American researchers from the University of Princeton working in aerospace technology have produced from egg protein a lightweight, highly porous aerogel, that is said to be suitable for removing microplastic from seawater. For this, the protein is freeze-dried and heated in an environment without oxygen to 900 °C until the desired aerogel structure is formed. According to the scientists, the resulting material removes microplastic from the water with an efficiency of more than 99 percent.
 

A research team from the Princeton Engineering section, headed by Craig Arnold, Professor of Mechanical and Aerospace Engineering and Vice Dean of Innovation in Princeton, works on the development of new materials, including aerogels for technical applications. Aerogels are highly porous solids with a volume consisting of up to 99.9 percent of pores. According to a research report published in the journal Materials Today, Arnold and his colleagues showed that an aerogel obtained from egg protein can remove microplastic from seawater with an efficiency of up to 99.9 percent. To produce the protein-based aerogel, the egg protein was first deep-dried and subsequently heated in an oxygen-free environment to 900 °C. This results in the formation of a structure of very low density consisting of interconnected carbon fibre strands and graphene layers. The research team then used the aerogel for desalination and cleaning the water and found that, in this way, 99.9 percent of the microplastic was removed from the water. The cleaning of the water with the aerogel even functioned if the egg protein was first cooked or beaten, explained materials scientist and co-author of the study, Sehmus Ozden. Other proteins could also be used to produce aerogels, which means that the material could potentially be produced in large quantities relatively cheaply, said Ozden. In the next step, the production process will be refined in order to be able to use the material on a larger scale for cleaning water.

 

Sources:

• „Egg protein derived ultralightweight hybrid monolithic aerogel for water purification“, Sehmus Ozden, Susanna Monti, Valentina Tozzini, Nikita S.Dutta, Stefania Gili, Nick Caggiano, James Link, Nicola M. Pugno, John Higgins, Rodney D. Priestley, Craig B. Arnold, Materials Today, Volume 59, October 2022
• chemie.de (Nov. 16, 2022)
• engineering.princeton.edu (Nov. 3, 2022)
• Photo: © Shaharyar Wani