Pump-inject antimicrobial and biodegradable aerogel as mask intermediate filter layer for medical protection of air filtration

Melt-blown fabric masks have the drawbacks of the supply-demand imbalance, the risks of respirable infection, and environmental pollution. Therefore, it is urgently needed to exploit a new mask material with excellent air-filtration, antimicrobial, and degradable properties. In this study, a new sodium alginate (SA)/nanosilver composite mask intermediate filter layer (named as SAg air filter) is prepared by a simple and quantifiable pumping-injecting method to substitute the traditional melt-blown fabric. Subsequently, the prepared SAg air filter is softened with glycerol solution to improve the flexibility. Compared with the intermediate filter layer of the melt-blown fabric mask, the SAg air filter has more excellent performances, such as environmental friendliness, degradability, large-scale preparation, stable and long-lasting air filtration, good impermeability, as well as suitable breathability. What's more, the air filter combines physical and mechanical filtration, Coulomb adsorption of nano-silver, and antimicrobial air purification through the SAg aerogel network to ensure more comprehensive air purification and filtration. The novel SAg air filter will have a broad application prospect in the mask market, and eventually extend the new application of SA aerogel in the air filtration field.