Illustration of the of the structure of a metal-organic framework

Hong Kong researchers unlock key to boosting eco-friendly cooling

3 June 2024

In an important new study published in Nature Communications, researchers from the Hong Kong University of Science and Technology (HKUST) have unveiled a new strategy to enhance the performance of sustainable cooling systems. Led by Dr Yanguang Zhou from the Department of Mechanical and Aerospace Engineering, the team has discovered a way to significantly improve heat transfer in metal-organic frameworks (MOFs), a promising material for passive cooling applications.

MOFs are versatile, porous materials known for their ability to capture water vapour, making them ideal candidates for cooling electronics, buildings, and solar panels. However, their low thermal conductivity has been a limiting factor in their widespread adoption. The HKUST researchers tackled this challenge by focusing on the interfacial heat dissipation between MOFs and the surfaces they are in contact with.

Through their innovative approach, the team demonstrated that the interfacial thermal conductance between MOFs and substrates can be increased by up to 7.1 times. This remarkable enhancement is achieved by the formation of dense water channels within the MOFs, which act as additional thermal pathways, facilitating efficient heat transfer.

The researchers discovered that the adsorbed water molecules not only activate high-frequency vibrations but also increase the overlap of vibrational density of states between the substrate and MOF creating a “bridge effect” that enables efficient thermal energy dissipation.

This development creates new possibilities for the development of more effective and sustainable cooling technologies, addressing the growing demand for energy-efficient solutions in our warming world.