Supercooling Suppression of Microencapsulated n-Alkanes by Introducing an Organic Gelator

• 出 处: Chemical Research in Chinese Universities
• 发表日期: 2012年03期
• 关键词: alkanes polymerization spherical enthalpy Suppression suppressed melting suppres

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,melamine-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 gelator 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 remarkable suppression ability of the organic gelator on supercooling.

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, melamine-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 gelator into the core of microcapsules to cope with the supercooling problem. Analysis demonstrated 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 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 pure of n-alkanes, suggesting the rem arkable suppression ability of the organic gelator on supercooling.