Supercooling Suppression of Microencapsulated n-Alkanes by Introducing an Organic Gelator
摘要
Supercooling of the microencapsulated phase change materials(PCMs) during cooling usually happens. This phenomenon can interfere with heat transfer and is necessary to further overcome. In this study, mela- mine-formaldehyde microcapsules containing two n-alkane PCMs, namely, n-dodecane(C12) or n-tetradecane(C14) were prepared by in situ polymerization. A small amount of n-hexatriacontane(C36) was introduced as an organic ge- lator into the core of microcapsules to cope with the supercooling problem. Analyses demonstrate that supercooling of the microencapsulated C12 or C14 was significantly suppressed by adding 3%(mass fraction) C36, without changing the spherical morphology and dispersibility. It could be also found that the enthalpy of microencapsulated C12 or C14 containing C36 was similar to that of microencapsulated n-alkanes without C36, whereas the difference between onsets of crystallization and melting(degree of supercooling) is similar to that of those of pure n-alkanes, suggesting the re- markable suppression ability of the organic gelator on supercooling. Keywords Supercooling; Microcapsule; Phase change material; Gelator; n-Alkane Article ID 1005-9040(2012)-03-539-03