Intriguing triboelectrification behavior of identical P(VDF-TrFE) polymers

We report an intriguing triboelectrification behavior of thermally treated P(VDF-TrFE) polymers. Cooled (C-) and annealed (A-) P(VDF-TrFE) films were prepared by the rapid cooling of the melt solution and the subsequent annealing, respectively. The C–P(VDF-TrFE) had sparse grains and small elastic modulus and surface charge density, while, the A-P(VDF-TrFE) had dense grains and large elastic modulus and surface charge density. When the polymers contacted ITO electrodes, the triboelectric outputs of C-(PVDF-TrFE) were larger than those of A-P(VDF-TrFE). When the polymers contacted each other, the triboelectric outputs of different P(VDF-TrFE) films were significantly larger than those of similar P(VDF-TrFE) films. Based on detailed X-ray photoemission spectroscopy results, we suggested that roughness-induced frictional heat and elastic modulus differences may play an important role in minute material and/or ion transfer during the triboelectrification of identical P(VDF-TrFE) polymers.