Sterilizable and Reusable UV-Resistant Graphene-Polyurethane Elastomer Composites

Antipathogenic Applications of Copper Nanoparticles in Air Filtration Systems

The COVID-19 pandemic has underscored the critical need for effective air filtration systems in healthcare environments to mitigate the spread of viral and bacterial pathogens. This study explores the utilization of copper nanoparticle-coated materials for air filtration, offering both antiviral and antimicrobial properties. Highly uniform spherical copper oxide nanoparticles (~10 nm) were synthesized via a spinning disc reactor and subsequently functionalized with carboxylated ligands to ensure colloidal stability in aqueous solutions. The functionalized copper oxide nanoparticles were applied as antipathogenic coatings on extruded polyethylene and melt-blown polypropylene fibers to assess their efficacy in air filtration applications. Notably, Type IIR medical facemasks incorporating the copper nanoparticle-coated polyethylene fibers demonstrated a >90% reduction in influenza virus and SARS-CoV-2 within 2 h of exposure. Similarly, heating, ventilation, and air conditioning (HVAC) filtration pre- (polyester) and post (polypropylene)-filtration media were functionalised with the copper nanoparticles and exhibited a 99% reduction in various viral and bacterial strains, including SARS-CoV-2, Pseudomonas aeruginosa, Acinetobacter baumannii, Salmonella enterica, and Escherichia coli. In both cases, this mitigates not only the immediate threat from these pathogens but also the risk of biofouling and secondary risk factors. The assessment of leaching properties confirmed that the copper nanoparticle coatings remained intact on the polymeric fiber surfaces without releasing nanoparticles into the solution or airflow. These findings highlight the potential of nanoparticle-coated materials in developing biocompatible and environmentally friendly air filtration systems for healthcare settings, crucial in combating current and future pandemic threats.

Research progress in preparation, properties, and applications of medical protective fiber materials

A variety of public health events seriously threaten human life and health, especially the outbreak of COVID-19 at the end of 2019 has caused a serious impact on human production and life. Wearing personal protective equipment (PPE) is one of the most effective ways to prevent infection and stop the spread of the virus. Medical protective fiber materials have become the first choice for PPE because of their excellent barrier properties and breathability. In this article, we systematically review the latest progress in preparation technologies, properties, and applications of medical protective fiber materials. We first summarize the technological characteristics of different fiber preparation methods and compare their advantages and disadvantages. Then the barrier properties, comfort, and mechanical properties of the medical protective fiber materials used in PPE are discussed. After that, the applications of medical protective fibers in PPE are introduced, and protective clothing and masks are discussed in detail. Finally, the current status, future development trend, and existing challenges of medical protective fiber materials are summarized.

Colorless, Transparent, and High-Performance Polyurethane with Intrinsic Ultraviolet Resistance and Its Anti-UV Mechanism

Polyurethane (PU) is a widely used polymer material that will age under prolonged exposure to ultraviolet (UV) light, shortening the service life. Several methods have been used to prepare the anti-UV PU, including adding nonreactive anti-UV additives, functional fillers, and biological antioxidant molecules. However, the nonreactive anti-UV additives may migrate during long-term use, the functional fillers may damage the mechanical properties and seriously reduce the light transmittance of the sample, and the biological antioxidant molecules will inevitably color the sample. To solve these problems, in this work, a benzotriazole UV absorber (Chiguard R-455) was introduced into the PU molecular chains by in situ polymerization to prepare the nonmigrating intrinsic anti-UV PU sample with high performance and colorless transparency. The anti-UV PU samples exhibit light transmittance of over 88% in the visible range and superior mechanical properties with tensile strength higher than 65 MPa and elongation at break higher than 900%. After 24 h UV irradiation (200 W, 365 nm), the tensile strength and elongation at break of pure PU sample are significantly reduced to only 8.9 and 15.8% of the original one, respectively. On the contrary, the addition of Chiguard R-455 will endow the PU sample with excellent anti-UV performance. After 24 h UV irradiation, the tensile strength (67.2 ± 1.6 MPa) and elongation at break (917.4 ± 30.0%) of PU-0.5% (the content of Chiguard R-455 is only 0.5 wt %) have changed little compared with the sample without irradiation (67.4 ± 3.5 MPa and 919.4 ± 26.5%). Additionally, the anti-UV mechanism of the PU sample is systematically studied. This work provides a feasible method for preparing colorless, transparent, high-performance, nonmigrating intrinsic UV-shielding PU samples, which can be used as a UV light-shielding material in various fields with visible and aesthetic requirements, such as protection fields and wearable products.