This coating made from rice husk, by Shiv Nadar University, can save India's monuments from corrosion

Several studies concerning the effect of air pollution have indicated that removing atmospheric corrosion on surfaces like buildings, monuments, railings, and a lot of other industrial components, is costly. Studies have also indicated that the global cost of corrosion is around US $2.5 trillion, which is equivalent to 3.4 per cent of the global GDP. In order to solve this problem, a team of researchers at Shiv Nadar University in Uttar Pradesh has invented a unique super-hydrophobic (water-repelling) coating that can help eliminate discoloration of the surface, physical damage or corrosion on a long-term basis.

Developed by extracting the nano-silica particles of rice husk — an agriculture waste product, it also has the potential to offer an alternative to crop residue burning by farmers, a major cause for air pollution in the northern part of the country. The self-cleaning coating is cost-effective, eco-friendly and thus the apt substitute for the existing toxic paints and coatings already available in the market. Inspired by the super-hydrophobic nature of the lotus leaves, the coating has been developed by Dr Harpreet Singh Grewal, Dr Harpreet Arora, Associate Professors, and their research team at the varsity's School of Engineering. This research has been published by the prestigious and specialised scientific journal, Progress in Organic Coatings.

Dust is hydrophilic in nature which means it is water-loving, so this coating is hydrophobic and thus it will not let the dust stick to the surface. Regular rains or acid rain due to air pollution will also not affect the surfaces and thus decrease corrosion. It can be used to protect various other surfaces and things around us. For example: the exhaust fans in our houses — oil coming from the kitchen, this coating will stop the oil and dust particles from depositing in that area, thus helping keep the fan clean and prevent it from getting corroded. Also, using this coating is way more economical as we are converting an agricultural waste product into a high-value product. It can also save water as one doesn't have to clean the dust with the help of large amounts of water

Dr Harpreet Singh Grewal, Associate Professor

The research has been sponsored by the Government of India’s Council of Scientific and Industrial Research (CSIR), and has been tested under extreme weather conditions including rain and storms. "Results of the research indicate that the exposure to outdoor conditions has no impact on the coating.  Another important feature of the coating is that it is non-toxic and can be applied on all household appliances, buildings, automobiles and industrial components to help elongate their life. The existing paints and coatings available in the market contain toxic elements like lead, hexavalent chromium or chemical compounds which cause serious health effects, such as reproductive problems, birth defects, and aggravated asthma due to air pollution," the researcher adds.

Highlighting the importance of this invention coming out of agricultural waste, Dr Rupamanjari Ghosh, the varsity's Vice-Chancellor, said, "Dust and corrosion have a detrimental impact on the industrial and mechanical operations especially in regions that deal with the problem of heightened air pollution. Excessive corrosion leads to unnecessary wear-and-tear of machines and devices, reducing their efficacy and functional life. It is extremely rewarding, therefore, to see researchers at the Shiv Nadar University find a creative and sustainable solution to this wide-spread problem."