Enhanced Thermal Energy Storage of n-Octadecane-Impregnated Mesoporous Silica as a Novel Shape-Stabilized Phase Change Material.

Abstract

A series of n-octadecane/mesoporous silica (C18/MS) shape-stabilized phase change materials (SSPCMs) with varying C18 content were prepared, and the effects of adsorbed C18 distributed within porous MS on the thermal properties were analyzed. As characterized, C18 was first infiltrated into the mesoporous space, resulting in a SSPCM with a maximum of ∼52 wt % C18. Additional adsorption of C18 occurred on the external surface of MS. Consequently, the optimum 70 wt % C18 SSPCM had no C18 leakage and exhibited a heat storage capacity of 135.6 J/g and crystallinity of 83.5%, which were much larger than those of 52 wt % C18 SSPCM (60.2 J/g and 68.2%, respectively). The prepared C18/MS SSPCMs showed excellent thermal stability and thermal reliability up to 1000 accelerated thermal cycle tests. Moreover, the C18/MS SSPCM incorporated in gypsum effectively reduced the temperature changes compared with the original gypsum, suggesting the promising application of the prepared C18/MS SSPCM for energy-saving building applications.