded PVDF nanofiber exhibited great potential to be used as a multifunctional, longer lasting, and easier to breathe face mask filter.