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Registro Completo |
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Biblioteca(s): |
Embrapa Instrumentação. |
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Data corrente: |
22/12/1999 |
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Data da última atualização: |
02/07/2013 |
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Autoria: |
MALMONGE, J. A.; CAMPOS, M. S. de; MATTOSO, L. H. C. |
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Afiliação: |
UNESP-Campus de Ilha Solteira; EMBRAPA-CNPDIA. |
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Título: |
Absorption spectra of thin films of poly (o-methoxyaniline) irradiated by X-ray. |
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Ano de publicação: |
1997 |
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Fonte/Imprenta: |
In: ENCONTRO NACIONAL DE FISICA DA MATERIA CONDENSADA, 20., jun. 1997, Caxambu, MG. Resumos... Sao Paulo: Sociedade Brasileira de Fisica, 1997. |
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Páginas: |
p. 317. |
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Idioma: |
Inglês |
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Conteúdo: |
The adsorption spectra of thim film of poly(o-methoxyaniline)(POMA), chemically synthesized, coated on quartz slides by dip coating from chloroform solution were measured as a function of irradiation dose. The UV-Vis Nir absorption analysis showed that unirradiated films(emeraldine base) presents two adsorption peaks at about 320nm and about 620nm assigned respectively to PI - PI and excitonic transitions. Upon irradiation, under 50% RH, we have observed that the intensity of the first (about 320nm) and second (about 620nm) peaks decrease while the intensity of two new peaks at 840nm and 430nm increase as function of irradiated dose. The same behavior is found when polyanilines are conventionally doped with inorganic acids. These two new absorption bands are consistent with an increase in the mobility of the charge carriers, i.e. doping of the polymers to the conductive regime. After 230kGy of radiation dose, we observed that absorption at 620 disappeared and the absorption at 840nm and 430nm had reached the maximum. The irradiated film was dedoped with 0.1M NH-4OH and its spectra of absorption was similar to unirradiated film. This same reversible process occurs to polyanilines doped with inorganic acid. The electrical conductivity measured by four probe increases from about 10E-10 S/cm (unirradiated films) to 10E-10 S/cm (irradiated fims). The conductivity reached for polyanilines was 0.5S/cm. We have also observed that conductivity increases as a function of radiation dose and humidity level, and that water plays an important role on doping induced by X-ray radiation. MenosThe adsorption spectra of thim film of poly(o-methoxyaniline)(POMA), chemically synthesized, coated on quartz slides by dip coating from chloroform solution were measured as a function of irradiation dose. The UV-Vis Nir absorption analysis showed that unirradiated films(emeraldine base) presents two adsorption peaks at about 320nm and about 620nm assigned respectively to PI - PI and excitonic transitions. Upon irradiation, under 50% RH, we have observed that the intensity of the first (about 320nm) and second (about 620nm) peaks decrease while the intensity of two new peaks at 840nm and 430nm increase as function of irradiated dose. The same behavior is found when polyanilines are conventionally doped with inorganic acids. These two new absorption bands are consistent with an increase in the mobility of the charge carriers, i.e. doping of the polymers to the conductive regime. After 230kGy of radiation dose, we observed that absorption at 620 disappeared and the absorption at 840nm and 430nm had reached the maximum. The irradiated film was dedoped with 0.1M NH-4OH and its spectra of absorption was similar to unirradiated film. This same reversible process occurs to polyanilines doped with inorganic acid. The electrical conductivity measured by four probe increases from about 10E-10 S/cm (unirradiated films) to 10E-10 S/cm (irradiated fims). The conductivity reached for polyanilines was 0.5S/cm. We have also observed that conductivity increases as a function of radiation dos... Mostrar Tudo |
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Palavras-Chave: |
filmes; polímeros. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02187naa a2200181 a 4500
001 1027261
005 2013-07-02
008 1997 bl --- 0-- u #d
100 1 $aMALMONGE, J. A.
245 $aAbsorption spectra of thin films of poly (o-methoxyaniline) irradiated by X-ray.
260 $c1997
300 $ap. 317.
520 $aThe adsorption spectra of thim film of poly(o-methoxyaniline)(POMA), chemically synthesized, coated on quartz slides by dip coating from chloroform solution were measured as a function of irradiation dose. The UV-Vis Nir absorption analysis showed that unirradiated films(emeraldine base) presents two adsorption peaks at about 320nm and about 620nm assigned respectively to PI - PI and excitonic transitions. Upon irradiation, under 50% RH, we have observed that the intensity of the first (about 320nm) and second (about 620nm) peaks decrease while the intensity of two new peaks at 840nm and 430nm increase as function of irradiated dose. The same behavior is found when polyanilines are conventionally doped with inorganic acids. These two new absorption bands are consistent with an increase in the mobility of the charge carriers, i.e. doping of the polymers to the conductive regime. After 230kGy of radiation dose, we observed that absorption at 620 disappeared and the absorption at 840nm and 430nm had reached the maximum. The irradiated film was dedoped with 0.1M NH-4OH and its spectra of absorption was similar to unirradiated film. This same reversible process occurs to polyanilines doped with inorganic acid. The electrical conductivity measured by four probe increases from about 10E-10 S/cm (unirradiated films) to 10E-10 S/cm (irradiated fims). The conductivity reached for polyanilines was 0.5S/cm. We have also observed that conductivity increases as a function of radiation dose and humidity level, and that water plays an important role on doping induced by X-ray radiation.
653 $afilmes
653 $apolímeros
700 1 $aCAMPOS, M. S. de
700 1 $aMATTOSO, L. H. C.
773 $tIn: ENCONTRO NACIONAL DE FISICA DA MATERIA CONDENSADA, 20., jun. 1997, Caxambu, MG. Resumos... Sao Paulo: Sociedade Brasileira de Fisica, 1997.
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Embrapa Instrumentação (CNPDIA) |
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| 1. |  | GARCIA, L. G.; SALEMI, L. F.; MINGOTI, R.; CASSIANO, C. C.; FRANSOZI, A. A.; FARIA, V. G. DE; VETTORAZZI, C. A.; LIMA, W. L.; FERRAZ, S. F. DE B. Hydrological effects of spatial harvest patterns in a small catchment Covered by fast-growing plantations in the neotropics. Advances in Environmental and Engineering Research, v. 4, n. 1, p. 1-17, 2023.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: C - 0 |
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| 2. | | COUTO JUNIOR, A.; MARTINS, P.; SANO, E. E.; MARTINS, E. de S.; VIEIRA, L.; SALEMI, L.; VASCONCELOS, V. Data for: Terrain units, land use/cover, and gross primary productivity of the largest fluvial basin in the Brazilian Amazonia/Cerrado ecotone: The Araguaia River Basin. Data in Brief, v. 34, 106636, 2021.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: B - 1 |
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| 3. | | MARTINS, P. R.; SANO, E. E.; MARTINS, E. de S.; VIEIRA, L. C. G.; SALEMI, L. F.; VASCONCELOS, V.; COUTO JÚNIOR, A. F. Terrain units, land use and land cover, and gross primary productivity of the largest fluvial basin in the Brazilian Amazonia/Cerrado ecotone: The Araguaia River basin. Applied Geography, v. 127, 102379, 2021.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
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| 4. | | NOGUEIRA, S. F.; PAULA, A. M. de; PEREIRA, B. F. F.; SALEMI, L. F.; FONSECA, A. F. da; MONTES, C. R.; VICTORIA, R. L. Water type and irrigation time effects on microbial metabolism of a soil cultivated with Bermuda-grass Tifton 85. Brazilian Archives of Biology and Technology, v. 54, n. 3, p. 477-486, may/jun. 2011.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: B - 1 |
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