Fluorinated Viologen Electrochromic Polymers for Fault Indication of Power Equipment

With the promotion of UHV transmission, power equipment operates at high voltage for long durations, which increases the risk of insulation failure. This may cause electricity leakage or other fault conditions of power equipment, which pose threat to the safety of maintenance operators. However, the traditional electroscope facility is large, while the electricity verification process is complicated. In order to overcome such problem, electrochromism is used to realize the visual self-sensing of fault conditions of power equipment. Viologen is a type of classic electrochromic small molecules. In the REDOX process of viologen, the formation of dimer reduces the cyclic stability of electrochromism significantly, which is not conducive to engineering practice. In this case, a fluorinated viologen with -(CH₂)₂-C₂F₅ side group was synthesized. The strong electron absorption properties of fluorinated groups improved the color rendering contrast. The UV-visible absorption spectrum showed that with the introduction of fluorine atoms, the absorption of viologen increased at 390 nm and 600 nm. The repulsive effect of fluorinated groups introduced by its high electron density avoids the agglomeration of viologen, leading to highly overlapped cyclic voltammetry curves, indicates good cyclic stability for long-duration applications. Such synthesized fluorinated viologen is expected to improve the naked-eye observation ability and long-term stability of electrochromic devices, which promote the application possibility of such materials in visual indication of fault conditions of power equipment.