Plasmonic and Superhydrophobic Self-Decontaminating N95 Respirators.

The COVID-19 pandemic is endangering the world due to the spread of respiration droplets with viruses. Medical workers and frontline staff need to wear respirators to protect themselves from breathing in the virus-containing respiration droplets. The most frequently used state-of-the-art respirators are of N95 standard; however, they lack self-decontamination capabilities. In addition, the viruses and bacteria can accumulate on the respirator surfaces, possessing high risks to the wearers over long-term usage. Photothermal decontamination is a contactless, fast, low-cost, and widely available method, capable of decontaminating the respirators. Herein, we report a plasmonic photothermal and superhydrophobic coating on N95 respirators, possessing significantly better protection than existing personal protection equipment. The plasmonic heating can raise the surface temperature to over 80 °C for this type of respirator within 1 min of sunlight illumination. The superhydrophobic features prohibit respiration droplets from accumulating on the respirator surfaces. The presence of the silver nanoparticles can provide additional protection via the silver ion's disinfection toward microbes. These synergistic features of the composite coatings provide the N95 respirator with better protection and can inspire experts from interdisciplinary fields to develop better personal protection equipment to fight the COVID-19 pandemic.

Reusable and Recyclable Graphene Masks with Outstanding Superhydrophobic and Photothermal Performances.

The 2019 coronavirus outbreak (COVID-19) is affecting over 210 countries and territories, and it is spreading mainly by respiratory droplets. The use of disposable surgical masks is common for patients, doctors, and even the general public in highly risky areas. However, the current surgical masks cannot self-sterilize in order to reuse or be recycled for other applications. The resulting high economic and environmental costs are further damaging societies worldwide. Herein, we reported a unique method for functionalizing commercially available surgical masks with outstanding self-cleaning and photothermal properties. A dual-mode laser-induced forward transfer method was developed for depositing few-layer graphene onto low-melting temperature nonwoven masks. Superhydrophobic states were observed on the treated masks' surfaces, which can cause the incoming aqueous droplets to bounce off. Under sunlight illumination, the surface temperature of the functional mask can quickly increase to over 80 °C, making the masks reusable after sunlight sterilization. In addition, this graphene-coated mask can be recycled directly for use in solar-driven desalination with outstanding salt-rejection performance for long-term use. These roll-to-roll production-line-compatible masks can provide us with better protection against this severe virus. The environment can also benefit from the direct recycling of these masks, which can be used for desalinating seawater.