(please note this article is from an interview undertaken in 2022)
A Fine Balance: A/Professor Koshy.
An innovator using waste materials for a sustainable project.
Dr. Koshy, an Associate Professor at the School of Materials Science and Engineering at UNSW. His students and fellow researchers look at chemical components and structure of materials. Posing questions like “what are the best materials for any application? How do they work? What are the properties of this material? Koshy explains within this school, which according to Koshy is a unique school of engineering in the faculty of science. “You have people who work on metals, ceramics, polymers, and composites”
Born in India, Koshy explained how he “always had an interest in research. I did my Bachelor’s in mechanical, but in India materials played a small component inside of the mechanical studies. Hence, I had a few courses of materials and I really liked that. That was one of my reasons why I wanted to do a masters in materials.”
Koshy then went on to study a Masters in Materials Technology. He explains: “I had an opportunity to do my thesis in the Space Center in India. We were designing a composite to be used as a material to replace metals inside a thruster for a satellite.” “We were looking at making a silicon-carbide/carbon composite which can go to high temperatures.” (the higher temperature stability would increase the performance of the thruster)
From India to Australia: A Change of Path
In 2005 Koshy moved to Australia to pursue his PhD in Material Engineering at UNSW with a full scholarship. His PhD focused on researching high temperature reactions between metals and ceramic linings to make it more resistant to reactions and improve the efficiency of melting. He explained to us with an ardent look, “If you want to melt something, how do you hold or contain it?” “You need something which goes to a higher temperature than that one to melt it. Usually metals melt at a lower temperature. So what would you use for a higher temperature?” Caroline: “Ceramics?”
Koshy: “Yes. People sometimes use sand, like the most common thing is if you want to melt something like aluminium, you can make a sand mould and then heat up, bake up the sand into something strong, and then pour the thing into it. Then the sand mould is broken off. But I was designing some high temperature materials called refractory ceramics - because they resist high temperatures. We were looking at adding some things to the ceramic to make it somewhat complex, which would prevent any reactions with the molten metal. So we found the optimal amounts that need to be added into the composition from the beginning.”
While Caroline and I were as much mesmerized and confused, which Koshy no doubt could tell, he frankly explained how “once you understand the science, then you can work on different materials.” Something which he and his big group of students understand as well.
The Future: Using Coal Ash as an alternative in Building materials and for paints.
Koshy; “I've been working with an industry partner Vecor since 2010.” Vecor is a "research and commercialization company focused on ceramics, ceramic composites and advanced materials.” At the heart of the company lies what the company has described as “utilizing materials which would otherwise become waste, and creating products which are environmentally positive, remains a central focus of the company’s R&D.” The long-term successful partnership has led to the establishment of new laboratories at UNSW in 2022 and significant industrial funding support for research and commercialisation.
One of the major waste products that is being focussed on is fly ash. Koshy explained it to us in his own words as a process. He explained how; “when you burn coal, you get something called ash leftover and it’s just stored on the site. Or sometimes companies add water and make it like a pond called an Ash pond.” What Koshy is trying to do is to use this coal ash to create value-added products for different industries.
Another product is a geopolymer containing ash that can be used as a potential substitute for cement. “In cement, you have calcium silicates, then you add water and it forms a gel which bonds everything together. But the calcium silicates to produce cement currently are manufactured using limestone and sand reactions at high temperatures. Limestone is calcium carbonate and it decomposes at high-temperatures which takes up a lot of energy and at the same time, it releases lots of carbon dioxide, so that is why the cement industry is one of the highest carbon dioxide emitting industries. So we are trying to use this coal ash and some other additives together to create aluminosilicate geopolymer gel. It is called a geo polymer because it's made of geological-based materials and polymer means a chain of repeating atoms which in this case will be aluminum, Silicon, oxygen, atoms in a gel which holds everything together..”
Fortunately, Koshy is not on his own; “I have had a lot of PhDs coming through. I also take a lot of honors students every year. Like last year I have 14 honors students and this year I have 11.” “and I supervise or co-supervise 15 higher degree research (PhD) students as well.” In addition to the work on waste material utilisation, Koshy’s group has a major focus on nanomaterials for energy and environmental applications. “I work on developing nanomaterials” he adds; “for example, a prior student and current researcher was able to develop new material types, which can easily be used to produce different shapes of nanomaterials (morphologies). And each of these shapes have different applications in different processing periods. This work has been patented again through support by Vecor with further developments expected with the continued support.”
All in the aim of making the science less robust, and more adventurous for him, the students and his fellow researchers, and for outsiders like us.
