Yuan Chengyang, Zong Hongxiang, Dong Hongsheng, Yang Lei, Gao Yufei, Fan Zhen, Zhang Lunxiang, Zhao Jiafei, Song Yongchen, Tse John S
Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian, China.
Department of Chemistry and Bioscience, Aalborg University, Aalborg East, Denmark.
Nat Commun. 2024 Nov 2;15(1):9477. doi: 10.1038/s41467-024-53698-0.
Materials with low lattice thermal conductivity are essential for various heat-related applications like thermoelectrics, and usual approaches for achieving this rely on specific crystalline structures. Here, we report a strategy for thermal conductivity reduction and regulation via guest rotational dynamics and their couplings with lattice vibrations. By applying pressure to manipulate rotational states, we find the intensified rotor-lattice couplings of compressed methane hydrate MH-III can trigger strong phonon scatterings and phonon localizations, enabling an almost three-fold suppression of thermal conductivity. Besides, the disorder in methane rotational dynamics results in anharmonic interactions and nonlinear pressure-dependent heat transport. The overall guest rotational dynamics and heat conduction changes can be flexibly regulated by the rotor-lattice coupling strength. We further underscore that this reduction mechanism can be extended to a wide range of systems with different structures. The results demonstrate a potentially universal method for reducing or controlling heat transport by developing a hybrid system with tailored molecular rotors.
具有低晶格热导率的材料对于热电等各种与热相关的应用至关重要，而实现这一目标的常用方法依赖于特定的晶体结构。在此，我们报告一种通过客体旋转动力学及其与晶格振动的耦合来降低和调节热导率的策略。通过施加压力来操纵旋转状态，我们发现压缩甲烷水合物MH-III增强的转子-晶格耦合能够引发强烈的声子散射和声子局域化，从而使热导率几乎降低三倍。此外，甲烷旋转动力学中的无序导致非谐相互作用和与压力相关的非线性热输运。客体的整体旋转动力学和热传导变化可通过转子-晶格耦合强度灵活调节。我们进一步强调，这种降低机制可扩展到具有不同结构的广泛系统。结果表明，通过开发具有定制分子转子的混合系统，可能存在一种通用方法来降低或控制热输运。
