Porous organic–inorganic hybrid xerogels for stearic acid shape-stabilized phase change materials

Abstract

An organic–inorganic hybrid porous metal–organic gel (MOG) based on Cr³⁺ and bridging benzene-1,3,5-tricarboxylic acid (BTC) was synthesized. The MOG exhibited good porosity, flexibility and a high surface area to encapsulate stearic acid (SA) for phase change materials (PCMs). The porosity of MOG-100 (Cr) guaranteed an excellent thermal stability of the encapsulated stearic acid. No leakage of PCMs was observed from the MOG even after heating the SA@MOG-100 (Cr) composites beyond their melting point. A maximum weight percentage as high as 90% of stearic acid has been achieved without leakage. The melting temperature of the SA@MOG-100 (Cr) composite was 71.9 °C and the total latent heat of fusion of the composite was measured to be in the range of 101–189.3 kJ kg⁻¹. They present excellent thermal recyclability within at least 15 melting/freezing cycles.