Researchers B. I. Min and J.-S. Kang from the Department of Physics at Pohang University of Science and Technology in South Korea have published a study in the Journal of Physical Chemistry Letters that sheds light on the unique thermal properties of water and ice, with potential implications for the energy industry.
Water and ice exhibit unusual thermal behaviors, such as negative thermal expansion (NTE) and abnormal volume isotope effects (VIE). NTE refers to the phenomenon where a substance contracts when heated, rather than expanding, while VIE occurs when replacing hydrogen (H) with its heavier isotope, deuterium (D), causing a volume expansion. These phenomena have been observed in ice at low temperatures and in water near freezing point.
The researchers employed a Born-Oppenheimer-approximation approach and the Lindemann criterion to investigate isotope effects on NTE and melting properties in ice and water. Their findings reveal that these unusual isotope effects arise from the competition between zero-point-energy phonons, thermal phonons, and hydrogen bonding in water. Phonons are collective excitations of atoms or molecules in a lattice, and zero-point energy refers to the lowest possible energy state of a quantum mechanical system.
The study highlights the crucial role of quantum mechanical (QM) processes in the seemingly classical systems of ice and water. Understanding these phenomena can have practical applications in the energy industry, particularly in areas such as desalination, ice storage for cooling systems, and the development of advanced materials for energy storage and conversion. For instance, the unique thermal properties of water and ice could be harnessed to improve the efficiency of thermal energy storage systems, which are essential for renewable energy integration and grid stability.
By elucidating the underlying mechanisms of NTE and VIE, this research contributes to a more comprehensive understanding of water’s thermal properties, potentially paving the way for innovative solutions in the energy sector. The study was published in the Journal of Physical Chemistry Letters, a peer-reviewed scientific journal covering research in physical chemistry, nanotechnology, and materials science.
This article is based on research available at arXiv.