| Literature DB >> 32473458 |
Oisik Das1, Rasoul Esmaeely Neisiany2, Antonio Jose Capezza3, Mikael S Hedenqvist4, Michael Försth5, Qiang Xu6, Lin Jiang6, Dongxiao Ji7, Seeram Ramakrishna7.
Abstract
The onset of coronavirus pandemic has sparked a shortage of facemasks in almost all nations. Without this personal protective equipment, healthcare providers, essential workers, and the general public are exposed to the risk of infection. In light of the aforementioned, it is critical to balance the supply and demand for masks. COVID-19 will also ensure that masks are always considered as an essential commodity in future pandemic preparedness. Moreover, billions of facemasks are produced from petrochemicals derived raw materials, which are non-degradable upon disposal after their single use, thus causing environmental pollution and damage. The sustainable way forward is to utilise raw materials that are side-stream products of local industries to develop facemasks having equal or better efficiency than the conventional ones. In this regard, wheat gluten biopolymer, which is a by-product or co-product of cereal industries, can be electrospun into nanofibre membranes and subsequently carbonised at over 700 °C to form a network structure, which can simultaneously act as the filter media and reinforcement for gluten-based masks. In parallel, the same gluten material can be processed into cohesive thin films using plasticiser and hot press. Additionally, lanosol, a naturally-occurring substance, imparts fire (V-0 rating in vertical burn test), and microbe resistance in gluten plastics. Thus, thin films of flexible gluten with very low amounts of lanosol (<10 wt%) can be bonded together with the carbonised mat and shaped by thermoforming to create the facemasks. The carbon mat acting as the filter can be attached to the masks through adapters that can also be made from injection moulded gluten. The creation of these masks could simultaneously be effective in reducing the transmittance of infectious diseases and pave the way for environmentally benign sustainable products.Entities:
Keywords: Bio-based membranes; Coronavirus; Electrospinning; Facemasks; Gluten
Mesh:
Substances:
Year: 2020 PMID: 32473458 PMCID: PMC7243761 DOI: 10.1016/j.scitotenv.2020.139611
Source DB: PubMed Journal: Sci Total Environ ISSN: 0048-9697 Impact factor: 7.963
Fig. 1(a) Schematic illustration of the electrospinning process to produce gluten nanofibre mats. (b) SEM micrograph of gluten nanofibers, modified from (Johansson et al., 2010). (c) SEM images of PVA/gluten nanofiber, reproduced with permission from (Dhandayuthapani et al., 2014). Copyright 2014 American Chemical Society.
Fig. 2Schematic illustration of the carbonisation process that can produce carbon nanofibre mats (cooling jacket aids in rapid temperature reduction after the completion of reaction).
Improvement of the fire retarding properties of gluten with lanosol addition (Note the significant reduction in PHRR value). Table modified from (Das et al., 2020b).
| Samples | Cone calorimeter results | ||||||
|---|---|---|---|---|---|---|---|
| TTI (s) | PHRR (kW/m2) | TPHRR (s) | THR (MJ/m2) | FPI | CO | CO2 | |
| Gluten | 28.5 ± 0.7 | 703.4 ± 48.7 | 207.5 ± 60.1 | 103.7 ± 2.3 | 0.041 | 0.031 ± 0.002 | 1.28 ± 0.04 |
| Gluten + 4 wt% Lanosol | 31.0 ± 2.8 | 353.3 ± 3.4 | 115.0 ± 70.7 | 89.6 ± 7.4 | 0.088 | 0.048 ± 0.010 | 1.13 ± 0.04 |
TTI = Time to ignition; PHRR = Peak heat release rate (lower is better); TPHRR = Time to PHRR; THR = Total heat release; FPI = Fire performance index (higher is better).
Fig. 3(a) The enhancement of mechanical property of gluten with addition of carbon, (b) reduction in water sorption in gluten as a result of carbon addition. Figure modified from (Das et al., 2019a).
Fig. 4Schematic showing the final shape and internal structure of the potential facemasks.
Regulations/test used to certify facemasks.
| Regulation / Test | Scope | Limitation | Note |
|---|---|---|---|
| Swedish Standard SS-EN 149 + A1:2009 | Respiratory protective devices – Filtering half masks to protect against particles | At least 92% of the tested elements cannot leak >5% particles | Value taken for FFP3 device class. |
| NIOSH 42 CFR 84 US (NIOSH 1995) | Filtering capacity | At least 95% of the influent particles should be filtered | NaCl particles are used as surrogate particles. Typical values for N95 respirator masks. |
| T4D bacteriophage virus filtration, by | Test the filtration property of different filter layers | 1 h filtration time resulted on “infinite” T4D virus capture, while 2 h gave 1.1 × 108 | Based on a FFP2 mask |
| Relative survivability (RS) of MS2 viruses on filters, by | Test the ratio of virus survival on treated filters relative to untreated filters | 1. PF PP filter (DuPont™ 01361 N): RS = 1 ± 0.1. | |
| ASTM F2100 – 19e1 | Standard specification for performance of materials used in medical facemasks | Medical facemask materials are required to: | Values based on a Level 1 barrier. |
Fig. 5Lanosol added gluten creating inhibition zone towards E.coli (Image modified from (Das et al., 2019a).