ABSTRACT
The present pandemic has highlighted the necessity of infection protection gear as a crucial protective approach, particularly given the fact that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) readily infects individuals in poorly ventilated environments. Embedding antimicrobial function onto protection gear would have major implications in minimizing pathogen contamination and lowering healthcare associated illness. In this study, non woven polypropylene fabric (NWPP) which is widely used in personal hygiene products and hospital protective gears has been subjected to surface fictionalization with corona treatment. Surface polarity of the treated fabric was studied by use of dyne liquid which showed generation of surface polarization. Subsequently, the resultant surface polarized NWPP were spray coated with zinc oxide (ZnO) antiviral agent. The antiviral agents were rendered to adhere to NWPP by use of polyurethane solution coating on the fabric. The effect of antiviral coatings on NWPP fabric with the use of polyurethane solution as an adhesive were investigated in terms of antiviral activity and anti-bacterial activity against MS2 bacteriophage and Staphylococcus aureus and Klebsiella pneumonia bacteria respectively. Coating of surface polarized NWPP with polyurethene binder reduced the leaching of antiviral coating. More importantly, the fabrics exhibited promising antiviral and anti bacterial activity with 99.90 % reduction in microorganisms after 24 hours of exposure. © 2022 IEEE.
ABSTRACT
Glycyrrhizic acid and its primary metabolite glycyrrhetinic acid, are the main active ingredients in the licorice roots (glycyrrhiza species), which are widely used in several countries of the world, especially in east asian countries (China, Japan). These ingredients and their derivatives play an important role in treating many diseases, especially infectious diseases such as COVID-19 and hepatic infections. This review aims to summarize the different ways of synthesising the amide derivatives of glycyrrhizic acid and the main ways to synthesize the glycyrrhitinic acid derivatives. Also, to determine the main biological and pharmacological activity for these compounds from the previous studies to provide essential data to researchers for future studies. Supplementary Information: The online version contains supplementary material available at 10.1134/S1068162022050132.
ABSTRACT
The demand for air filtration products has increased significantly with the aggravation of air pollution and the pandemic of coronavirus disease (COVID-19). It is urgently needed to develop an air filtration membrane that exhibits lasting filtration performance and antibacterial activity. Herein, we report a large-scale blow spinning technique to produce polyvinylidene fluoride (PVDF) nanofiber membranes for highly efficient air mechanical filtration and its antibacterial modification by adding the silver nanoparticles (AgNPs). The PVDF nanofiber membrane with an area density of only 1.0 g/m2 exhibits the highest filtration efficiency of 98.63% for the particle with a size of 0.3 μm. After eliminating static electricity, there is almost no reduction in the filtration efficiency of particulate matter with a size larger than 1 μm and only 4.69% decrease in the particulate matter with a size of 0.5 μm. Hence, the PVDF nanofiber membrane with nanostructures for air filtration works mainly by the means of mechanical filtration. To inhibit the survival or growth of the intercepted bacteria on the membrane, the PVDF/AgNPs nanofiber membrane was fabricated by adding AgNPs to PVDF nanofibers, which exhibits the strongest antibacterial activity of more than 99% and an excellent filtration efficiency similar to that without adding AgNPs. The nanofiber membrane with antibacterial activity is expected to extend the service or storage time or be reused without loss of filtration performance. Additionally, large-scale production of nanofiber filtration membranes has been realized using a multi-needle blow spinning machine. © 2022 American Chemical Society.
ABSTRACT
The demand for air filter media at indoor and outdoor is increasing tremendously due to air pollution and especially for problems related to airborne particulate matter (PM). To realize that, here a class nanofiber air filter media with strong antibacterial activity, hydrophobic nature, high filtration efficiency with low pressure drop is prepared. Novel organic-inorganic nanocomposite nanofibers used in this work benefited for the multifunctional performance. Amorphous titanium dioxide (mTiO2) is utilized for air filtration application which exhibits excellent enhancement of PM2.5 filtration properties and antibacterial activity. The unique Poly (vinylpyrrolidone) (PVP)-mTiO2 nanofiber air filter media acquired hydrophobic nature with a large increase in water contact angle of 127° from 36°. The resulting free-standing nanofiber filters exhibit high PM2.5 filtration efficiency of >99.9% and low pressure drop of 39 Pa. Antibacterial activity of nanofibrous membrane has been rationally engineered by titanium oxide as the barrier to bacterial ingression. A long term of 160 h filtration test has proved PVP-mTiO2 nanofibers air filter media holds outstanding 99% filtration efficiency for PM2.5. This work takes forward a significant lead in design and production of high performance and very low pressure drop air filter media with a wide range of functional properties.