GUWAHATI: Researchers at the Indian Institute of Technology-Guwahati (IIT-Guwahati), have developed a Silica Nanoparticles coated cotton fabric that can separate oil from oil-water mixture.

The research aims to convert a large-scale agricultural waste into a sustainable value-added product to mitigate marine oil pollution.

The nanoparticles have been developed by utilising rice husk, an agricultural waste, as the primary source material.

The findings of the study can aid in development of economical, sustainable platforms for separating oil and water mixtures or harmful components from aqueous and non-aqueous mixture.

Oil spills due to industrial discharge or accidental mishap causes irreversible damage to the aquatic ecosystems.

Conventional cleaning techniques including skimming, or in-situ burning is ineffective, costly and causes additional pollution.

Researchers around the world have been trying to develop energy efficient materials to separate the oil and water mixtures.

However, the sustainable and economically viable conversion of biomass to modified silica for oil spill mitigation had not been explored earlier.

Explaining the eco-friendly method Prof Vaibhav V Goud of the department of chemical engineering, IIT Guwahati, said, “Our technology has multiple beneficial effects on the environment. Rice husk is an agricultural byproduct and rich in silica that is generated in millions of tons every year. It generally ends up being burnt unscientifically causing air pollution. With our technique, this waste rice husk is converted to 3D sorbents that mitigates oil contamination by following a selective active-filtration process.”

“In this process, rice husk, which is an inexpensive agricultural-waste, is gradually heated and efficiently converted to charcoal. Subsequently, this charcoal is subjected to further heating to transform it to silica nanoparticles. The size of these nanoparticles can be customized by adjusting the pH of the charcoal. To render the nanoparticles water-repellent, they are treated with special chemicals known as silanes. Finally these treated nanoparticles are coated over a cotton material creating a natural and three-dimensional sorbent for separating oil-water mixture,” Prof Goud added.

Explaining the significance of their work, Prof Goud further said, “Our experiments at IIT Guwahati have demonstrated that the coated cotton fabric particularly adsorbed oil, while the uncoated sample adsorbed both oil and water. The developed superhydrophobic material has shown a remarkable 98 per cent efficiency and retained its functionality even after repeated use and exposure to harsh environments.”