[Osaka Institute of Technology] Development of Liquid Marbles that Efficiently Absorb CO2

A joint research group led by Professor Shuji Fujii of the Department of Applied Chemistry, Faculty of Engineering at Osaka Institute of Technology (President: Shin Inoue), who also holds an honorary professorship at Chulalongkorn University (Thailand), and Associate Professor Apichat Imyim of the Department of Chemistry, Faculty of Science at Chulalongkorn University (President: Bundhit Eua-arporn) has succeeded in developing droplets (liquid marbles) that function as carbon dioxide absorbents using naturally derived materials.

Key Points of This Research:

* Development of a new CO2 absorbent material composed of carbon particles derived from coconut shells and a liquid derived from amino acids. * The "liquid marble" structure, where liquid is encapsulated by particles, increases the CO2 absorption rate by approximately 2.5 times. * Expected to be applied to CO2 capture technologies with low environmental impact for the realization of a sustainable society.

Reducing carbon dioxide (CO2) emissions, a cause of global warming, is a worldwide challenge. Currently, various technologies are being researched to capture CO2, but many require significant energy or use artificial materials, necessitating more environmentally friendly methods.

This research group has developed a new CO2 absorbent material by encapsulating a natural liquid, "Natural Deep Eutectic Solvent (NaDES)," with "biochar particles" derived from coconut shells. By forming a "liquid marble" structure where the liquid is enclosed by particles, the internal liquid can efficiently contact the air, enhancing its gas uptake capacity. The NaDES used in this study is a highly safe liquid made from arginine, an amino acid, and glycerin, and it possesses the property of absorbing CO2. Experimental results showed that when NaDES was formed into a liquid marble structure, it absorbed CO2 approximately 2.5 times faster compared to the same amount of NaDES placed directly in a container. Furthermore, it was confirmed that the structure maintained its shape after absorbing CO2 and could be reused.

This technology is expected to be a low-environmental-impact CO2 capture technology as it utilizes only plant resources and naturally derived liquids. Additionally, because liquid marbles can move freely, they have the potential for application in gas capture in confined spaces, which has been difficult with conventional materials.

This research was supported by Grants-in-Aid for Scientific Research (B) from the Japan Society for the Promotion of Science (JSPS) (JP20H02803, JP24K01562) and the findings have been published online in the academic journal Materials Letters by Elsevier (dated May 19, 2026).

URL: https://www.sciencedirect.com/science/article/abs/pii/S0167577X26009109

DOI: 10.1016/j.matlet.2026.140950