Synthesis and characterization of Capric acid-Lauric acid/expanded vermiculite as a phase change composite for thermal energy storage

Abstract

In this study, a new kind of composite phase change material (PCM) using expanded vermiculite (EVM) as the matrix and Capric acid-Lauric acid (CA-LA) binary eutectic as the adsorbent was fabricated by vacuum impregnation technology. The devised composite CA-LA/EVM with 60 % loadage of CA-LA and melts at 18.42 °C with a latent heat of 66.08 J/g. In addition, in order to investigate whether the prepared composite CA-LA/EVM can be used in building envelope for energy conservation, we mixed it as heat regulating medium to prepare the phase change concrete, the mechanical, thermal performance, failure patterns and stress concentration of CA-LA/EVM-based phase change concrete was studied systematically. The results indicate that incorporating CA-LA/EVM into concrete can observably enhance the specific heat capacity and heat storage capacity of concrete. It is important to emphasize that the failure cracks in CA-LA/EVM-based concrete mainly extend along the interface between CA-LA/EVM and cement slurry, the effect of axial strain on the strength of CA-LA/EVM-based phase change concrete has been noted to be particularly significant.