Synthesis Of Viologen Compounds And Their Electrochromism In Eutectic Solvents

Electrochromic materials are a new type of smart materials that can be widely used in various fields,such as display,smart windows,and storage of information.Due to its excellent electrochemical properties and controllable multicolor,viologen and its derivates are widely used as the electrochromic materials.In this thesis,three kinds of viologens(butyl viologen,cyanophenyl viologen,mono-substituted benzyl viologen)were synthesized.With the eutectic solvent choline chloride-ethylene glycol(1:2.5)used as the electrolyte,hydroxy-ferrocene used electron donor,the thin-layer liquid electrochromic devices were assembled.The devices are transparent in their bleached states and shows blue,green and red in their colored states,respectively.By adding 10% wt nano-Si O2-380,the eutectic solvent could be gelated.The obtained semisolid thin layer electrochromic devices the solid thin layer electrochromic device showed better cycle stability than the liquid electrochromic device,with the electrochromic effects from transparent to blue,green and purple.This thesis also studied the feasibility of using ferrous chloride as an electron donor.Results showed that ferrous chloride has excellent stability in choline chloride-ethylene glycol eutectic solvent.In the application of electrochromic devices,it is necessary to plate graphene oxide to exhibit good redox reversibility.Compared with hydroxyferrocene as an electron donor,the most suitable color change voltage of the device is reduced by 0.1V.