Preparation and characterization of magnetic phase-change microcapsules

Magnetic microcapsules containing paraffin cores within urea-formaldehyde shells were fabricated utilizing in situ polymerization, with iron nano-particles as magnetic particles. The thermal properties, surface morphologies, magnetic properties and iron nano-particles content of the magnetic phasechange microcapsules were investigated by scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), vibrating sample magnetometry (VSM) and inductively coupled plasma quantometry (ICP). The influence of iron nano-particles on morphologies was also considered. The results indicate that the melting point of magnetic phase-change microcapsules is almost identical to that of paraffin. The magnetism parameters such as specific saturation magnetization and residual magnetization of magnetic phase-change microcapsules increase with the increase of iron nano-particles content. Supported by National Natural Science Foundation of China (Grant No. 50436020)