| 초록 |
Recently, study of phase change materials (PCMs) has been attracted in the research of latent heat storage due to their high latent heat of transition, high energy density and low cost. Encapsulated PCMs show many advantages, such as increasing heat transfer area, reducing PCMs reactivity towards the outside environment and controlling the changes in the storage material volume as phase change occurs. In this study, sub micro-encapsulated paraffin wax was prepared by emulsion polymerization. Melamine and formaldehyde were used as shell materials, and citric acid was used as pH adjustment agent. Capsule size was measured by scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and statistical analysis of prepared capsules was performed by image process. The capsule size and dispersibility were affected by adding rate of citric acid. Capsule size distribution of encapsulated wax was about 250 to 400 nm, and from the DSC, their ΔH was 75 J/g. |
