Research on Adjusting the Thermal and Cycle Stability of Phase Change Microcapsules by Polydopamine Shell Mass.

The wide application of phase change microcapsules (MicroPCMs) is constrained by their leakage and low stability. In this study, the shell material of microcapsules is optimized to achieve superior thermal stability and anti-leakage. N-Octadecane (n-OD) is utilized as the phase change material (PCM), and a dual-shell architecture consisting of silicon dioxide (SiO 2) and polydopamine (PDA) is constructed. The influence of the added dopamine (DA) on the thermal performance of the microcapsules is investigated by the self-polymerization property of DA. The results indicate that no significant decrease in the heat storage capacity of the PDA-modified microcapsules even if the mass fraction of DA reaches 30%. Moreover, compared to that of the single-shell sample, the microcapsules with a PDA-coated shell exhibit better thermal stability, cycle durability and anti-leakage. The presence of an appropriate PDA layer can effectively depress leakage, and enhance interfacial stability and thermal cycling performance. Owing to its distinctive multilayer shell architecture, the resulting specimens exhibit better durability. A dual-layer shell structure on the phase change material (PCM) surface was created by applying PDA self-polymerization to modify silica (SiO2) for stability enhancement. When the DA content reaches 3/10 of the mass of the n-OD-based microcapsule, the PDA outer shell greatly enhances the thermal and cyclic stability of the modified microcapsules, while effectively inhibiting molten n-OD leakage. [ABSTRACT FROM AUTHOR]