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

A series of n -octadecane/mesoporous silica (C 18 /MS) shape-stabilized phase change materials (SSPCMs) with varying C 18 content were prepared, and the effects of adsorbed C 18 distributed within porous MS on the thermal properties were analyzed. As characterized, C 18 was first infiltrated into the mesoporous space, resulting in a SSPCM with a maximum of ∼52 wt % C 18 . Additional adsorption of C 18 occurred on the external surface of MS. Consequently, the optimum 70 wt % C 18 SSPCM had no C 18 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 % C 18 SSPCM (60.2 J/g and 68.2%, respectively). The prepared C 18 /MS SSPCMs showed excellent thermal stability and thermal reliability up to 1000 accelerated thermal cycle tests. Moreover, the C 18 /MS SSPCM incorporated in gypsum effectively reduced the temperature changes compared with the original gypsum, suggesting the promising application of the prepared C 18 /MS SSPCM for energy-saving building applications.