Ultraviolet‐C as a viable reprocessing method for disposable masks and filtering facepiece respirators

In normal conditions, discarding single-use personal protective equipment after use is the rule for its users due to the possibility of being infected, particularly for masks and filtering facepiece respirators. When the demand for these protective tools is not satisfied by the companies supplying them, a scenario of shortages occurs, and new strategies must arise. One possible approach regards the disinfection of these pieces of equipment, but there are multiple methods. Analyzing these methods, Ultraviolet-C (UV-C) becomes an exciting option, given its germicidal capability. This paper aims to describe the state-of-the-art for UV-C sterilization in masks and filtering facepiece respirators. To achieve this goal, we adopted a systematic literature review in multiple databases added to a snowball method to make our sample as robust as possible and encompass a more significant number of studies. We found that UV-C’s germicidal capability is just as good as other sterilization methods. Combining this characteristic with other advantages makes UV-C sterilization desirable compared to other methods, despite its possible disadvantages.The authors would also like to acknowledge the project PLASMAMED—PTDC/CTM‐ TEX/28295/2017 financed by Fundação para Ciência e a Tecnologia (FCT), Fundo Europeu de Desenvolvimento Regional (FEDER) and Programa Operacional Competitividade e Internacionalização (POCI) in the frame of the Portugal 2020 program

The evaluation of the antibacterial capacity of tea tree functionalized microcapsules in textiles

The textile industry develops products that go beyond aesthetic concerns. Manufacturers functionalize these new textile products to provide them with new technical properties, to meet and even exceed user needs. The technical properties are diverse, from ultraviolet protection to antimicrobial or self-cleaning properties. The growth of microorganisms on textiles can result in unpleasant odors, stains or even accelerate the wear and tear of textile products. Microcapsules may contain natural or synthetic components in their core, capable of providing the desired properties to textiles (Figure 1). In addition, a shell protects the core and its design allows a gradual release of the main component. In this work, microcapsules were dyed to prevent the appearance of stains. This research tested the antibacterial capacity of microcapsules functionalized with tea tree essential oil on polyester fabric (PES). The fabric was tested with dyed and undyed microcapsules to ensure no dye interference. This research evaluates antibacterial capacity using the following standard bacteria: Staphylococcus aureus and Escherichia coli

Evaluation of fabrics' resistance for surgical aprons after washing-sterilization process / Avaliação da resistência de tecidos para aventais cirúrgicos após processo de lavagem e esterilização

A surgical center is a unique place for biochemical risks, specially concerning surgical aprons, as they tend to be soaked with fluids from both patients and its users during procedures. This study evaluates how the common fabrics used as raw material in reusable surgical aprons behave after washing-sterilization process. In order to perform such analysis, this study uses three types of fabrics: 100% cotton, mixed (67% cotton and 33% polyester), and 100% polyester. The variables “grammage,” “pore area,” and “bacterial growth” were evaluated in three different moments. The variables “grammage” and “pore area”, presented less wear out in cotton fabric. However, it is noticed that textiles with natural fibers (e.g., cotton or mixed) had a higher incidence of bacterial growth. Even though cotton fabric presented one of the highest incidences of bacterial infestation, it was chosen as the best raw material for surgical aprons. To solve this problem mentioned above, we suggested using antibacterial finishes, which are common while manufacturing reusable surgical aprons

Functionalization of woven fabrics for antimicrobial capability using microcapsules with essential oils

[Excerpt] The functionalization of textiles covers multiple objectives, such as the allocation of perfumes, antimicrobials, some drugs, phase change materials. Among these goals, the antimicrobial capability ensures that microorganisms do not thrive on textiles (Fig. 1), allowing users to use these products safer in different scenarios. This research evaluates the antimicrobial capacity of cotton fabrics through the application of microcapsules containing essential oils.The authors are grateful to the Agência Nacional de Inovação for the funding of the Project 4NoPressure - POCI-01-0247- FEDER-039869 and ARCHKNIT POCI-01-0247-FEDER-03973, co-funded by the European Regional Development Fund (ERDF), through the Operational Programme for Competitiveness and Internationalisation (COMPETE 2020), under the PORTUGAL 2020 Partnership Agreement

Development of a plasma activated multifunctional polyester fabric using zinc oxide nanoparticles and citronella oil microcapsules

There is a high demand for the development of textiles possessing multifunctional properties for outdoor, protective and health care applications. The coating of polyester (PES) textiles with metal nanoparticles and essential oils may act in a synergistic mode to obtain materials with improved antimicrobial and UV-protection properties. However, the lack of functional groups onto PES structure makes the adhesion of particles a difficult task. In this work, PES fabric was activated by dielectric barrier discharge (DBD) plasma treatment, and functionalized with zinc oxide nanoparticles (ZnO NPs) and poly (methyl methacrylate) (PMMA)-citronella microcapsules by dip-coating

Sustainable and multifunctional natural fiber-based electric wire sheaths for smart textiles

Envisioning the development of sustainable products for improvement of daily life quality, a cable-like composite using natural fibers was developed to be potentially used in smart textiles. Natural fibers such as jute and hemp were used along with Bekinox®VN yarn. Bekinox®VN is a stainless steel conductive yarn often used in intelligent textiles within a wide range of applications such as antistatic, power and signal transfer, thermal conductivity or even as a heat resistant sewing yarn. Furthermore, applying a chitosan coating on the surface of the sheath will confer antibacterial properties, thus preventing the colonization and proliferation of bacteria, as well as natural fiber degradation. The chitosan coating was applied by a pad dry method. Tests were performed to evaluate the mechanical, electrical and antimicrobial properties. The results displayed that the best tensile strength was obtained for hemp fabric followed by cable composite. The antimicrobial properties were improved with the coating of chitosan and demonstrating excellent results against Gram-positive and Gram-negative bacteria. Although chitosan reduces the mechanical strength of the sheath, it confers antibacterial activity, which not only will preserve the fiber in the structure but will also protect human skin against possible cross-contaminations.This work was funded by ERDF through the COP and FCT projects: UID/CTM/00264/2021, PLASMAMED PTDC/CTM TEX/28295/2017, ARCHKNIT POCI-01-0247-FEDER-039733, FATORST+ POCI-01-0247-ERDF-047124, MEDCOR PTDC/CTM-TEX/1213/2020, 4NoPressure POCI-01-0247-FEDER-039869 financed by FEDER through POCI under the “Portugal 2020” programme. RDVF and AIR also acknowledge Ph.D. scholarships SFRH/BD/145269/2019 and SFRH/BD/137668/2018, respectively

Sustainable and multifunctional natural fiber-based electric wire sheaths for smart textiles

Envisioning the development of sustainable products for improvement of daily life quality, a cable-like composite using natural fibers was developed to be potentially used in smart textiles. Natural fibers such as jute and hemp were used along with Bekinox®VN yarn. Bekinox®VN is a stainless steel conductive yarn often used in intelligent textiles within a wide range of applications such as antistatic, power and signal transfer, thermal conductivity or even as a heat resistant sewing yarn. Furthermore, applying a chitosan coating on the surface of the sheath will confer antibacterial properties, thus preventing the colonization and proliferation of bacteria, as well as natural fiber degradation. The chitosan coating was applied by a pad dry method. Tests were performed to evaluate the mechanical, electrical and antimicrobial properties. The results displayed that the best tensile strength was obtained for hemp fabric followed by cable composite. The antimicrobial properties were improved with the coating of chitosan and demonstrating excellent results against Gram-positive and Gram-negative bacteria. Although chitosan reduces the mechanical strength of the sheath, it confers antibacterial activity, which not only will preserve the fiber in the structure but will also protect human skin against possible cross-contaminations.This work was funded by ERDF through the COP and FCT projects: UID/CTM/00264/2021, PLASMAMED PTDC/CTM TEX/28295/2017, ARCHKNIT POCI-01-0247-FEDER-039733, FATORST+ POCI-01-0247-ERDF-047124, MEDCOR PTDC/CTM-TEX/1213/2020, 4NoPressure POCI-01-0247-FEDER-039869 financed by FEDER through POCI under the “Portugal 2020” programme. RDVF and AIR also acknowledge Ph.D. scholarships SFRH/BD/145269/2019 and SFRH/BD/137668/2018, respectively

Enhancing the antimicrobial efficacy of polyester fabric impregnated with silver nanoparticles using DBD plasma treatment

The functionalization of polyester fabric (PES) with antimicrobial agents presents huge number of potential applications in advanced products. However, the lack of functional groups and the high PES hydrophobicity make the functionalization processes costly, prolonged and requires the use of polluting chemical compounds. In this work, dielectric barrier discharge (DBD) plasma treatment, an affordable and environmental-friendly method, was used to introduce new chemical groups, increase the surface energy and roughness of PES in order to improve the adhesion of silver nanoparticles (AgNPs) in its surface. The PES functionalization was evaluated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and antimicrobial efficacy against Staphylococcus aureus and Escherichia coli. Despite some additional oxidation, the DBD plasma- treated PES showed superior adhesion of AgNPs and excellent antimicrobial efficacy even after 10 washing cycles (WC)

Imidazolium salt and dielectric barrier discharge plasma treatment to enhance the conductivity of fabrics impregnated with pedot:PSS

Conductive textiles are a class of materials with a growing interest due to their potential applications in medical, healthcare, comfort, protective clothing, and sportswear sectors. They can be used for the development of smart textiles able to answer to different external stimuli such as thermal, mechanical, chemical, electrical, magnetic, and optical. The complex poly (3,4-ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) is the most explored polymer to prepare conductive textiles. Dopants can be introduced to add or remove electrons from the backbone of PEDOT:PSS, resulting in increased conductivity. Salts such as 1-butyl-3-methylimidazolium octyl sulphate (IZ) may promote ionic interactions with PEDOT:PSS, stimulating a microstructure reorganization. Moreover, the dielectric barrier discharge (DBD) plasma treatment has been shown to improve the adhesion of coatings by modifying the surface roughness, surface chemistry, and hydrophilicity of the fabrics. In this work, untreated and DBD plasma-treated polyester (PES) fabrics were impregnated with PEDOT:PSS with and without the addition of imidazolium salt (0.2M) as a dopant. Using the IZ, it was possible to adapt the textile materials into resistors, where the applied current converted electrical energy into heat. The developed textiles can be used to produce heating garments