Graphene masks cost as little as $ 0.05! Not only can self-cleaning, but also for seawater desalination

石墨烯口罩成本低至0.05美元!不仅可以自清洁,还能用来海水淡化 2019 coronavirus (COVID-19) affects more than 210 countries and regions, and mainly through respiratory droplets. In high-risk areas, patients, doctors and even ordinary people are generally the use of disposable surgical masks. However, the current ordinary surgical masks presence not self-disinfecting, reused or recycled for other uses and other issues. To deal with these used masks, most countries can only be used to deal with such medical waste incineration. Of toxic gases and carbon emissions would seriously harm the environment. So the question is, how the new mask design? For this reason, The Hong Kong Polytechnic University, Li Guijun Task Force proposed a unique approach to treatment of commercially available masks functional, has excellent self-cleaning optical and thermal properties . Researchers dual-mode laser-induced forward transfer method The low melting point to multi-graphene deposited on the nonwoven fabric prepared mask – a mask graphene. related to the outcome of \”Reusable and Recyclable Graphene Masks with Outstanding Superhydrophobic and Photothermal Performances\” published in top international journals ACS nano .

Figure 1 a schematic view of a graphene mask

and then compared to a typical commercial masks, masks graphene which has excellent performance?

1 self-cleaning property (surface-hydrophobic)

Figure 2. Physical characterization and hydrophobic graphene coating

on the microstructure and physical properties of graphene laser transfer system were characterized. Observation of the microstructure of the coating material with a scanning electron microscope, the fiber surface can be observed nanostructures sheet, in order to determine the chemical composition of these nano-sheets, the use of Raman spectroscopy clearly showed the presence of graphene. The 2D location of the peak and the peak relative to the peak intensity ratio D, the coating may be determined as few-layer graphene. Most commercial general surgical maskDivision is made by meltblown polymers which are randomly distributed meltblown fibers. Lack of nanostructures, the fiber surfaces are smooth thus lack superhydrophobic properties. The graphene surface of the mask can observe water droplets move freely, without leaving any trace. Thus, the graphene superhydrophobic coating excellent in performance can be significantly improved self-cleaning property of the droplets.

2. Reusability (self-sterilizing)

Low ordinary commercial masks absorption of solar spectrum, especially in the visible and near-infrared region. Graphene mask and showed over 95% absorption rate in the whole solar spectrum of 300 ~ 2500 nm. Since spike proteins on COVID-19 temperature sensitive virus, thus giving photothermal graphene coating masks the potential to self-sterilizing. Experiments show that the ordinary solar radiation masks 5 minutes after the temperature below 45 ℃. Rapid increase contrast, the surface temperature of the graphene irradiation mask 40 s after the sun to over 70 ° C, 100 s after the sun maintained at 80 ° C, which is related to the thermal properties superior light graphene . The virus disinfection information more than 70 ° C a temperature sufficient to inactivate most types of virus.

Figure 3. The photo-thermal properties of graphene mask

3. Recyclability (desalination)

when the virus disappeared from the earth, the graphene masks also have great potential to be recovered for other uses. Due to its excellent optical and thermal properties of the porous structure, it can be directly used as a solar steam generator. Graphene masks reached the solar steam generation rate per hour 1.13 kg / square meter, although the value is lower than the amount of evaporation of the latest research report, but small-scale use of solar energy for desalination of sea water is sufficient, much higher than the original masks (only 0.3 kg / square meter). At the same time, this graphene masks exhibit in desalination excellent long-term stability and salt function. When the evaporation of brine 10%, compared with the polyimide film solar steam generator, mask graphene showed significant better performance of salt, because the microporous fiber can help microscale the salt was dissolved in a better channel. Graphene surface of the mask was no significant accumulation of salts, continuous evaporation 100 h, the steam generation rate stabilized at 1 kg / square meter toon. This indicates that graphene masks for long-term desalination technology is feasible.

Figure 4. graphene solar steam generation performance of the mask


By this manufacturing mode laser scribing mask graphene coating exhibits excellent thermal properties and optical super-hydrophobic, can also be used in small desalination, has tremendous potential reusable and recyclable. The key is very low cost, the cost of each graphene masks is estimated at $ 0.05, can be mass produced. Therefore, these reusable and recyclable masks can provide economic, environmental solutions, and to fight raging COVID-19 virus pandemic to provide better protection. References: Reusable and Recyclable Graphene Masks with Outstanding Superhydrophobic and Photothermal Performances, ACS Nano, 2020 DOI: 10.1021 / acsnano.0c02250 full text link: https: //