Preparation and properties of graphene oxide-modified poly(melamine-formaldehyde) microcapsules containing phase change material n-dodecanol for thermal energy storage
A novel kind of graphene oxide-modified poly(melamine-formaldehyde) (PMF) microcapsule containing phase change material (microPCM) n-dodecanol was prepared by in situ polymerization. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to study the chemical structure of graphene oxide (GO) and microPCMs, respectively. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to investigate the morphology of GO and microPCMs, respectively. The thermal properties of microPCMs were studied by differential scanning calorimetry (DSC), thermal constant analysis (TCA) and thermal cycling tests. The FTIR and XRD results indicate that the phase change material n-dodecanol is encapsulated in the GO/PMF composite shell, and there is no chemical reaction between them. The SEM results show that the prepared GO-modified PMF microPCMs are spherical particles with a smooth surface. The DSC results indicate that the phase change temperature and the latent heat of microPCMs with 1 wt% of GO are 26.40 °C and 125.2 J g−1, respectively. The thermal conductivity of GO/microPCMs with 4 wt% GO increases by 66.29%, compared with that of microPCMs without GO according to the TCA results. Moreover, the thermal cycling tests show that the prepared microPCMs possess a good thermal stability. The GO-modified PMF microPCMs are sure to have great potential applications in thermal energy storage.