‘Clay: From pottery to supercapacitors and plasticine sculptures to LDH solar panels’—inaugural address of Prof Johan Labuschagné

14 March 2022 was a milestone day for Prof Johan Labuschagné, a professor in the Department of Chemical Engineering, Institute of Applied Materials, as he delivered his inaugural lecture virtually, titled ‘Clay: From pottery to supercapacitors and plasticine sculptures to LDH solar panels’. The Acting Dean of the Faculty of Engineering, Built Environment and Information Technology (EBIT), Prof Jan Eloff, welcomed the guests and invited the Acting Vice-Principal: Research, Innovation and Postgraduate Education to introduce Prof Johan Labuschagné.

Prof Labuschagné obtained his bachelor’s degree in chemical engineering in 1998 from the University of Pretoria. He started research in the polymer field during his postgraduate studies under Prof Walter Focke in the field of organo-metallic-based intumescent flame retardants. On completing his PhD in 2003 at the University of Pretoria, South Africa, he left academia to do industrial research, leading a project funded jointly by industry and the South African government. Together with his team, Prof Labuschagné developed and patented a novel process to beneficiate mined raw materials into high-value polymer additives such as synthetic hydrotalcite—an anionic clay. Funding has been obtained to erect a full-scale commercial plant in collaboration with the CSIR. During his time in industry, Prof Labuschagné kept in close contact with Prof Focke, supplying him with hydrotalcite samples for modification and intercalation studies, as well as evaluation of their use in other polymers and applications. In 2009, Prof Labuschagné re-joined the University of Pretoria to work on hydrotalcite-related research. He is currently focusing on broadening the patented process to include other layered double hydroxide (LDH) materials, LDH modification and new applications. In addition to research work, Prof Labuschagné currently lectures three undergraduate courses and one postgraduate course in chemical engineering at the University of Pretoria. His other academic accomplishments include the publication of 35 peer-reviewed articles in accredited journals, three South African patents, three provisional patents and several national and international conference presentations. Prof Labuschagné has also supervised seven PhD and 21 master’s students.

Prof Labuschagné took us on a journey of his research, highlighting the patented zero-effluent, environmentally friendly synthesis of LDHs and its application in polymers, renewable fuels and energy.

According to Prof Labuschagné, clay is the oldest known ceramic material, with pottery shards dating back as far as 14 000 BC having been discovered. Applications of clay include pottery, art, earth dam linings, cement, bricks, water softeners, paper, lubricants, chemical filters, medicine and many more. Prof Labuschagné added that there are many different types of ‘pure’, naturally occurring clay minerals that are layered in structure. These layers typically carry an electrical charge, balanced by counterions. He added that anionic clays make up a small fraction of naturally occurring clay and comprise positively charged layers with anionic (negatively charged) counterions. The most well-known naturally occurring anionic clay mineral is hydrotalcite, an LDH of magnesium and aluminium that typically has carbonate as a counteranion in between the layers. Prof Labuschagné added that although hydrotalcite was first discovered in 1842 in small, impure, non-commercial deposits, the first synthesis of a synthetic hydrotalcite was described in 1942. Large-scale commercial production commenced in the 1970s due to the use of hydrotalcite for medicinal purposes (antacid) and its potential as a catalyst. In 2021, a total of 2 251 journal articles were published with ‘hydrotalcite’ or ‘layered double hydroxide’ in the title, keywords or abstract, and more than 21 000 journal articles including these terms have been published since 1942 (Scopus database). Prof Labuschagné’s most recent research has shown the potential use of LDH in solar panels and supercapacitors and as a photocatalyst. With innovation and sustainability at the forefront of our daily lives, the vast potential application of LDHs is both inspiring and exciting.

Prof Jan Eloff, the Acting Dean of EBIT, thanked Prof Labuschagné for his very informative lecture. Prof Eloff highlighted Prof Labuschagné’s reference to the importance of patents and their commercialisation. Such research not only introduces a zero-effluent, environmentally friendly process, leveraging principles of green chemistry, but also helps build the economy of our country. Prof Eloff added that it was clear that Prof Labuschagné’s lecture and research focus were on sustainability. He commended Prof Labuschagné for his contribution to renewable, sustainable energy generation and storage and energy at large.

Congratulations, Prof Labuschagné. We look forward to more ground-breaking research towards a sustainable future.

For Prof Labuschagné’s full inaugural address, please visit this link.