New Mask technology effectively balances protection and comfort

New Mask technology effectively balances protection and comfort

The Covid-19 pandemic has increased public awareness of the importance of mask use for personal protection. However, when the mesh size of the mask fabrics is small enough to capture viruses, which are usually around a hundred nanometers in size, the fabric usually also restricts air flow, resulting in user complaint. But now researchers from Japan have found a way to avoid this.

In a study published this month inMaterials advancesPresentResearchers at the Institute of Industrial Science, University of Tokyo, have overcome this bottleneck and developed a filter that can capture nanoparticles such as viruses without severely restricting air flow. They achieved this feat by carefully designing the pore structure in the filter.

The filter is made up of nanosheets made up of an ordered network made up of porphyrins, which are flat, ring-shaped molecules with a central hole. The tiny holes in the porphyrin molecules are suitable for allowing the easy passage of the small gas molecules in air while blocking the movement of larger particles such as viruses. The nanosheets are then supported on a nanofiber-modified fabric containing pores of several hundred nanometers to form the filter.

The porphyrin-based nanosheets are constructed through interfacial reactions driven by the movement of reactants caused by the surface tension gradient at the air-solvent interface, called the Marangoni effect. The nanosheets are then compressed using a postage stamp method and coated with nanofiber modified fabric. “

Kazuyuki Ishii, senior author

The team tested their filter using the standard procedure for testing N95 face masks. The results of the particle filtration tests showed that the filter effectively trapped particles as small as viruses. The filter achieved a particle filtration efficiency of 96%, exceeding the 95% requirement for an N95 face mask.

“Our porphyrin-based filter collected nanoparticles with a diameter of only one hundred nanometers,” explains Kazuyuki Ishii Kazuyuki. "Importantly, the filter also showed a minimal decrease in differential pressure during gas flow measurements. This shows that the filter is capable of trapping particles as low as viruses, while barely restricting airflow."

The team's approach, which involves coating porous nanosheets on nanofibers, shows promise in providing materials capable of effectively filtering small particles such as viruses while maintaining airflow to ensure both user comfort and protection.

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