Study of optical absorption differences of doped polyaniline films by photothermal spectroscopies

In this work, we studied the optical absorption spectral differences between doped and slightly doped polyaniline films and a derivative by photopyroelectric and photoacoustic spectroscopies. There exist great spectral differences between doped and slightly doped samples as shown by conventional opt...

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Detalles Bibliográficos
Autores: Albuquerque, J. E. de, Melo, W. L. B., Faria, R. M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2007
País:Brasil
Institución:Universidade Federal de Viçosa (UFV)
Repositorio:LOCUS Repositório Institucional da UFV
Idioma:inglés
OAI Identifier:oai:locus.ufv.br:123456789/22219
Acceso en línea:https://doi.org/10.1007/s00339-007-4161-z
http://www.locus.ufv.br/handle/123456789/22219
Access Level:acceso abierto
Palabra clave:PANI
Photoacoustic spectroscopy
Emeraldine base
POMA
Chopper frequency
Descripción
Sumario:In this work, we studied the optical absorption spectral differences between doped and slightly doped polyaniline films and a derivative by photopyroelectric and photoacoustic spectroscopies. There exist great spectral differences between doped and slightly doped samples as shown by conventional optical absorption spectroscopy, but not greatly evidenced by photopyroelectric spectroscopy. The latter was applied to obtain thermal parameters such as thermal diffusivity and thermal conductivity, and as a result it showed that these thermal properties of polyaniline films are very similar for doped and slightly doped samples. Also it showed that for thicker films (about 20 μm), there are no significant optical absorption differences between them. However, for thin films both techniques showed greater optical absorption differences for doped and slightly doped samples, mainly detected by photoacoustic spectroscopy. These behaviors are in accordance with published results which is the granular metal model for polyaniline. This model explains the polyaniline polymeric matrix as formed by conductive islands in the insulating bulk material.