Nanomaterials for Cooling

Small changes can have very large effects. Even if “small” happens to be in the realm of nanometers, it can have effects powerful enough to transform the way we live and consume energy.

Subhashini, Rashmi, and Shreya, three researchers who work in the Alternate Energy and Nanotechnology Lab, in the Physics department of IIT Madras under the supervision of Prof. Ramaprabhu, have been working on the development of alternate energy systems using nanotechnology. With a shared commitment to develop clean energy, they have caught the eye of industry and academia alike with their recent research involving carbon nanotubes.

Nanomaterials are structures of the size of a few nanometres – a nanometre is a billionth of a metre – which has excited the scientific community for long because of the variety of ways in which they can alter the properties of other materials.

The most popular of these are carbon nanotubes and graphene, both of which, though allotropes of carbon, differ in their molecular structure. These nanomaterials can do wonders when mixed (dispersed) in a medium which is a combination of base fluids and solvent.Prof. Ramaprabhu’s research group has successfully used nanomaterials to increase the thermal efficiency of such a medium. This has applications in industry, where it can be used for cooling purposes.

The research group manufactured the carbon nanotubes, “functionalised” them to increase their dispersion ability and finally combined them with base fluids to do a thorough analysis. Their success has led to widespread acknowledgement of their work, with TATA Steel signing a Memorandum of Understanding with IIT Madras.

The technology needs to be developed further to reach its usable form, as producing carbon nanotubes is expensive, costing about Rs. 2500 for every gram. Meanwhile, industries are investing heavily in their research divisions to develop cheaper ways of producing carbon nanotubes. Prof. Ramaprabhu estimates that it would take another five to ten years for carbon-nanotube-based solutions to replace common heat exchanger fluids and coolants, and microchip coolant coatings. The pace of development, of course, depends on quality research work being done by research groups like the one here at IIT-M.