| 초록 |
A new and effective approach has been proposed for determining the thickness of a non-freezable layer (Tnl) of n-octadecane in mesoporous silica materials. Three ordered mesoporous silica—MCM-41, SBA-15, and large pore SBA-15 (LSBA-15) were prepared and impregnated with at least three different ratios of n-octadecane. Low heat recovery was obtained (14.3%–82.1%) because of the non-freezable layer. The percentages of the non-freezable layer were reliably calculated from linear regressions with the latent heat density as a function of PCM loading. Tnl was then determined through a quadratic equation and found to be almost the same for both compounds, 0.55 nm and 0.53 nm for SBA-15 and LSBA-15, respectively. The reliability and applicability of the new approach were investigated for disordered silica through the prediction of latent heat density. Good compatibility was achieved with errors of 0–8.9% between the predicted and experimental values. |
