Eco-friendly chitosan@silver/plant fiber membranes for masks with thermal comfortability and self-sterilization

The surgical masks have been essential consumables for public in the COVID-19 pandemic. However, long-time wearing masks will make wearers feel uncomfortable and massive discarded non-biodegradable masks lead to a heavy burden on our environment. In this paper, we adopt degradable chitosan@silver (CS@Ag) core–shell fibers and plant fibers to prepare an eco-friendly mask with excellent thermal comfort, self-sterilization, and antiviral effects. The thermal network of CS@Ag core–shell fibers highly improves the in-plane thermal conductivity of masks, which is 4.45 times higher than that of commercial masks. Because of the electrical conductivity of Ag, the fabricated mask can be electrically heated to warm the wearer in a cold environment and disinfect COVID-19 facilely at room temperature. Meanwhile, the in-situ reduced silver nanoparticles (AgNPs) endow the mask with superior antibacterial properties. Therefore, this mask shows a great potential to address the urgent need for a thermally comfortable, antibacterial, antiviral, and eco-friendly mask.

Graphical abstract

     

日常使用方式对一次性医用口罩微观结构和过滤效率的影响

The global spread of Corona Virus Disease 2019 (COVID-19) makes face masks become common protective equipment for daily life. This paper introduces the protection mechanism of disposable medical face masks, and investigates the changes of microstructure and filtration efficiency of disposable medical face masks after use and disinfection. It is helpful to get more understanding about protective effect of face masks.     

Personalized Reusable Face Masks with Smart Nano-Assisted Destruction of Pathogens for COVID-19: A Visionary Road

The Coronavirus disease 2019 (COVID-19) emergency has demonstrated that the utilization of face masks plays a critical role in limiting the outbreak. Healthcare professionals utilize masks all day long without replacing them very frequently, thus representing a source of cross-infection for patients and themselves. Nanotechnology is a powerful tool with the capability to produce nanomaterials with unique physicochemical and antipathogen properties. Here, how to realize non-disposable and highly comfortable respirators with light-triggered self-disinfection ability by bridging bioactive nanofiber properties and stimuli-responsive nanomaterials is outlined. The visionary road highlighted in this Concept is based on the possibility of developing a new generation of masks based on multifunctional membranes where the presence of nanoclusters and plasmonic nanoparticles arranged in a hierarchical structure enables the realization of a chemically driven and on-demand antipathogen activities. Multilayer electrospun membranes have the ability to dissipate humidity present within the mask, enhancing the wearability and usability. The photothermal disinfected membrane is the core of these 3D printed and reusable masks with moisture pump capability. Personalized face masks with smart nano-assisted destruction of pathogens will bring enormous advantages to the entire global community, especially for front-line personnel, and will open up great opportunities for innovative medical applications.     

小口罩博物馆奇遇记

Masks have played an important role in the fight against COVID-19. This paper introduces the knowledge of melt blown fabric and non-woven fabric related to mask by means of personification, and the relationship between melt index and product quality. Readers can understand the knowledge of polymer chemistry related to masks in interesting reading.     

Face mask-derived Ni,N-doped graphene sheets for electrocatalytic CO2-to-CO reduction

Journal of Solid State Electrochemistry - The COVID-19 pandemic that is still prevalent around the globe each day consumes massive disposable face masks and consequently lays a heavy burden on...     

Inhaled aerosols: Their role in COVID-19 transmission,including biophysical interactions in the lungs

The high rate of spreading of COVID-19 is attributed to airborne particles exhaled by infected but often asymptomatic individuals. In this review, the role of aerosols in SARS-CoV-2 coronavirus transmission is discussed from the biophysical perspective. The essential properties of the coronavirus virus transported inside aerosol droplets, their successive inhalation, and size-dependent deposition in the respiratory system are highlighted. The importance of face covers (respirators and masks) in the reduction of aerosol spreading is analyzed. Finally, the discussion of the physicochemical phenomena of the coronavirus entering the surface of lung liquids (bronchial mucus and pulmonary surfactant) is presented with a focus on a possible role of interfacial phenomena in pulmonary alveoli. Information given in this review should be important in understanding the essential biophysical conditions of COVID-19 infection via aerosol route as a prerequisite for effective strategies of respiratory tract protection, and possibly, indications for future treatments of the disease.     

化学教学新课堂：科学抗疫中的化学知识

As the break out of COVID-19 epidemic, the prevention and control work was consequently carried out. Chemistry plays an important role in the white war. The structure of mask contains the knowledge of interfacial chemistry. The material of mask encompasses the knowledge of polymer chemistry. Nucleic acid test and COVID-19 vaccine research need the knowledge of biological chemistry. The sanitizers involve the knowledge of inorganic and organic chemistry. The knowledge of physical chemistry takes effect in daily hand washing with soap. Each drug against COVID-19 virus was a complex organic compound. All the above things can be taken as appropriate examples in chemistry teaching to display the charm of chemistry. Meanwhile, these examples help students to realize that chemistry works as a vital part in our lives and therefore active their motivation to study chemistry well.     

纳米材料在病毒大流行防治中的应用

The novel coronavirus disease 2019 (COVID-19) pandemic has enabled scientists around the world to work on the areas such as prevention of virus spread, virus inactivation, and vaccine preparation. Based on the development of nanotechnology, the emergence of some nanomaterials provides some excellent solutions to overcome the virus pandemic: by spraying nano-coating, the masks and protective clothing in medical institutions can be self-sterilized; by adding nano-adjuvants, vaccines can produce stronger responses to antigen of lower doses; by wrapping with nanocarriers, drugs can escape the monitoring of the immune system so as to obtain better antiviral effects. The unique chemical properties of some nanomaterials indicate the broad prospects in future applications. In conclusion, nanomaterials will play an important role in combating COVID-19 and the future anti-viral pandemics.     

The effect of photomask resolution on separation efficiency on microfabricated devices

Separation quality on glass microfluidic devices fabricated from photomasks of different optical resolutions was compared by measuring the dispersion (apparent diffusion) coefficients of a set of standard compounds separated on these devices. Currently, the channel manifolds of most microfluidic devices are patterned using chrome photomasks. A much cheaper, more robust alternative to chrome photomasks are laser photoplotted masks. The primary disadvantage to using laser photoplots is that the optical resolution of these masks is not as high as that of chrome masks, and this feature increases the side-wall roughness of etched channel manifolds patterned using such masks. The increased wall roughness may affect the fluid flow within the channels and, therefore, the separation quality. To determine the effect of increased sidewall channel roughness, microchip channel manifolds were patterned in soda lime glass using a chrome photomask and laser photoplots printed at resolutions of 620, 1240, 3100 and 6200 dots per centimetre (dpc). Separations were performed on these devices using dilute solutions of fluorescently labeled amino acids. The peak variances of the amino acids were calculated at increasing distances down the separation channel and plotted as a function of migration time. From this plot, dispersion coefficients of the analytes were measured. This allowed for a reliable, relatively easy, direct separation analysis among microchips fabricated from the various photomasks. After multiple separations using microchips fabricated from each resolution mask, we found that the change in sidewall surface roughness did not significantly affect the dispersion coefficients measured, and thus the separation quality. The lower mask resolution limit, rather, was governed by the fidelity to which the mask could capture the original CAD design.     

面膜中微量元素的ICP-MS定量方法及其吸收率研究

以5种面膜为研究对象,采用电感耦合等离子体质谱技术,通过外标法对面膜中的12种微量元素进行定量分析,建立了敷面膜时间与微量元素含量的关系曲线,探究面部皮肤对微量元素的吸收率。结果表明:5种面膜中均检出的微量元素含量由高到低为Al、Sn、Fe、Zn、Hg,含量为0.027~5.209 mg/kg;人体面部皮肤对Se、Zn和Fe的吸收率较高,对Sn、Al的吸收率较低。该定量方法简单、快速、准确可靠,可为面膜中微量元素的研究及面膜的安全有效使用提供实验依据。     

Algae-Derived Bioactive Molecules for the Potential Treatment of SARS-CoV-2

The recently emerged COVID-19 disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has adversely affected the whole world. As a significant public health threat, it has spread worldwide. Scientists and global health experts are collaborating to find and execute speedy diagnostics, robust and highly effective vaccines, and therapeutic techniques to tackle COVID-19. The ocean is an immense source of biologically active molecules and/or compounds with antiviral-associated biopharmaceutical and immunostimulatory attributes. Some specific algae-derived molecules can be used to produce antibodies and vaccines to treat the COVID-19 disease. Algae have successfully synthesized several metabolites as natural defense compounds that enable them to survive under extreme environments. Several algae-derived bioactive molecules and/or compounds can be used against many diseases, including microbial and viral infections. Moreover, some algae species can also improve immunity and suppress human viral activity. Therefore, they may be recommended for use as a preventive remedy against COVID-19. Considering the above critiques and unique attributes, herein, we aimed to systematically assess algae-derived, biologically active molecules that could be used against this disease by looking at their natural sources, mechanisms of action, and prior pharmacological uses. This review also serves as a starting point for this research area to accelerate the establishment of anti-SARS-CoV-2 bioproducts.     

从化学视角浅谈医用口罩的重复利用

This paper briefly introduced the classification of disposal face masks, and the composition and structure of key protective layer, in addition to its protection principle. The feasibility of reuse and disinfection of the disposable face masks with several common medical methods is discussed based on the physical structure and chemical composition of meltblown, the main protective layer, in addition to biochemical characteristics of new coronavirus.     

Fabrication of heterogeneous binary arrays of nanoparticles via colloidal lithography

Heterogeneous binary arrays of metallic nanoparticles have been constructed by consecutively depositing gold and silver into monolayers of hexagonally close-packed latex spheres at the incidence angles of 15 and -15 degrees, followed by removal of the colloidal masks. The present approach is independent of the chemical nature of both colloidal masks and deposition materials. The pattern feature of the resulting binary nanoparticle arrays is dependent on the colloidal mask registry.     

用于抗新型冠状病毒的无机表面材料及其作用机制

由新型冠状病毒所导致的新冠肺炎疫情已对人类健康造成严重威胁, 病毒的大范围传播增加了对抗病毒表面材料(尤其是用于公共场所中)的需求. 本文综述了一系列具有抗病毒性能的无机表面材料, 包括金属单质及其衍生物、 石墨烯及其衍生物和沸石, 以及它们各自的抗病毒机制; 最后, 对无机抗病毒表面材料领域所面临的挑战与发展前景进行了总结与展望.     

Heat-transference of toner masks onto conductive substrates: A rapid and easy way to produce microelectrode ensembles

A novel and simple method for fabrication of microelectrode ensembles is reported. This procedure is based on the heat-transference of toner masks onto conductive substrates such as gold, platinum, and glassy carbon. The percentage of printed toner masks was controlled by using a suitable graphic software. The heat transference of 100% black toner mask onto a conductive substrate isolated electrically its whole surface, in such a way no electrochemical response was established using the modified substrate. However, when the same substrates were coated with 99% black toner mask, few naked micro-areas of the conductive material were identified. Such modified substrate presented typical electrochemical behavior of microelectrode ensembles, which evinced the presence of exposed micro-areas of substrate to the bulk solution. Different percentages of coverage were evaluated and the microelectrode ensembles were characterized by cyclic voltammetry with good agreement with the established theory. Stripping voltammetry of metals was also performed demonstrating the successful application of these new ensembles in accordance with characteristics normally presented by microelectrodes. The main advantages of this new procedure are the simplicity, low-cost of equipments (LaserJet printer and thermal press equipment), and the high speed of production of microelectrode arrays on different substrates.     

新型冠状病毒疫苗设计原理与研究进展

The COVID-19 pandemic caused significant losses to the global community. The pathogen, called SARSCoV-2, showed high infection rate and certain case-fatality rate, which bring great challenges to treatments. Vaccination is the major way for epidemic prevention which attracts several developers to conduct COVID-19 vaccine studies. This paper presents the design principle of a COVID-19 vaccine and summarizes the latest research progress on vaccine development. The authors hope to provide insights for understanding vaccine study of COVID-19.     

“新冠肺炎”抗疫中使用的重要高分子材料

Polymeric materials played an important role in the battle against novel corona virus epidemic. These materials can be seen everywhere not only from the conventional protective masks to professional protective equipment, but also from the expensive extracorporeal membrane oxygenation (ECMO) to the rapid construction of the Huoshenshan and Leishenshan Hospital. In this paper, the synthesis, processing and manufacture of these polymeric materials are introduced from the viewpoint of polymer chemistry, polymer physics and polymer processing, with emphasis on the important role of these materials in the battle against the COVID-19 epidemic.     

The Influence of Propolis on Dental Plaque Reduction and the Correlation between Dental Plaque and Severity of COVID-19 Complications—A Literature Review

Current studies suggest that cariogenic bacteria in dental plaque influence the severity of COVID-19 complications since the oral cavity is a reservoir for respiratory pathogens potentially responsible for the development of hospital-acquired pneumonia. This article focuses on the association between dental plaque and COVID-19 concerning the influence of altered oral biofilm on the risk of increased severity of SARS-CoV-2 infection. Moreover, it concentrates on the usefulness of propolis, with its apitherapeutic antibacterial properties, for treating oral bacterial infections co-occurring with SARS-CoV-2 infection. A review of the literature on PubMed, Cochrane Library and Medline between 2000 and 2021 revealed 56 published articles indicating that a link between dental plaque and COVID-19 complications was probable. Furthermore, they indicated that propolis may minimize COVID-19 severity by reducing dental plaque accumulation. The possibility that improved oral health could reduce the risk of COVID-19 complications should be of interest to scientists.