Understanding molecular motion mechanism of phase change materials in mesoporous MCM-41.

Although nanoporous shape-stabilized composite phase change materials (PCMs) could efficiently address the leakage issue of pure PCMs during the solid-liquid phase transition process, numerous experiments have verified that the thermophysical parameters of the nanoporous shape-stabilized composite PCMs are significantly different from those of macroscopic bulk PCMs due to the nanoconfinement effects. However, macroscopic experimental data cannot directly reflect the microscopic interaction mechanisms in composite PCMs. Herein, to systematically understand the molecular motion mechanisms of PCMs with different functional groups (octadecane, octadecylamine, octadecanol and stearic acid) confined in the mesoporous MCM-41, we utilize molecular dynamics to simulate the spatial distribution and motion states of surface adsorbed PCMs molecules. This study aims to systematically reveal the interaction mechanisms between mesoporous MCM-41 and surface adsorbed PCMs at the molecular and atomic levels, thus providing constructive theoretical guidance and reference data for the targeted design and preparation of high-performance MCM-41-based composite PCMs. Image 1 • Molecular dynamics method is utilized to study thermal motion states of PCMs in mesoporous MCM-41. • The interaction mechanisms between MCM-41 and PCMs are systematically revealed at the molecular level. • It provides constructive guidance for the preparation of MCM-41-based composite PCMs. [ABSTRACT FROM AUTHOR]