Study On The Preparation And Properties Of Polyaniline Modified Electrode For IR-electrochromic Device

Aiming at the requirements of the reflective mode IR-electrochromic device and considering the dynamic changes in IR region of polyaniline, this work focuses on preparing the polyaniline-modified electrodes which can be used as the top electrode and the bottom electrode of the IR-electrochromic device. Au/PET was used as the substrate of the bottom electrode, and Au/PES was used as the substrate of the top electrode. The top electrode (PAn/Au/PET) and the bottom electrode (PAn/Au/PES) were both obtained in the sulfuric solution using galvanostatic method. The interrelation between the electrochemical preparation of polyaniline-modified electrodes and conditions in the electropolymerization process, such as current density, polymerization time, monomer concentration and sulfuric acid concentration, had been analyzed. The electrochemical conditions which can be used toprepare PAn/Au/PET and PAn/Au/PES were confirmed. The prototypal IR-electrochromic devices were fabricated with the top electrodes and the bottom electrodes we prepared. It's properties, such as electrochromic , IR-electrochromic, switching time and cyclability, were investigated.It was showed that, to prepare the bottom electrodes with the good cycle reversibility, the ideal electrochemical condition was 1:0.7H₂SO₄:C_An≤1:0.5 (C_H2SO4=1mol/L),1:0.5≤C_H2SO4:C_An≤2:0.5(C_An=0.5mol/L),0.05mA/cm²≤i<0.1mA/cm²,t≥60min.In order to obtain the top electrodes with the continuous polyaniline film, the ideal electrochemical condition was 0.2mA/cm²≤i<1mA/cm²,t>30min.The emissivity property of the top electrodes was deeply effected by polymeric conditions. The s of the top electrodes without applied potential increased when current density decreased or polymeric time extended, and had the lowest value when C_An:C_H2SO4 was1:2.The s of the top electrodes with applied minus potential was lower thanεwithout applied potential. The effect of positive potential to the e of the top electrode was indistinctive. Monomer concentration increasing or polymeric time extending would lead to the increase ofΔε,but the increase of the sulfuric acid concentration would cause the decrease of As. The prototypal IR-electrochromic devices exhibit an extreme durability, allowing them to be bent and twisted while in active operation without detriment, an optical memory, emittance value from 0.4 to 0.9, the maximum emittance vibration nearly 0.27, switching time at second level and cyclabilities of at least 50 cycles.