Natural Microtubule-Encapsulated Phase-Change Material with Simultaneously High Latent Heat Capacity and Enhanced Thermal Conductivity

It is of critical importance to exploit high-performance phase-change materials (PCM) for thermal energy storage. Present form-stable PCM suffer from the defects in low PCM loading, poor form stability, low thermal conductivity, and complicated approaches. We prepared a novel microtubule-encapsulated phase-change material (MTPCM) by encapsulating lauric acid (LA) into kapok fiber (KF) microtubules that had been precoated with silver nanoparticles. The measured melting and freezing temperatures were 43.9 and 41.3 °C for the LA/KF MTPCM and 44.1 and 42.1 °C for the LA/KF@Ag MTPCM, respectively. After being heated, the MTPCM can retain its original solid state without leaking, even under a pressure of 500 times the gravity of MTPCM itself, which shows that the encapsulated phase-change material can undergo a solid–liquid transition microscopically while retaining its macroscopic solid state. The latent heats of fusion were found to be 153.5 J/g for the LA/KF MTPCM and 146.8 J/g for the LA/KF@Ag MTPCM, which ...