Durable Antibacterial and Antifungal Hierarchical Silver-Embedded Poly(vinylidene fluoride-co-hexafluoropropylene) Fabricated Using Electrospinning

The aim of this study was to demonstrate the use of electrospinning to produce hierarchical fibrous structures for antibacterial and antifungal applications. Silver nanopartides (Ag NPs) are produced in situ within an electrospinning solution with the help of a solvent acting as a reducing agent. Ag NP-filled poly(vinylidene Fluoride-co-hexafuoropropylene ) (PVDF-HFP) fibers were produced by electrospinning this solution. The collected fibers were placed on top of a porous anodized aluminum oxide (AAO) template, and the setup was heated above the glass-transition temperature (T-g) of the polymer. Heating above T-g enabled the polymer to flow into the porous channels of the AAO template and led to the fabrication of hierarchical PVDF-HFP fibers filled with Ag NPs. The microstructure of the samples revealed that the nanostructures were formed uniformly on the surface of the fibers. The wettability of the samples was measured by determining the contact angle, and it was revealed that the wettability of hierarchical fibrous structures was higher than the wettability of PVDF-HFP-filled Ag NPs. Lastly, the antimicrobial activity results revealed that both PVDF-HFP fibers filled with Ag NPs and the hierarchical PVDF-HFP fibers filled with Ag NPs exhibited inhibition against methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Candida albicans. The antibacterial and antifungal performance for the samples was determined, and it was found that the hierarchical fibrous structures showed the highest antibacterial and antifungal performance against MRSA, P. aeruginosa, and C. albicans in comparison to the neat PVDF-HFP fibers and PVDF-HFP fibers filled with Ag NPs. We also demonstrated that these fibers can be strongly antibacterial and antifungal after a number of usages. This may be attributed to the slow and long-lasting release of silver ions from the electrospun fibers. Hierarchical PVDF-HFP filled with Ag NPs showed the lowest relative bacterial viability (less than 5%) against MRSA in all three cycles. The relative bacterial and fungal viability against P. aeruginosa and C. albicans was determined to be less than 15%. These findings demonstrate that the fabricated antibacterial and antifungal fibers show tremendous promise for applications such as air filtration, water treatment, protective clothing, and so forth.

Automated summary

This study demonstrates the production of hierarchical fibrous structures filled with silver nanoparticles using electrospinning for antibacterial and antifungal applications. The hierarchical PVDF-HFP fibers exhibited higher wettability and superior antibacterial and antifungal performance compared to PVDF-HFP fibers filled with Ag NPs. The slow release of silver ions from the fibers contributed to their strong and long-lasting antibacterial and antifungal properties, showing potential for various applications such as air filtration, water treatment, and protective clothing.