Breathable Breakthrough: Porphyrin-Based Nanosheet Filters Trap Viruses Without Blocking Airflow.

A team of researchers from the Institute of Industrial Science at the University of Tokyo has made a significant advancement in mask technology by developing a highly breathable filter that effectively captures virus-sized particles. Published this month in Materials Advances, their study addresses a long-standing issue in mask design: how to block tiny pathogens without compromising air flow and user comfort.

During the COVID-19 pandemic, the importance of effective face masks became widely recognized. Traditional masks with pores small enough to trap viruses—typically around 100 nanometers in size—often restrict airflow, leading to discomfort for users. The new research offers a promising solution to this problem.

The innovative filter is composed of nanosheets made from porphyrins, flat, ring-like molecules with central cavities. These molecules form an organized mesh that allows small gas molecules to pass through while preventing larger particles, such as viruses, from getting through. The nanosheets are layered onto a fabric base that has been modified with nanofibers, which contain pores several hundred nanometers wide. This structure supports the nanosheets and contributes to the overall filtration effectiveness.

"The porphyrin-based nanosheets are formed via interfacial reactions driven by the movement of reactants caused by surface tension gradients at the air–solvent boundary, a phenomenon known as the Marangoni effect," explained senior researcher Kazuyuki Ishii. The team then applied a compression and stamping technique to coat the nanosheets onto the nanofiber-modified fabric.

To evaluate the performance of their design, the researchers used standard testing methods for N95 face masks. Their filter achieved a 96% particle filtration efficiency, surpassing the 95% threshold required for N95 certification. Moreover, the filter maintained a low differential pressure during gas flow testing, indicating minimal airflow resistance.

"Our filter effectively captured nanoparticles as small as 100 nanometers," Ishii said. "More importantly, it did so without significantly impeding airflow. This shows our design can provide both protection and comfort."

This approach of integrating porous nanosheets with nanofiber-enhanced fabrics could pave the way for next-generation personal protective equipment that doesn’t force users to choose between safety and breathability.

Source:https://phys.org/news/2025-05-mask-users-easily-porphyrin-based.html

This is non-financial/medical advice and made using AI so could be wrong.