The ongoing coronavirus taking over the world has put many countries in a terrible predicament of lockdowns which can barely continue in many societies. People are required to commence a new form of corona-adapted social lie; however, it needs time to assimilate into the daily routine. According to the World Health Organization (WHO) and the data from epidemiology studies, COVID-19, which can persist in aerosol form, is primarily transmitted among people through respiratory droplets within a few feet away.
In line with all researchers in every corner of the world, nanotechnologists are employing their both relevant experience and cutting-edge achievements to find a panacea for ceasing this pandemic in general and to diminish its airborne risks in particular. Diverse face masks such as N95, N99, surgical masks, and technical respirators, being now available or close-to-market, leverage nano-related technologies to enable or enhance their performance against COVID-19, some of which – namely – nanofibers, nanocomposites, nanoparticles, and graphene technologies are the most paramount ones.
To begin with, nanofiber membranes technology, the most plausible and universal approach, is based on the dense spiderweb-like 3D network of extremely thin nanofibers (e.g., polyacrylonitrile and nano-coco-carbon™), provides high surface area for super-high trapping properties. These membranes are incorporated into respiratory masks, providing high breathability and filtration efficiency thanks to their strong and durable structures.
Nanocomposite membranes technology is a proper substitute for nanofibers to improve the performance of face masks in battle against COVID-19. This technology uses an active filtration system including nanoparticles-incorporated nanofibers (e.g., polypropylene impregnated with 5% copper oxide nanoparticles), ensuring maximum capture and containment within the structure. The functionalization of nanofibers, before being incorporated into the masks, is another approach at hand to enhance virus filtration potential through the simultaneous addition of nanoparticles to the hot nanofibers during the synthesis process.
As an effective solution for killing coronaviruses captured in the masks filters, nanoparticles technology provides the field with tremendous supports. Nanoparticles such as copper oxide and diamond can make self-cleaning sanitizing masks through either incorporation into fibrous membranes or deposition as an ultra-thin layer on the respirator. Nanoparticles can also use as hydrophobic coatings to protect the respirators against transmission of the virus by making them impervious to water. Self-regenerating germicidal TiO2-based face masks show efficient germ-killing power under zero light conditions and with self-regeneration capability by light.
The face mask can provide effective protection as the first-hand defense against air-transmitted germs, bacteria, and viruses. The TiO2 layer can be refreshed by direct sunlight (UV) exposure to kill off accumulated germs. Moreover, nanosilver-improved masks can help protect users so that the nanoparticles continuously release ions, which are able to kill viruses and bacteria.
Last but not least, graphene technology contributes to fighting against coronavirus through the bacteriostatic properties of graphene-introduced membranes. However, the most eye-catching application of this technology in the field is likely killing the trapped microorganisms in the mask's filter with the aid of laser-induced graphenes through conducting electrical charge, which is a close-to-market respirator developed by some companies. A low-level electrical charge passes through the membrane when it is plugged into a portable battery pack via a USB port, which can repel any particles trapped in the mask.
A broad spectrum of companies and researchers has pitched in to benefit the merits of the aforementioned nanotechnologies in developing proficient face masks, some of which are summarized in the table below.
Companies involved in developing nanotechnology-based face masks
|
No. |
Organization |
Country |
Technology |
Nano insights |
Properties |
|
1 |
nanofibers membranes |
patented ReSpimask® technology based on an extreme density of nanofiber filters |
protection against inhalation of PM2.5 and PM1.0 smog and dust particles, virus removal, bacteria removal, anti-smog, anti-pollution, anti-fungi, anti-spore, anti-mildew |
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|
2 |
nanofibers membranes |
YAMASHIN Nano Filter™ containing a 3D structure of extremely thin synthetic polymer-based nanofibers |
disposable, virus removal, super-high virus trapping |
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|
3 |
nanofibers membranes |
natural, organic, and sustainable nanofibers using an exclusive nano-coco-carbon™ filter technology, containing the unique combination of naturally produced coconut shell carbon and nanofiber matrix |
breathable, eco-friendly, recyclable, 99.99% filtration efficiency |
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|
4 |
nanofibers membranes |
four layers of filter protection, including a water-repellent layer made of non-woven fabric, two layers of nanofibers providing high filtration efficiency, and a silky skin-friendly layer which cares for facial skins |
breathable, virus removal, bacteria removal, 98.75% filtration efficiency |
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|
5 |
nanofibers membranes |
on the basis of ReSpimask® technology |
virus removal, allergens-free, bacteria removal, chemicals-free |
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6 |
nanofibers membranes |
aligned nanofibers with a diameter of 100~500 nm in orthogonal or unidirectional directions |
washable for more than 20 times, water-resistant, 94% filtration efficiency |
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7 |
nanofibers membranes |
smart masks which can kill 99% of bacteria within 5 minutes |
breathable, virus removal, bacteria removal, bacteria-killing |
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8 |
nanofibers membranes |
fabric laminates with a nanofiber layer, forming a barrier against penetration of microorganisms on the principle of mechanical detection |
anti-bacterial activity, anti-microbial activity, moisture permeability, virus removal, anti-dust, breathable, disposable |
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|
9 |
nanofibers membranes |
highly breathable cellulose nanofiber-based material |
nanoparticle removal, virus removal, anti-pollution, breathable, disposable, biodegradable |
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|
10 |
nanofibers membranes |
multiple-layer mask comprised of a layer of 20g PP spunbond as a supportive inner layer (for more comfortability), a layer of 40g spunbond, a layer of nanofibers coated on spunbond in order to filter nanoparticles, a layer of 17g meltblown as a filter for microparticles, a layer of 40g spunbond, a layer of polyacrylonitrile nanofibers is coated as the middle layer of the mask and can absorb 80-100% of particles bigger than 300 microns |
virus removal, nanoparticle removal, breathable |
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|
11 |
nanofibers membranes |
multi-layer mask: one of the middle layers contains nanofibers with nanometric diameters to prevent harmful particles from entering the respiratory system |
high filtration efficiency |
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|
12 |
nanofibers membranes |
enhanced performance thanks to a large surface-to-volume ratio and high porosity, provide by nanofibrous network |
high filtration efficiency, large surface-to-volume ratio, high porosity |
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|
13 |
nanofibers membranes |
produced by three layers which the second layer is consist of polymeric nanofiber, being under 100 nm |
anti-bacterial activity, anti-microbial activity, virus removal, anti-pollution, breathable, impermeable |
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|
14 |
nanocomposite membranes |
made of a novel modular filtration system manufactured with the innovative nanocomposites of PLACTIVE® and MDflex®, including three layers of a non-woven polypropylene impregnated with 5% copper oxide nanoparticles |
anti-bacterial activity, virus removal, recyclable, antiviral, reusable |
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|
15 |
nanocomposite membranes |
a proprietary process technology to functionalize nanofibers, before being incorporated into the masks, which enhances virus filtration potential. This functionalization process allows you to feed in powders/particulates at the same time the fibers are being formed. This means that as the hot fibers are being formed, the powders/particulates naturally stick to the hot fibers ensuring maximum capture and containment within the structure. |
bacterial removal, virus removal, breathable |
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|
16 |
nanocomposite membranes |
developing a potential virucidal graphene-based composite ink in collaboration with Graphene Composites Ltd to fight COVID-19, containing silver nanoparticles functionalized graphene oxide nanocomposites that can be applied to fabrics including N95 face masks and other personal protective equipment (PPE) for significantly increased protection through both trapping and killing the virus. |
anti-fungal activity, antiviral, virucidal, virus-killing |
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|
17 |
(rebranded to Invisi Smart™) |
nanoparticles technology |
a self-cleaning sanitising surgical mask treated with an ultra-thin invisible layer (Protex) ranging between 1-2 micrometers in thickness, enough to protect from viruses |
anti-bacterial activity, self-cleaning, anti-microbial activity, anti-fungal activity, anti-viral, proven to kill 99.9% of all viruses and bacteria that come into contact |
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|
18 |
nanoparticles technology |
embedded nano-copper into polymer fibers, such as nylon, via a melt extrusion process, it was found that the antimicrobial effect lasted longer than other similar antimicrobial fabrics on the market. |
anti-microbial activity, anti-viral |
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|
19 |
nanoparticles technology |
ReSpimask® VK is made of a three-layer nanofiber membrane containing copper dioxide (CuO) nanoparticles into the nanofiber matrix |
virus filtration, virus-killing, 99.9% filtration efficiency, natural skin-like color |
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|
20 |
nanoparticles technology |
a hydrophobic nano-coating, developed in collaboration with the University of Houston, to improve the ability of surgical masks to protect against transmission of the virus by making them impervious to water |
anti-viral, hydrophobe
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|
21 |
nanoparticles technology |
an anti-pathogen fabric that could be used in masks using a patented nanotechnology process, containing zinc oxide nanoparticles |
anti-pathogen, virus removal, washable, anti-bacterial activity, anti-microbial activity |
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|
22 |
nanoparticles technology |
a protective coating on masks that would include a new nanoparticle to catch COVID19 and kill it within seconds through triggering a chemical reaction using ultraviolet light to destroy it |
virus removal, virus-killing |
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|
23 |
nanoparticles technology |
a nanodiamond coating to be employed in a new generation of the non-woven material of surgical masks |
virus-killing, anti-viral, breathable, waterproof, anti-bacterial activity |
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|
24 |
nanoparticles technology |
patented nanosilver technology |
anti-bacterial activity, environmentally-friendly, reusable |
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|
25 |
nanoparticles technology |
the world's first self-regenerating germicidal TiO2Ag face mask based on XTI's revolutionary Active-Nucleus Nano-Particle Technology |
anti-bacterial activity, moisture resistance, non-allergenic, anti-viral, germs removal, self-regenerating, 99.999% germ-killing power under zero light |
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|
26 |
graphene technology |
Made of the patented graphene material (i.e., G+® graphene) |
anti-bacterial activity, non-toxic, anti-microbial activity, bacteriostatic |
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|
27 |
graphene technology |
Guardian G-Volt masks based on laser-induced graphene that can conduct electrical charge to kill the trapped microorganisms in the mask's filter |
anti-bacterial activity, self-sterilizing, anti-viral, reusable, virus-killing |
