Solid-solid phase transition of (1-C14H29NH3)2ZnCl4 in nanopores of silica gel for thermal energy storage

Latent heat storage performance of a layered perovskite-type compound, 1-C 14 H 29 NH 3 ) 2 ZnCl 4 (C 14 Zn), embedded in a series of silica gel (SG) with pore sizes of d   =   15–200   nm is investigated using differential scanning calorimetry (DSC), and powder X-ray diffractions (XRD). C 14 Zn in the nanopores of silica gel shows size-dependent phase transition temperature, enthalpy change and supercooling. They have a stable transition temperature and heat capacity at each size in a short-term thermal cycling. Similar X-ray diffraction patterns are observed for the nano-sized and the bulk C 14 Zn. The encapsulation of a phase change material in nanopores is a new way of tuning its thermal energy storage properties for a wider range of temperature regulation.