The DC conductivity and Hall effect studies were used to investigate the nature, type, and development of the charge carriers in conductive polymer composite containing PAN-based carbon fibers of different concentration. The dependence of the electrical conductivity on temperature is characterized by a two-stage electrical conduction process with a semiconducting type of behavior and two activation energies. It was found the measured Hall voltage varies linearly with Hall current with two different signs of slopes. This suggests that a composite of low fiber content is functioning as p-type material, and then changes to n-type with increasing the carbon fiber content more than 15 wt.%. The density of the charge carriers increases with carbon fiber content in a behavior similar to the electrical conductivity for all given composites, showing a percolation phenomenon. The calculated charge carriers density includes both the magnetostatic arising from the polycarbonate matrix and from the free charge carriers themselves. Considering the filled carbon fibers as a random semiconducting material, the results obtained for various composites were described in terms of the band structure model. Other approach of results analysis was based on the composite bulk morphology observed by the SEM microscopy.
A Study on the DC Electrical Properties of PAN-based Carbon Fiber/Polycarbonate Composites
G Ragosta
2007
Abstract
The DC conductivity and Hall effect studies were used to investigate the nature, type, and development of the charge carriers in conductive polymer composite containing PAN-based carbon fibers of different concentration. The dependence of the electrical conductivity on temperature is characterized by a two-stage electrical conduction process with a semiconducting type of behavior and two activation energies. It was found the measured Hall voltage varies linearly with Hall current with two different signs of slopes. This suggests that a composite of low fiber content is functioning as p-type material, and then changes to n-type with increasing the carbon fiber content more than 15 wt.%. The density of the charge carriers increases with carbon fiber content in a behavior similar to the electrical conductivity for all given composites, showing a percolation phenomenon. The calculated charge carriers density includes both the magnetostatic arising from the polycarbonate matrix and from the free charge carriers themselves. Considering the filled carbon fibers as a random semiconducting material, the results obtained for various composites were described in terms of the band structure model. Other approach of results analysis was based on the composite bulk morphology observed by the SEM microscopy.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
