GUWAHATI: Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a ‘Nanometer Thick Superhydrophobic Coating’ material to modify ordinary cloth or silk masks to give better protection against COVID-19.
The masks will maintain its comfort but offer better protection against aerosol-driven infections such as COVID-19.
According to the World Health Organisation (WHO) guidelines, N95 masks or double masking protects people to a great extent from coronavirus. However, people undergo suffocation after wearing them for a longer period of time. Besides, N95 is costly and thus unaffordable to large sections of the population. As such, most people are seen resorting to cheaper and readily-available cloth and silk masks.
To address these challenges and bring in a safer, economical and comfortable alternative, the researchers of IIT Guwahati have developed a coating material to modify the easily-available cloth mask into a hydrophobic mask to repel virus-laden droplets and avoid breathing difficulties even when worn for long time.
The research was led by Prof. Arun Chattopadhyay, Department of Chemistry and Centre for Nanotechnology, IIT Guwahati and Dr. Partho S. G. Pattader, Department of Chemical Engineering, School of Health Science and Technology, and Centre for Nanotechnology, IIT Guwahati.
Highlighting the unique aspects of this research, Prof. Arun Chattopadhyay said, “A cloth mask is largely porous to aerosol and thus cannot effectively prevent COVID-19 type infection. Although they are still better than wearing no mask, an improved version that would prevent the entry or exit of the aerosol from the modified cloth mask was needed. We have worked on that based on the principle of repulsion of the aerosol by the modified cloth while allowing the air to flow through the mask. A simple coating of the hydrophobic molecule on the silk cloth worked well here.”
The breathability was tested by measuring the oxygen permeation through the mask with the help of an instrument called Gas Chromatography. The penetration of oxygen reduces by only 22 percent for the modified Eri silk mask compared to the natural Eri silk mask, whereas for N95, the reduction with respect to the natural Eri silk came out to be around 59 percent. The modified silk mask was found to be way more breathable than the N95 mask but with almost similar protection against aerosol-driven infections.
The sustainable, durable, and robust Eri silk, also referred to as the fabric of peace, is softer than many other silks or cotton, and has the unique property of maintaining coolness in summer and providing warmth in winter.
When any droplet hits the modified Eri silk mask, it bounces back into the air rather than being passed through the fabric or getting soaked by the fabric itself. These modified Eri silk masks can be reused again after subsequent washing with household detergent and drying.