Electrospun nanofibers for medical face mask with protection capabilities against viruses: State of the art and perspective for industrial scale-up

Polyvinylidene Fluoride-co-hexafluoropropyle Electrospun Nanofiber Membranes for PM0.3 Filtration

“…Therefore, air filtration materials play a fundamental role in protecting individuals by effectively filtering out harmful airborne particles. Currently, fiber air filtration materials are extensively used primarily due to their high permeability and large specific surface area. − The main filtration mechanisms of air filtration materials include diffusion, inertia, interception, gravity, electrostatic adsorption, and other filtration mechanisms. − The most widely used fiber air filtration material is the melt-blown and spunbond nonwoven, which is enhanced with higher electrostatic forces under the application of the electret process to improve its air filtration efficiency via the electrostatic adsorption mechanism. , However, rapid attenuation of electrostatic forces and limited stability of filtration efficiency are inevitable. − These drawbacks not only limit further improvements in filtration efficiency but also induce higher air resistance.…”

Upscaling of Electrospinning Technology and the Application of Functionalized PVDF-HFP@TiO2 Electrospun Nanofibers for the Rapid Photocatalytic Deactivation of Bacteria on Advanced Face Masks

“…In this perspective, commonly used face masks, such as surgical and filtering half-masks (i.e., Filtering Face Pieces (FFPs)), turned out to be essential barriers to protect the wearer from submicron particles and biological contaminants that can be present in the form of droplets or aerosols in the atmosphere, reducing the spreading of and infection by the coronavirus (SARS-CoV-2) [1][2][3]7]. In order to determine the effectiveness of these face devices in preventing users from being infected by large and small droplets, which can be potential bacteria or virus carriers, the European Norm (EN) specifies several performance filtration criteria, which include Bacterial Filtration Efficiency (BFE) and Particle Filtration Efficiency (PFE) [8][9][10]. However, Viral Filtration Efficiency (VFE) is an unrecognized standard parameter that is commonly employed to quantify the degree of protection of face devices from virus aerosols [11][12][13].…”

“…The layers forming a commercial filter media are mainly produced by means of the Melt-Blowing (MB) method and are generally composed of polypropylene (PP), i.e., a thermoplastic polymer, whose fiber diameters are about the submicron size [20]. Unlike MB, Electrospinning (ES) proved to be a promising technique to customize a broad range of synthetic and natural polymer-based electrospun membranes with fiber diameters and pore sizes down to the nanoscale, providing remarkable performance in both Particulate Matter (PM) capture and low pressure drop [8]. Furthermore, the implementation of active metal oxide Nanoparticles (NPs), such as ZnO [21], TiO 2 [22], and metal Ag [23], as well as other bioactive hybrid nanocomposites, including aggregation-induced emission (AIE)-active photosensitizer [24], metal-organic frameworks (MFO) [25], and rose bengal (RB) [26] in polymer-based electrospun nanofiber filters, have proven to be advantageous to design environmentally friendly face masks with tailored filtration performance as well as photocatalytic properties, which make them able to deactivate both bacteria and viruses after an exposure to light sources, and thus extending the lifetime quality of the device and making it reusable [8].…”

“…Unlike MB, Electrospinning (ES) proved to be a promising technique to customize a broad range of synthetic and natural polymer-based electrospun membranes with fiber diameters and pore sizes down to the nanoscale, providing remarkable performance in both Particulate Matter (PM) capture and low pressure drop [8]. Furthermore, the implementation of active metal oxide Nanoparticles (NPs), such as ZnO [21], TiO 2 [22], and metal Ag [23], as well as other bioactive hybrid nanocomposites, including aggregation-induced emission (AIE)-active photosensitizer [24], metal-organic frameworks (MFO) [25], and rose bengal (RB) [26] in polymer-based electrospun nanofiber filters, have proven to be advantageous to design environmentally friendly face masks with tailored filtration performance as well as photocatalytic properties, which make them able to deactivate both bacteria and viruses after an exposure to light sources, and thus extending the lifetime quality of the device and making it reusable [8]. The generation of Reactive Oxygen Species (ROS) induced at the nanofiber surface level by the irradiation of these embedded photocatalytic nanomaterials with visible-UV light involves a complete inactivation of bacteria and viruses by drastically affecting protein and enzyme function, due to the electrostatic interaction with the bacterial cell walls and membranes [27][28][29].…”

Tunable and Biodegradable Poly(Ester Amide)s for Disposable Facemasks

“…Electrospinning [5,6] is a highly promising technique that was shown to improve facemask performance and reduce the amount of polymer used compared to conventional mask fabrication processes. [7][8][9] However, even though this fabrication method is more environmentally friendly, the solution is not ideal as it still produces plastic waste. Instead, one of the most promising solutions is to fabricate the facemasks using biodegradable polymers.…”