Prof T Pradeep with the first author of the paper, BS Spoorthi. (Photo Courtesy IIT-Madras)
Soil is ubiquitous. It is seen everywhere and life on earth depends on it. But how is soil formed? Researchers from the Indian Institute of Technology-Madras in Chennai have now provided clues on how minerals and small rock particles get broken into nano particles, which is what soil is.
Soil is formed by the weathering of rocks as they roll in streams and rivers -- a very long process requiring hundreds of years. It is friction at the river-bed or ocean-bed that breaks the rocks down. But not to the extent of nano-particles. They are formed purely by chemical reaction, researchers from IIT-Madras have found.
The work of Prof Thalappil Pradeep and his team of six researchers has been published in the highly regarded American journal "Science". The institution proudly asserted this is its first research paper to be published in "Science". The 144-year-old magazine is published by the American Association for the Advancement of Science (AAAS), where some of the best research gets published.
The experiment by Prof Pradeep's team proved that particles of coarse river sand, ruby and alumina, which are very hard minerals, get incorporated in tiny charged water droplets and break spontaneously to form nanoparticles, in milliseconds.
The occurrence was replicated in laboratory experiments. "We deciphered how 'water droplets break down hard gems'," said Prof Pradeep, a highly regarded researcher working to understand the many facets of the water molecule.
"The science we reported, if it happens in nature, could be a very important way to transform rocks to natural nanoparticles, which are active ingredients of soil. To put it bluntly, we have found a way to make sand to soil. Looking into the future, I might say that with adequate resources, we can help deserts bloom," he said.
In a statement, the research team said: "This rapid process of weathering may be important for soil formation, given the prevalence of charged aerosols in atmosphere. Soil forms through rock weathering, a process involving multiple factors and it takes 200-400 years to yield one centimetre of it normally, composed of varied particle sizes. Nanoparticles of minerals such as silica are crucial for the growth of crops such as rice and wheat."
Co-researcher Prof. Umesh V. Waghmare, who works at the Theoretical Sciences Unit at Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, and is the President of the Indian Academy of Sciences, said, "The phenomenon involves complex processes inherent to micro-droplets of water, and understanding its mechanism will stimulate many fundamental scientific studies."
Dr BK Spoorthi, the lead research student who has just completed her PhD from IIT Madras, said: "This finding offers a transformative technique for soil formation, dramatically accelerating natural weathering processes from centuries to moments. Beyond its environmental benefits, this method advances nanotechnology and materials science, enabling sustainable and efficient nanoparticle production with broad industrial applications".
Commenting on the future possibilities of this research, Dr R Graham Cooks, Department of Chemistry, Purdue University, USA, questioned in an accompanying insight piece if the fresh understanding can be used to "improve battery performance" -- the holy grail for researchers as electric vehicles and solar energy take centrestage.