Inspired by nature
If you took a long, hard look at the gemsbok, would you ask how this animal – which traverses the deserts of the Kgalagadi – could change the way in which human beings minimise their impact on the planet? Probably not. But this was the question asked by Professor Malik Maaza, a nanoscientist and holder of the UNESCO Africa Chair in Nanosciences and Nanotechnology at UNISA – and answered by his development of thermochromic intelligent nanocoating for smart glass windows using vanadium oxide innovation. Simply put, Maaza’s research can potentially minimise the energy load caused by air conditioning and energy use, thanks to his in-depth research into one of the hardiest buck species in Africa, the gemsbok.
“Air conditioning consumes a lot of energy and it just isn’t green,” says Maaza. “In a car alone, you are consuming 17% to 24% of your fuel when you activate the aircon. We set out to find a solution to the problem, and the solution was vanadium oxide. This material transmits infrared radiations (heat) from the sun during winter and reflects them back in summer – it is solar heat transmissive and solar heat opaque when it is cold and hot respectively, allowing direct heat and air conditioning through the window.”
The gemsbok can go without water for weeks because it can control the heat of its skin, adjusting its consumption of air during the day and the night. The animal can adapt its oxygen consumption to match the temperature of the landscape that surrounds it. “Vanadium oxide has the ability to biomimic Mother Nature with a transition temperature that’s nearly the same as the gemsbok,” says Maaza. “Once we embarked on our research, we realised that the material generated a lot of interest, and so we set out on a larger mission: to find a way of making this coating big enough to cover wider surface areas such as skyscrapers’ windows.”
What adds even greater significance to the research conducted by Maaza into the potential of the mineral to change the green face of the planet, is that South Africa has the second largest vanadium deposits in the world after China. Should the project take off, there will be benefits to the local economy in terms of mineral beneficiation.
“The glass industry is huge, and some of the largest companies in the world have also started creating this coating,” says Maaza. “It’s a hot topic and, as we have one of the largest approved resources in the world, the effect that this industry could have on our sustainable development is huge. There are still challenges, but we are on the right path. Our motto, to quote Madiba, is: “It always seems impossible until it’s done.”
In addition to the work done with vanadium dioxide, Maaza has spent the past 25 years contributing to the development of technical innovation that’s both green and sustainable. He has prioritised green energy and green materials manufacturing, and has succeeded in positioning Africa on the global nano-stage. Some of the work he has done includes focusing on high-temperature, platinum-based selective solar absorbers and on a new generation of nanofluids, the green synthesis of multifunctional oxides for cosmetic and sanitary health applications, and plenty more.
“This field is multi-disciplinary – you can be a chemist, a physicist, a mathematician. There is always such a dynamic mix of skills,” concludes Maaza. “My goals are to make a difference with my colleagues at the South African Nanotechnology Initiative and to contribute to a sustainable society using the nanotechnology, skills and materials that South Africa and Africa have to offer.”