Chemical Polymerization And Electrochromic Study Of Conjugated Polymers Based On 3,4-propylenedioxythiophene Or Carbazole Units

Conducting polymers have a long history.In the recent years,it has been widely studied by scientists to apply conducting polymers into the filed of electrochromism,and they have made great progress.The electrochromic materials made with conducting polymers have many excellent properties,for example,high optical contrast,fast response time,high coloration efficiency,good thermal stability,low cost and so on.The inchoate electrochromic materials were made with inorganic substance,including NiO,WO3 and so on.The polymers inject and extract electron under the action of applied potential,this change the valence structure or crystal structure of thin film,and so as to realize the reversible change of coloring and fading.Inorganic field effect transistor was made of this type materials.At present,the electrochromic materials based on organic conducting polymers were most widely studied,these materials realize their function of color change via doping and dedoping.The conducting polymers have succefully been applied in the light-emitting diodes,solar cells,smart window,sensors,optical display etc.So our target is to design and synthesis electrochromic materials with outstanding characters which based on conducting polymers.In chapter 2,three D-A type polymers P1,P2,P3 based on isoindigo?IID?,propylenedioxythiophene?ProDOT?and thiophene were designed and synthesied successfully using the method of Stille coupling polymerization.And a series of chemical analysis methods have been adopted in order to test the structure and character of these polymers.Rusults showed that the color of P1 is cadetblue in the neutral state,while the color of P2 and P3 are black in the neutral state,P1 is darkgray in the oxidation state,while P2 and P3 are transparent gray in the oxidation state.The onset oxidation potential?Eonset?of P1,P2,P3 are 0.70 V,0.65 V,0.57 V respectively.The Eg of P1,P2,P3 are 1.39 eV,1.37 eV,1.27 eV respectively,they all at a low level,this is what we have expected.The response time and coloration efficiency of P1 at 1600 nm is 0.45 s and 162.49 cm²·C^-respectively,the response time and coloration efficiency of P2 at 1500 nm is 0.38 s and 181.73 cm²·C^-respectively,the response time and coloration efficiency of P1 at 1330 nm is 0.77 s and 96.88 cm²·C^-respectively,they all have excellent electrochromic properties.In chapter 3,PDDID-1,PDDID-2,PDDID-3 were successfully designed and synthesied through the method of Stille coupling polymerization,and further tests were also carried out in order to study their properties.The color of PDDID-1,PDDID-2,PDDID-3 are palevioletred,rosybrown,atrovirens in the neutral state and darkgray,silver,lightgrey in the oxidation state respectively.The onset oxidation potential?Eonset?of PDDID-1,PDDID-2,PDDID-3 are 0.72 V,0.73 V,0.75 V respectively.The band gap?Eg?of PDDID-1,PDDID-2,PDDID-3 are 1.44 eV,1.46 eV,1.48 eV respectively.The response time and coloration efficiency of PDDID-1 at 1550 nm is 0.78 s and 210.76 cm²·C^- respectively,the response time and coloration efficiency of PDDID-2 at 1500 nm is 0.60 s and 283.45 cm²·C^- respectively,the response time and coloration efficiency of PDDID-3 at 1500 nm is 1.50 s and 304.58 cm²·C^- respectively.In chapter 4,we synthesied two polymers PDDBD-1,PDDBD-2 through Stille coupling polymerization,then we conducted a series of representation of them.The color of PDDBD-1 are lilac in the neutral state and reseda in the oxidation state,while PDDBD-2 are green in the neutral state and light brown in the oxidation state.The onset oxidation potential?Eonset?of PDDBD-1 is 0.89 V,the band gap?Eg?of PDDBD-1 is 1.39 eV.The response time and coloration efficiency of PDDBD-1 at 1600 nm is 2.98 s and 146.55 cm²·C^-.The onset oxidation potential?Eonset?of PDDBD-2 is 0.93 V,the band gap?Eg?of PDDBD-2 is 1.51 eV.The response time and coloration efficiency of PDDBD-2 at 1620 nm is 3.07 s and 229.73 cm²·C^-,they all show great electrochromic properties.In chapter 5,two newfashioned D-A type polymers PDTCZ-1,PDTCZ-2 were synthesied also use the Stille coupling polymerization,the color of PDTCZ-1,PDTCZ-2 are sea green and forest green respectively in the neutral state,moderate aquamarine and Light goldenrodyellow respectively in the oxidation state respectively.The onset oxidation potential?Eonset?of PDTCZ-1,PDTCZ-2 are 0.78 V and 0.70 V respectively.The band gap?Eg?of PDTCZ-1,PDTCZ-2 are 1.44 eV,1.34 eV respectively.The response time and coloration efficiency of PDTCZ-1 at 1530 nm is 0.65 s and 197.86 cm²·C^- respectively,the response time and coloration efficiency of PDTCZ-2 at 1630 nm is 2.87 s and 84.77 cm²·C^-respectively.