Study On The Synthesis And Electrochromic Properties Of Organic Polymers Containing Dithiophene

Electrochromism is known as the alternative changes of colors by the application of voltages.This interesting phenomenon has led to its applications in many technological fields such as smart windows,automatic antiglazing mirrors,large-scale electrochromic screens,and chameleon materials.Derivatives of triphenylamine?TPA?,including small molecules,dendrimers,star compounds or polymers with TPA units in the polymer backbone or in pendant groups,are among the most widely used electrochromic materials.In this paper,a new series of organic materials and polymers containing thiophenes and triphenylamine?TPA?derivatives were synthesized and characterized by NMR,FTIR and EA.Meanwhile,we further explored their electrochromic and photovoltaic properties.In the first part,a new series of aromatic amides?AAs?containing thiophenes and triphenylamine?TPA?derivatives were designed and synthesized.The AAs exhibited excellent solubility in common organic solvents and displayed good thermal stabilities.All obtained AAs revealed multicolor reversible electrochemical characteristics?original yellowish to green or original yellowish to green until purple occurred?and excel ent stability of electrochromic and photovoltaic properties.In the second part,three new compounds containing 3.4-dithienylpyrrole?DTP?and TPA derivatives were designed and synthesized.The polymers PDTP-TPA-ns?n=1,2,3?were prepared by electropolymerization from DTP-TPA-ns.The polymer exhibited reversible multicolor in the visible and NIR region?original yellowish to green until dusty blue occurred?.After over 100 s electrochromic switches,the polymers films still exhibited reversible redox process and good stability of electrochromic characteristicsIn the third part,the pure polymer limits the range of applications due to its low electronic charge transmission performance,low coloration switching efficiency,slow coloration changing rate.The well aligned TiO₂ nanotube arrays were prepared by electrochemical anodization,which had the special nanometer pore structure and excellent electrochemical properties.In the present article,under optimized conditions,TiO₂ nanotube electrode with electrochromic materials are completely transparent and can allow electrochromic test.The results show remarkable electrochemical properties and fast electrochromic reponse time.This paper has provided some methods and ideas for design and synthesis a new type of multifunctional polymer materials and a certain theoretical support to understand the electrochromic mechanism of multi-functional polymer.