Fabrication of air filters with advanced filtration performance for removal of viral aerosols and control the spread of COVID-19.

COVID-19 is caused via the SARS-CoV-2 virus, a lipid-based enveloped virus with spike-like projections. At present, the global epidemic of COVID-19 continues and waves of SARS-CoV-2, the mutant Delta and Omicron variant which are associated with enhanced transmissibility and evasion to vaccine-induced immunity have increased hospitalization and mortality, the biggest challenge we face is whether we will be able to overcome this virus? On the other side, warm seasons and heat have increased the need for proper ventilation systems to trap contaminants containing the virus. Besides, heat and sweating accelerate the growth of microorganisms. For example, medical staff that is in the front line use masks for a long time, and their facial sweat causes microbes to grow on the mask. Nowadays, efficient air filters with anti-viral and antimicrobial properties have received a lot of attention, and are used to make ventilation systems or medical masks. A wide range of materials plays an important role in the production of efficient air filters. For example, metals, metal oxides, or antimicrobial metal species that have anti-viral and antimicrobial properties, including Ag, ZnO, TiO2, CuO, and Cu played a role in this regard. Carbon nanomaterials such as carbon nanotubes, graphene, or derivatives have also shown their role well. In addition, natural materials such as biopolymers such as alginate, and herbal extracts are employed to prepare effective air filters. In this review, we summarized the utilization of diverse materials in the preparation of efficient air filters to apply in the preparation of medical masks and ventilation systems. In the first part, the employing metal and metal oxides is examined, and the second part summarizes the application of carbon materials for the fabrication of air filters. After examination of the performance of natural materials, challenges and progress visions are discussed.

Additive Manufacturing of Natural Materials as a Multidisciplinary Approach in Engineering Education

This research shows results from additive manufacturing as an important strategy to produce multidisciplinary skills in engineering students. Case studies are presented with materials and mechanical engineering, and arts as well. Two animals and a natural fiber from Colombia were manufactured with the fused deposition modeling (FDM) technique present at the University of Antioquia Museum and in classroom as well, aiming involve the students in a new learning and technological experience. Results reveal the potential of this technology in education and particularly in the motivation for learning and deep comprehension of details of nature only visible at the micro-scale. Moreover, the virtual models for the printing process also open new possibilities after the Covid new challenges for virtual education. © 2022, The Minerals, Metals & Materials Society.

Production of antimicrobial, natural, and reusable material for stitching eco-friendly, extra-protective face masks

Purpose: The COVID-19 pandemic has popularized wearing face masks for personal protection. However, the protection afforded by a mask is decreased if an individual accidently touches the outer surface of the mask and then touches other parts of their face. To overcome this problem, antimicrobial masks have become commercially available. However, many are disposable and/or made from synthetic antimicrobial agents which have a negative impact on the environment. The purpose of this study was to create material for stitching antimicrobial masks that are reusable and natural. Design/methodology/approach: The authors developed natural antimicrobial finishes from Azadirachata indica, Butea monosperma and Litchi chinensis leaves. The authors used biodegradable polyurethane binder and pad-dry-cure method to apply them on 100% cotton fabric. The authors used Fourier-transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) to confirm the application and ASTM E2149 to assess the efficacy and wash-resistance of the finish. Findings: Fabric treated with leaves of A. indica, B. monosperma and L. chinensis showed 80%, 100 and 100% antimicrobial activity, respectively. All fabrics were washed 25 times in home laundry cycles and maintained 100% of their antimicrobial effect. Originality/value: These findings highlight that B. monosperma and L. chinensis finishes on cotton fabric can be a used as a material for stitching antimicrobial, natural and reusable masks that provide more protection than traditional masks but do not pose the environmental concerns of disposable masks or synthetic finishes. This study can be furthered by performing more laundry cycles to determine if the finishes remain 100% effective beyond 25 cycles. © 2022, Emerald Publishing Limited.

Profile of Pangaia: a fast growing apparel brand, materials innovator and environmental steward poised for success

Pangaia is an apparel brand and materials science company headquartered in London, UK, which is best known for its portfolio of loungewear made using innovative biomaterials. The company was founded as recently as 2019, and in its 2020 financial year it achieved revenues totalling US$75 mn. However, the company is also focused on research and development (R&D) in the field of natural and renewable materials which have negligible impact on the environment and provide comparable performance, if not superior performance, to that of petroleum-based materials. The company gained some notoriety following the widespread outbreak of COVID-19 in March 2020 when demand for loungewear soared. Also, the outbreak of COVID-19 put environmental issues under the spotlight and, in many cases, it inspired consumers to reflect on the environmental damage caused by the goods which they purchase. Indeed, throughout the duration of the pandemic, online searches for sustainable fashion have increased year-on-year. Major strides can be expected from the company in the coming years in the development of innovative biomaterials, particularly biodegradable “alternative leather” materials, environmentally friendly dyes, and sustainable alternatives to virgin cotton fibre and virgin animal fibre. Indeed, the company looks set to make a significant impression on the global apparel market and beyond on the basis of these developments alone. © Textiles Intelligence Limited 2022.