Preparation And Properties Of PEDOT/Carbon Nanocomposite Electrochromic Materials

Electrochromism phenomenon is the reversible optical change of materials accompanying with various oxidation and reduction states in the AC electric field.Its most intuitive phenomenon is the color change at different voltages.Conductive polymer electrochromic materials possess rich color changes,good processability,and low cost,They are the most popular materials.In this dissertation,PEDOT was used to compound with different dimensional carbon nanomaterials,to prepare PEDOT/carbon nanocomposite electrochromic materials.The interfacial covalent bond was used to improve their electrochromic properties.The structure,electrochemical properties,and electrochromic properties of the material were studied:1.The conductive polymer PEDOT was prepared by constant potential method.By optimizing the polymerization conditions and the polymerization system,PEDOT film with dense structure was obtained.The test results show that the prepared PEDOT film has good electrochromic properties under the optimal polymerization conditions.2.One-dimensional structure of carbon nanotubes functionalized with thiophene groups was selected to prepare PEDOT/carbon nanotube composite electrochromic material with interfacial covalent bond.The test results show that the electrochromic properties of PEDOT and carbon nanotube composites are significantly better than pure PEDOT.As the percentage of carbon nanotubes increases,the contrast of the composite increases from 0.48 for pure PEDOT to 0.57 for 7%(PEDOT-CNT-7%),and the response speed increases to varying degrees.3.The two-dimensional structure of graphene containing thiophene functionalized group is also compounded with PEDOT.The test results show that the contrast increases with the increase of graphene content.However,the coloring time of the system decreased from 5.89 s of pure PEDOT to 4.13 s(PEDOT-GO-5%)and rose to 5.07 s(PEDOT-GO-7%).The fading time of the system decreased from 2.6 s of pure PEDOT to 1.93 s(PEDOT-GO-7%)due to the barrier effect of graphene on the ions.This barrier effect was only appeared with high loading amount of graphene was added.The covalent bond between the carbon nanomaterial and the conductive polymer can not only improve the electron conduction through the two-phase interaction,but also boost the ion transport and ion diffusion by adjusting the conjugated chain aggregation,Thereby the electrochromic properties of PEDOT/carbon nanomaterials are enhanced.