Lauric acid/MIL-101-NH2 composite enhanced thermal conductivity and thermal stability of phase change material for thermal energy management: Experiment and molecular dynamics simulations

Developing phase change materials (PCMs) with high energy storage efficiency, thermal conductivity, and shape stability is important for thermal management of electronic devices and other low-temperature energy-storage applications. In this study, amino-functionalized MIL-101 (MIL-101-NH₂) was used as a porous metal-organic framework carrier, and lauric acid (LA) was used as the organic PCM. LA was incorporated into MIL-101 and MIL-101-NH₂ through solution impregnation to construct shape-stable composite phase change materials (CPCMs). The optimized LA/MIL-101-NH₂-3 sample exhibited a thermal conductivity of 0.818 W/m·K, which is 337% higher than that of pure LA (0.187 W/m·K), while maintaining a melting enthalpy of 69.4 J/g. Molecular dynamics (MD) simulations further revealed that amino groups on the MIL-101-NH₂ framework form abundant hydrogen bonds with the carboxyl groups of LA, strengthen interfacial phonon coupling, and reduce interfacial thermal resistance. Post-impregnation pore analysis, leakage tests, thermal cycling, and thermal management experiments jointly confirm that the improved performance originates from the synergistic effects of pore confinement, amino-mediated interfacial interactions, and continuous MOF-assisted heat-transfer pathways. This work provides experimental evidence and molecular-level insight for the rational design of MOF-based CPCMs for thermal energy management and broader low-temperature latent heat storage applications.