Superlattice Nanofilm on a Touchscreen for Photoexcited Bacteria and Virus Killing by Tuning Electronic Defects in the Heterointerface.

Currently, the global COVID-19 pandemic has significantly increased the public attention toward the spread of pathogenic viruses and bacteria on various high-frequency touch surfaces. Developing a self-disinfecting coating on a touchscreen is an urgent and meaningful task. Superlattice materials are among the most promising photocatalysts owing to their efficient charge transfer in abundant heterointerfaces. However, excess electronic defects at the heterointerfaces result in the loss of substantial amounts of photogenerated charge carrier. In this study, a ZnOFe2 O3 superlattice nanofilm is designed via atomic layer deposition for photocatalytic bactericidal and virucidal touchscreen. Additionally, electronic defects in the superlattice heterointerface are engineered. Photogenerated electrons and holes will be rapidly separated and transferred into ZnO and Fe2 O3 across the heterointerfaces owing to the formation of ZnO, FeO, and ZnFe covalent bonds at the heterointerfaces, where ZnO and Fe2 O3 function as electronic donors and receptors, respectively. The high generation capacity of reactive oxygen species results in a high antibacterial and antiviral efficacy (>90%) even against drug-resistant bacteria and H1N1 viruses under simulated solar or low-power LED light irradiation. Meanwhile, this superlattice nanofilm on a touchscreen shows excellent light transmission (>90%), abrasion resistance (106 times the round-trip friction), and biocompatibility.

Amino‐terminated hyperbranched polymer functionalized graphene oxide with in situ trapped silver nanoparticles for high‐performance antibacterial nonwoven fabric

Antibacterial fabric with high thermal stability and mechanical strength is important for personalized protection, especially under the background of coronavirus pandemic (COVID‐19). This paper presents a facile approach toward high‐efficient antibacterial polypropylene spunbonded nonwoven fabrics (SNFs), which are decorated by a composite of graphene oxide embedded with silver nanoparticles (AgNPs/GO) through dip‐coating and in situ reduction effect of pre‐introduced amino‐terminated hyperbranched polymer (HBP‐NH2). Typically, HBP‐NH2 was grafted onto the GO nanosheets, then silver ions were trapped and self‐reduced by the HBP‐NH2 to generate silver nanoparticles decorated GO. The produced AgNPs are uniformly dispersed on the GO with a size of 13 nm. As an antibacterial coating, the Ag/GO composite could tightly wrap the SNFs fibers through the dip‐padding method, capable of enhancing the thermal stability and mechanical property of SNFs. The treated SNFs exhibited excellent antibacterial activities (~99.9%) against both Echerisia coli and Staphylococcus aureus, promising important potential for biomedical and personal protection applications.

Research proposal on architectural copper-based antimicrobic solutions in high traffic spaces

This contribution investigates research opportunities in the field of architecture and design management focusing on user health in high traffic spaces. The field of application is Airport Passenger Terminals. Looking at the COVID-19 pandemic and anticipating the possibility of events of the same magnitude, it is necessary to approach the problem of the safety in public spaces. Based on the State of the Art about antimicrobial material studies, Science of Architecture could propose innovative solutions that are compliant with health safety and prevention for high-use surfaces. These solutions will combine antimicrobial materials with a digital solution that could manage data about surfaces, allowing the maintenance team to valuate and optimize operations. After few hours the hygiene level of copper-based surfaces is higher than any other material. Copper-based furniture could be paired with sensors that send data to management software. Combining the use of scientifically demonstrated antibacterial surfaces with high-performance management tools could be the best option to achieve health safety and contribute to social sustainability. Airport terminals are the ideal high-traffic buildings to use as test model because they have all the characteristics that could be analysed concerning the safety and the perception of safety of architectural spaces by users.

Single-Side Superhydrophobicity in Si3N4-Doped and SiO2-Treated Polypropylene Nonwoven Webs with Antibacterial Activity.

Meltblown (MB) nonwovens as air filter materials have played an important role in protecting people from microbe infection in the COVID-19 pandemic. As the pandemic enters the third year in this current global event, it becomes more and more beneficial to develop more functional MB nonwovens with special surface selectivity as well as antibacterial activities. In this article, an antibacterial polypropylene MB nonwoven doped with nano silicon nitride (Si3N4), one of ceramic materials, was developed. With the introduction of Si3N4, both the average diameter of the fibers and the pore diameter and porosity of the nonwovens can be tailored. Moreover, the nonwovens having a single-side moisture transportation, which would be more comfortable in use for respirators or masks, was designed by imparting a hydrophobicity gradient through the single-side superhydrophobic finishing of reactive organic/inorganic silicon coprecipitation in situ. After a nano/micro structural SiO2 precipitation on one side of the fabric surfaces, the contact angles were up to 161.7° from 141.0° originally. The nonwovens were evaluated on antibacterial activity, the result of which indicated that they had a high antibacterial activity when the dosage of Si3N4 was 0.6 wt%. The bacteriostatic rate against E. coli and S. aureus was up to over 96%. Due to the nontoxicity and excellent antibacterial activity of Si3N4, this MB nonwovens are promising as a high-efficiency air filter material, particularly during the pandemic.