Spin coating preparation and thermal properties of metastable Al/PVDF energetic film with graphene

Spin coating is a cost-effective technique for the preparation of thin films, widely used in the fields of physics, medicine, biology and chemistry. In this paper, we applied spin coating method to prepare metastable Al/PVDF (polyvinylidene fluoride) composite films with low mass loading of aluminum. Through controlling the speed and time of spin coating, a desired composite film can be easily obtained. In order to adjust the performance of the films, coupling agent γ-methacryloxypropyl trimethoxy silane (KH-570) and graphene were added. Morphology, structure and thermal analysis were carried out by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), x-ray diffractometer (XRD) and thermogravimetry-differential scanning calorimetry (TG-DSC). The results indicate that the appropriate amount of KH-570 not only improve the dispersibility of Al in the film significantly, but also advance the temperature of the reaction between Al₂O₃ shell and fluorine from 372 °C to 350 °C. While graphene delay the progress of the reaction between Al₂O₃ shell and fluorine from 350 °C to 370 °C, and change the reaction exotherm mode (the exothermic peak changes from three to four). Kinetic analysis of exothermic peaks indicates that the apparent activation energy calculated by Kissinger method is slightly lowered after the addition of graphene. After adding graphene, the apparent activation energy corresponding to each exothermic peak changes from 244.47 kJ mol^-1, 175.03 kJ mol^-1, 245.90 kJ mol^-1 to 213.80 kJ mol^-1, 131.80 kJ mol^-1, 218.50 kJ mol^-1 (and 172.10 kJ mol^-1).