Photoelectrical properties in poly(alkyl/alkoxy-terthiophenes): dependence on the alkyl-chain length

Casalbore-Miceli, G.; Camaioni, Nadia; Gallazzi, M. C.; Albertin, Luca; Fichera, A.M.; Geri, A.; Girotto, Emerson M.

doi:10.1016/s0379-6779(01)00488-x

Cited by 17 publications

(14 citation statements)

References 11 publications

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“…As mentioned, the electrochemical and spectroelectrochemical properties of polyterthiophenes are dependent on the side group length, which leads to changes in their absorption spectra and redox properties. 26 Larger intermolecular interactions provide smaller energy gap transitions and increases light harvesting. 43,44 However, in our case, PDM does not present a smaller E gap , 22 despite its larger light harvesting.…”

Section: Resultsmentioning

confidence: 99%

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Effect of synthesis temperature and alkoxy side chain length on molecular structure and photoelectrochemical properties of terthiophenes

Santos¹,

Girotto²

2009

J. Braz. Chem. Soc.

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Section: Resultsmentioning

confidence: 99%

“…26 All reagents were reagent-grade quality and used without further purification. Acetonitrile (AN Merck) was stored under argon pressure and manipulated under argon flow.…”

Section: Methodsmentioning

confidence: 99%

Effect of synthesis temperature and alkoxy side chain length on molecular structure and photoelectrochemical properties of terthiophenes

Santos¹,

Girotto²

2009

J. Braz. Chem. Soc.

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“…22,23 This method presents important advantages such as preparation of polymer films with controlled thickness, directly from the monomer solution. 18 Moreover, the degree of polymerization can be improved by careful selection of the electropolymerization parameters. [23][24][25][26][27] The electrosynthesized pDMTT films (ca.…”

Section: Synthesis Of Pdmttmentioning

confidence: 99%

“…According to Casalbore-Miceli et al, this thiophene class shows a strong dependence of the maximum absorbance wavelength and oxidation peak potential on the alkyl chain length. 18 In another recent work, it was demonstrated that the maximum absorption wavelength of poly{3-[12-(p-methoxyphenoxy)-alkyl]thiophene}also depends on the alkyl chain length of the substituted monomer. 19 Aiming to contribute towards understanding how the synthesis method affects the electrochemical and electrochromic properties of substituted terthiophenes, the present work reports the electrochemical and electrochromic characterization of a polymer obtained from a terthiophene derivative, poly(4,4"-dimethoxy-3'-methyl-2,2':5',2"-terthiophene), taking into consideration the synthesis temperature and the electrochromic stability.…”

Section: Introductionmentioning

confidence: 99%

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

Dias¹,

Girotto²,

Matos³

et al. 2005

J. Braz. Chem. Soc.

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Este trabalho descreve o estudo das propriedades eletroquímicas, espectroeletroquímicas e eletrocrômicas de filmes finos de poli(4,4" dimetoxi 3'-metil 2,2':5',2" tertiofeno). A voltametria cíclica in situ foi usada para estudar o efeito da temperatura sobre a eletropolimerização. As temperaturas utilizadas na deposição eletroquímica foram -10, 0, 10, 20 e 40 o C. Os resultados indicaram que a temperatura de eletropolimerização afeta diretamente o grau de ordenamento molecular do polímero. O tempo de resposta eletrocrômico foi de 0,8 s para clareamento e 0,3 s para escurecimento (para filmes sintetizados a 40 o C, espessura de 60 nm). Após 1400 ciclos eletrocrômicos, o contraste óptico a 570 nm diminuiu de 31 para 14%. A eficiência eletrocrômica foi intensificada em função do número de ciclos eletrocrômicos. Este fato foi provavelmente causado pela diminuição da carga injetada, necessária para a mudança de cor, sugerindo que as perdas na eletroatividade estão associadas a sítios que não são responsáveis pela mudança de coloração.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 o C. 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 o C, 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.

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“…2,7,8 Study of the interaction between polymer and dopant is meaningful for the comprehension and applications of these materials. 9 The literature have demonstrated the application of electroactive conjugated polymers in the solar cells development, 10,11 organic light-emitting devices, 12,13 and electrochromic and electrochemical devices. [14][15][16][17] Among this applications, the use of electroactive conducting polymers in pH sensing technology has been the focus of many studies in the last decade.…”

Section: Introductionmentioning

confidence: 99%

pH effects on the ohmic properties of bromophenol blue-doped polypyrrole film

Ferreira

Girotto

2010

J. Braz. Chem. Soc.

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A resposta ôhmica durante medidas de resistência in situ de filmes de polipirrol (ppy) dopados com azul de bromofenol (BPB) foi analisada para se estudar o efeito do pH nas propriedades analíticas dos filmes. As moléculas de BPB foram inseridas na matriz polimérica através de síntese eletroquímica sobre eletrodos digitalizados de ouro. Os filmes de ppy-BPB não apresentaram diminuição da resistência ôhmica linear com relação ao aumento do pH do meio, no intervalo de 1,5 a 11, sendo observado um aumento da resistência do filme após imersão em pH 7,5. O comportamento não linear é uma desvantagem para a aplicação do ppy-BPB como sensor de pH, no entanto, importantes informações sobre a interação entre o dopante e o polímero conjugado podem ser obtidas deste sistema. O comportamento ôhmico do filme de ppy-BPB pode ser explicado em termos da variação no equilíbrio entre as formas neutra e aniônica do corante preso na matriz de ppy. O estudo neste trabalho contribui para o desenvolvimento de sensores eficientes baseados em polímeros condutores.The ohmic response of bromophenol blue (BPB) doped polypyrrole (ppy) films obtained by in situ resistance measurements was studied to evaluate the pH effect on their analytical properties. BPB molecules were inserted into the ppy matrix by electrochemical synthesis onto digitized gold electrodes. Ppy-BPB films do not present decrease in the linear ohmic resistance when increasing pH values over the pH range 1.5-11.0, displayed by an increase in resistance after immersion in pH 7.5. The nonlinear behavior is a disadvantage for the application of the ppy-BPB film as pH sensor, however, meaningful information about the interaction between the dopant and the conjugated polymer can be obtained from the system. The ohmic behavior of the ppy-BPB films are explained in terms of the equilibrium between neutral and anionic dye species embedded in the ppy matrix. This work brings important contributions to the development of efficient conducting polymer-based sensors.Keywords: polypyrrole, bromophenol blue, ohmic properties, doped films IntroductionConducting polymers are well known materials with interesting optical, magnetic and electrical properties. 1-3The oxidation process in the electronic structure of a heterocyclic conjugated polymer, such as polypyrrole (ppy), 4,5 leads to the formation of polaron and bipolaron states. These energy states are related to remarkable properties of conjugated polymers that take place with the introduction of anion dopants into the polymer matrix to stabilize those charges (polaron and bipolaron) formed during oxidation. 6 The dopant used during the polymer synthesis can directly affect the electrical and structural properties of the conjugated polymer. 2,7,8 Study of the interaction between polymer and dopant is meaningful for the comprehension and applications of these materials. 9The literature have demonstrated the application of electroactive conjugated polymers in the solar cells development, 10,11 organic light-emitting devices, 12,13 and electro...

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Photoelectrical properties in poly(alkyl/alkoxy-terthiophenes): dependence on the alkyl-chain length

Cited by 17 publications

References 11 publications

Effect of synthesis temperature and alkoxy side chain length on molecular structure and photoelectrochemical properties of terthiophenes

Effect of synthesis temperature and alkoxy side chain length on molecular structure and photoelectrochemical properties of terthiophenes

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

pH effects on the ohmic properties of bromophenol blue-doped polypyrrole film

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