Paola Fusi interviews Gian Domenico Sorarù
Scientific research in the area of nanomaterials is progressing in leaps and bounds. Here we tell you about a new patent application by a group of researchers in the Glass and Ceramics Laboratory of the Department of Industrial Engineering of the University of Trento, led by Professor Gian Domenico Sorarù, professor of materials science and technology and materials for energy. The patent was developed by Professor Sorarù and the researchers Emanuele Zera and Prasanta Jana. The patent application, owned by the University of Trento, was filed in Italy in November last year and we are working on extending it to the European level. The invention is a high-tech felt, with one of the highest levels of thermal insulation ever measured: a material that will have a wide range of applications both in the textile industry and in construction. To learn more about it, we met Professor Gian Domenico Sorarù, who explained what this material is and what potential it has.
Professor Sorarù, what are the characteristics of the material that you have developed, and what does it offer compared to materials that are currently available?
The material that we have developed is a felt that consists of nano-filaments based on silicon nitride, a ceramic material with exceptional properties of both chemical and thermal resistance. The fibres are just a few nanometres thick, so around 1000 times thinner than a human hair, and are tens of microns in length. The most important characteristic of this material is that it has a level of thermal insulation similar to the most insulating material yet known, silica aerogel. The advantage of our patent over aerogel is that the felt can be produced very quickly and with much simpler machinery and therefore lower costs.
What applications will this new material have?
This “high tech” felt could be used in construction or in industry to reduce heat loss in buildings or equipment. Its flexibility means that it could also have applications in the textile industry to produce jackets and other clothes for very cold weather. Given that it also has a very high porosity (1 cm3 of material is 92% air and only 8% solid material) and chemical stability, it could also be used for the filtration of liquids or gases.
How did you come up with this material?
For some time, our research group in the Glass and Ceramics Laboratory in the Department of Industrial Engineering has been studying the production of ceramics from polymeric precursors. In this study we realized that when the classic flexible polyurethanes that are used in packaging and for sofas and armchairs were impregnated with silicon and heated in a furnace to high temperature in the presence of nitrogen gas, they were converted into silicon nitride nanofelt. It was, in a sense, a chance discovery, as often happens in science. A lot of work and a lot of tests then followed, to understand and control the chemical reactions involved in the process.
Your research is now a new patent application. What steps do you plan to take to bring it to market and when might it begin to be used in industry?
At the moment this product is only available at the laboratory scale (we produce square samples of a few centimetres each side and a few millimetres in thickness), so to manufacture it a lot of experimental work is still necessary to optimize the variables in the process, to scale it up and to produce larger samples. Our laboratory does not have the equipment for these activities. We will need to buy larger furnaces and equipment for measuring thermal conductivity, as well as needing one or two researchers dedicated to this project. So at the moment we are on standby, waiting until the conditions are right to continue the research. We are also looking for partners interested in collaborating with us: companies interested in materials innovation, whether in the textile sector, the building materials sector, or in advanced materials in general.
I invite such companies to come and meet us and look together at whether we can set up a collaboration agreement to help bring this patent to market.
I would also add that the unique characteristics of this material, which make it highly competitive in both performance and cost, could make it a good basis for a startup.