Preparation of porous carbonized woods impregnated with lauric acid as shape-stable composite phase change materials

Abstract

Porous carbonized woods (PCWs) were prepared by delignification and carbonization treatment of sycamore woods as encapsulation materials of lauric acid (LA) phase change materials (PCMs). The PCWs exhibited regular oriented pore structure (10–20 μm), high porosity (88.86%), low bulk density (0.15 g/cm3), and large pore volume (5.80 cm3/g), which allowed larger heat storage capacity of LA and lightweight characteristic. LA/PCWs shape-stable composite phase change materials (LA/PCWs ss-CPCMs) showed maximum adsorption ratio of LA (81.1 wt.%). The DSC results indicated that the phase change temperatures and latent heat of LA/PCWs ss-CPCMs were respectively 41.0 °C and 177.9 J/g in melting process, and 38.9 °C and 178.2 J/g in solidification process, respectively. PCWs showed little restrictive effect on the phase change behavior of LA. Non-isothermal crystallization results showed that the activation energy of LA (−333.4 kJ/mol) was higher than that of LA/PDCWs (−170.47 kJ/mol) but the half crystallization time of LA was lower than that of LA/PDCWs, indicating that PCWs significantly increased the nucleation rate of LA but slightly limited its crystal growth. Thermal cycles test, FT-IR and TGA results indicated that the LA/PCWs ss-CPCMs showed excellent thermal reliability, chemical compatibility and thermal stability.