| Abstract: | Microencapsulated n-alkanes as energy-storage materials have promising application prospects.The microcapsules containing 100-50 wt% of n-octadecane,0-20 wt% of paraffin and 0-30 wt% of cyciohexane were synthesized by in-situ polymerization using melamineformaldehyde polymer as shell.Cyclohexane was removed after heat-treated the microcapsules at 100℃.The morphologies,cell parameters,phase change properties,thermal stable temperatures of these micrecapsules were examined.The diameters of these mieroeapsules arc lower than 5 μm.The effect of paraffin in the microcapsules on the cell parameters of,n-octadecane is negligible.The paraffin is effectively used as a nucleating agent to decrease the degree of supercooling.The melting enthalpy is decreased from 132 J/g to 111 J/g due to the increase of the cyciohexane contents.The thermal stable temperature is enhanced 6-16℃ after heat-treated the microcales at 160℃ for 30 min. |
