Face masks to fight against COVID-19 pandemics: A comprehensive review of materials, design, technology and product development

Abstract

The outbreak of COVID-19 has created renewed attention on research and large scale manufacturing of face masks. In the last two decades, usage of face masks for respiratory protection has gained increased importance as a measure to control the maladies and fatalities due to exposure to particulate pollutants and toxic pathogens. Numerous variants of surgical and high-performance respirator masks are available in the market, and yet the fibrous materials science researchers, manufacturers and public health agencies are making concerted efforts towards improvising them with respect to self-sterilisability, facial fit, thermo-physiological comfort, reusability and biodegradability, while maintaining or rather enhancing the filtration efficiency. This review article presents a compendium of materials, design and performance standards of existing face masks, as well as elaborates on developments made for their performance enhancement. The criticality of inculcation of good hygiene habits and earnest compliance to correct mask donning and doffing practices has also been highlighted. This review is expected to make valuable contributions in the present COVID-19 scenario when donning a face mask has become mandatory.

Scalable methods for directional assembly of fillers in polymer composites: Creating pathways for improving material properties

“…Melt spinning is a common technique in industry to manufacture thermoplastic polymers or polymer composite microfibers, [162][163][164][165] such as surgical and N-95 masks which have been heavily used during the COVID-19 pandemic. [166,167] To briefly introduce this process, polymer composites are first melt and pumped through a spinneret (die) containing single or multiple holes. The melt polymer fibers are then drawn, cooled, solidified, and collected on a take up wheel.…”

Nanoweb for Nanobugs: Nanofiber Filter Media for Face Masks

“…Beyond basic filtration, high performance nanofiber filters have since been further enhanced by integrating other functionalities through design and material development toward a new paradigm of smart protective devices. Face mask studies that emerged from the COVID-19 pandemic leveraged this size effect for nanofibers alongside the low basis weight, large surface area to volume ratio, and high porosity for use as multifunctional fabric systems within face masks. − Depending on the fiber material composition or surface modification, face masks can serve advanced functions such as antimicrobial, fluid-resistant, reusable, environmentally sustainable material use and disposal, pathogenic detection, and health data monitoring smart devices. − Hexadimethrine bromide (PB) and poly­(methyl vinyl ether- alt -maleic anhydride) (PMA) are cationic and anionic polymers, respectively, that have previously been electrospun with PVA for use as selective capture membranes in liquid filtration and microfluidic analytical systems. − This study extends the application of these polyionic nanofibers to air filtration, where the liquid–solid interface is localized to each aerosol droplet and fiber surface. PB and PMA when mixed with PVA can influence the strength of the positive or negative charges that are generated in the R-TENG assembly, serving as both FE enhancement and potential selective capture diagnostic nanofiber webs.…”