GUWAHATI, Nov 29: Researchers at the Indian Institute of Technology-Guwahati (IIT-G) have developed a ‘nanometer thick superhydrophobic coating’ material to modify ordinary cloth or silk masks that maintain its comfort but offer better protection against aerosol-driven infections such as COVID-19.
According to World Health Organisation (WHO) guidelines, N95 masks or double masking protects people to a great extent from coronavirus. But the drawback is that people undergo suffocation after wearing them for a long time.
“To address these challenges and to bring in a safer, economical and comfortable alternative, the researchers 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 a longer period of time,” a statement issued by IIT-G here on Monday said.
“Another advantage is that these masks are versatile and can be used with other additives such as antibacterial nanomaterial for additional protection against viruses,” it said..
The research was led by Prof. Arun Chattopadhyay, department of chemistry and Centre for Nanotechnology, IIT-G and Partho S. G. Pattader, department of chemical engineering, School of Health Science and Technology, and Centre for Nanotechnology, IIT-G.
The work was recently published in the peer-reviewed journal, ACS Applied Bio Materials.
Highlighting the unique aspects of the research, Prof. Chattopadhyaysaid, “A cloth mask is largely porous to aerosols and thus cannot effectively prevent COVID-19 type infections. Although they are still better than wearing no mask, an improved version that would prevent the entry or exit of the aerosols from the modified cloth mask was needed.”
The breathability was tested by measuring the oxygen permeation through the mask with the help of an instrument called gas chromatography.
Shedding light on the use of eri silk, Prerona Gogoi, student, department of chemical engineering, IIT-G, and the first author of the paper, said, “We have chosen eri silk for carrying out this study. This silk comes from the caterpillar, samia ricini, native to Northeast India and some parts of China and Japan.”
“This is a one-step quick and inexpensive fabrication process that would help in the mass production and distribution of these masks to a large section of the population,” Gogoi added.
The sustainable, durable, and robust eri silk is softer than other silk or cotton and has the unique property of maintaining coolness in summer and providing warmth in winter.
Describing the functioning of the mask, Pattader said, “To attain hydrophobicity, the eri silk fabric was coated with a biocompatible nanometer-thick coating of a chemical called octadecyl trichlorosilane (OTS). OTS, being a fluorine-free chemical after bonding with the fabric, becomes non-hazardous to health and the environment.”