Electrochemical and electrochromic properties of poly(4,4" dimethoxy 3'-methyl 2,2':5',2" terthiophene)

• Autor(a) principal: Dias,Bruna L.
• Data de Publicação: 2005
• Outros Autores: Girotto,Emerson M., Matos,Roberto de, Santos,Marcos J. L., De Paoli,Marco-A., Gazotti,Wilson A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532005000500009
• topic: thiophene derivatives; electrochromic properties; electro polymerization; electrochromism; conducting polymer

This work describes the electrochemical, spectroelectrochemical and electrochromic properties of poly(4,4" dimethoxy 3'-methyl 2,2':5',2" terthiophene) thin films. The effect of temperature on the electropolymerization was studied by cyclic voltammetry measured in situ. The temperatures used were -10, 0, 10, 20, and 40 ºC. Results indicate that the electropolymerization temperature directly affect the degree of chain organization. The optical response time for bleaching was 0.8 s and for coloring 0.3 s (for films synthesized at 40 ºC, 60 nm thick). After 1400 electrochromic cycles, the chromatic contrast at 570 nm changes from 31 to 14%. The coloration efficiency was enhanced as a function of redox cycling. This was probably caused by a decrease in the injected charge necessary for the color change, suggesting that the electroactive losses occurring during the cycles are related to sites not responsible for electrochromic contrast.