Investigation of Multifunctionality of Electrospun Poly(vinyl alcohol) Nanofiber Membranes Incorporating Boric Acid and Nanoencapsulated Curcumin: Filtration Performance, Antibacterial Activity, and Environmental Impact

Nanofibrous structures have a wide range of applications, including air filtration for fine particles. This study fabricated bead-free nanofiber membranes from aqueous poly(vinyl alcohol) (PVA) and PVA/boric acid (BA) solutions containing varying concentrations of nanoencapsulated curcumin (CUR) using the electrospinning method to investigate filtration performance against aerosols and bioaerosols, antibacterial activity, mechanical properties, and biodegradability. The prepared membranes were morphologically examined using field emission scanning electron microscopy (FE-SEM). In addition, Fourier transform infrared spectroscopy (FTIR) was used to investigate the incorporation of CUR into the fibers. The higher CUR content resulted in thicker fibers and significantly improved the mechanical properties of the samples. The filtration performance of the bead-free samples was evaluated for different particle sizes (0.3-3 μm) at airflow rates of 28.3 and 32 L min^-1. The incorporation of CUR enhanced filtration performance against chemical particles and microorganisms, mechanical characteristics, as well as antibacterial activity in the nanofibers. Nanofibers containing CUR could provide superior filtration performance, achieving approximately 100% efficiency for 0.3 μm particles and a pressure drop of 167 Pa at 32 L min^-1. Also, lower CUR concentrations in the nanofiber membranes demonstrated high bacterial filtration efficiency (BFE) (above 96%) against Staphylococcus aureus (S. aureus). Nanofibers containing CUR showed more effective antibacterial activity against Escherichia coli (E. coli) compared to S. aureus. Furthermore, biodegradability, as a specific aspect of environmental impact, was investigated in PVA and PVA/BA nanofibers containing CUR. According to the results, the biodegradability rate of PVA nanofibers decreased as CUR and BA were added to the membrane structure. A greater CUR concentration could also increase the biodegradability rate of PVA/CUR and PVA/BA/CUR nanofibers. As a result, green electrospun nanofibers containing CUR and BA offer a promising solution for environmentally friendly air filters targeting chemical particles and microbial contaminants.