Characterization and Filtration Efficiency of Sustainable PLA Fibers Obtained via a Hybrid 3D-Printed/Electrospinning Technique

Abstract

The enormous world demand for personal protective equipment to face the current SARS-CoV-2 epidemic has revealed two main weaknesses. On one hand, centralized production led to an initial shortage of respirators; on the other hand, the world demand for single-use equipment has had a direct and inevitable effect on the environment. Polylactide (PLA) is a biodegradable, biocompatible, and renewable thermoplastic polyester, mainly derived from corn starch. Electrospinning is an established and reproducible method to obtain nano- and microfibrous materials with a simple apparatus, characterized by high air filtration efficiencies. In the present work, we designed and optimized an open-source electrospinning setup, easily realizable with a 3D printer and using components widely available, for the delocalized production of an efficient and sustainable particulate matter filter. Filters were realized on 3D-printed PLA support, on which PLA fibers were subsequently electrospun. NaCl aerosol filtration tests exhibited an efficiency greater than 95% for aerosol having an equivalent diameter greater than 0.3 μm and a fiber diameter comparable to the commercially available FFP2 melt-blown face mask. The particulate entrapped by the filters when operating in real environments (indoors, outdoors, and working scenario) was also investigated, as well as the amount of heavy metals potentially released into the environment after filtration activity.

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

“…The enhancement of the ecotoxicity of the MPs released in open sea, which is provoked by the continuous accumulation of plastic coming from disposable masks at the landfills, is rising up nowadays a global concern [ 202 , 203 ]. Therefore, the urgent need to implement more sustainable development has become a relevant issue to address in the increasing demand of face masks [ 156 ]. To reduce the environmental impact due to the massive use of disposable masks, some researchers explored the fabrication of high efficiency filter material by employing recycled polyethylene terephthalate (PET) [ 164 ] ( Fig.…”

“…Therefore, the feasibility in using recycled materials such as PET and EPS for the fabrication of face mask could be considered to implement a circular economy and a significantly lowering in the environmental impact in terms of resources consumption and environmental pollution for future policies [ 205 , 206 ]. Also, the utilization of renewable and biodegradable thermoplastic polymers, such as PLA and polyvinyl butyral (PVB), has shown to be a sustainable alternative to produce effective filters comparable to many commercial face mask [ 156 , 157 , 173 , 174 , 207 ]. Wang et al.…”

Eco-Friendly Hierarchical Nanoporous Microfiber Respirator Filters Fabricated Using Rotary Jet Spinning Technology (RJS)

“…However, the low hydrolysis resistance and barrier to water vapor of PBS limited its processability for practical end-use application. An eco-friendly biopolymer, such as polylactic acid (PLA), outweighs the advantages of several other biopolymers and could be a promising candidate for face mask application. − …”

Biobased thin-film composite membranes comprising priamine–genipin selective layer on nanofibrous biodegradable polylactic acid support for oil and solvent-resistant nanofiltration

“…, chloroform and DMF). 26–28 Dimethyl carbonate (DMC) is an environmentally friendly solvent that can improve the renewability of polysaccharides, sugar-derived platform molecules, lignin-based phenolic compounds, glycerol, and fatty acids; 4,29 therefore, DMC can dissolve PLA. 30,31…”

“…25 Studies have been conducted on the PLA solution preparation using traditional solvents (e.g., chloroform and DMF). [26][27][28] Dimethyl carbonate (DMC) is an environmentally friendly solvent that can improve the renewability of polysaccharides, sugar-derived platform molecules, lignin-based phenolic compounds, glycerol, and fatty acids; 4,29 therefore, DMC can dissolve PLA. 30,31 Due to the chemical nature of PLA, electrospun nanofibrous supports are hydrophobic with a water contact angle in the range of 128°-136°.…”