Chen Haonan, Saren Sagar, Liu Xuetao, Jeong Ji Hwan, Miyazaki Takahiko, Kim Young-Deuk, Thu Kyaw
Department of Advanced Environmental Science and Engineering, Faculty of Engineering Sciences, Kyushu University, Kasuga-koen 6-1, Kasuga, Fukuoka 816-8580, Japan.
Institute of Innovation for Future Society, Nagoya University, Furu-cho, Chikusa, Nagoya, Aichi 464-8603, Japan.
iScience. 2024 Jul 4;27(8):110449. doi: 10.1016/j.isci.2024.110449. eCollection 2024 Aug 16.
Understanding changes in thermodynamic and transport properties during adsorption is crucial for the thermal management of metal-organic frameworks, which also imposes significant challenges for improved performance and energy density of adsorption system. Because of phase transitions in the intermolecular interactions involved in the adsorption phenomena, transport properties including the thermal conductivity exhibit interesting behaviors, yet fully understood. This study employs detailed molecular dynamics simulations to replicate the methane/Cu-BTC adsorption phenomenon for the evaluation of their thermal conductivities across different pressures and temperatures. The molecular simulations show that the thermal conductivities of both the adsorbent (Cu-BTC) and adsorbate (methane, adsorbed phase) vary notably during adsorption processes. Using the concepts of the change in the degree of free movements of the adsorbate molecules and atomic vibration of adsorbent, the reduction of the adsorbate thermal conductivity (∼70-93%) and increase thermal conductivity of the adsorbent (up to 3 times) in Cu-BTC+CH pair are explained.
了解吸附过程中热力学和传输性质的变化对于金属有机框架的热管理至关重要，这也对提高吸附系统的性能和能量密度提出了重大挑战。由于吸附现象中涉及的分子间相互作用发生相变，包括热导率在内的传输性质表现出有趣的行为，但尚未完全理解。本研究采用详细的分子动力学模拟来复制甲烷/Cu-BTC吸附现象，以评估其在不同压力和温度下的热导率。分子模拟表明，吸附剂（Cu-BTC）和吸附质（甲烷，吸附相）的热导率在吸附过程中均有显著变化。利用吸附质分子自由移动程度变化和吸附剂原子振动的概念，解释了Cu-BTC+CH对中吸附质热导率的降低（约70-93%）和吸附剂热导率的增加（高达3倍）。
