Dielectric spectroscopy of melt-extruded polypropylene and as-grown carbon nanofiber composites
Autor: | Y. Nioua, Mohammed Essaid Achour, Marcos Cerqueira, A. J. Paleo, N. Aribou, Z. Samir, M. S. Martins, J. Agostinho Moreira |
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Rok vydání: | 2021 |
Předmět: |
Polypropylene
Materials science Carbon nanofiber Constant phase element Biophysics 02 engineering and technology Surfaces and Interfaces General Chemistry Dielectric Chemical vapor deposition 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Dielectric spectroscopy chemistry.chemical_compound symbols.namesake chemistry symbols General Materials Science Composite material Nyquist plot 0210 nano-technology Raman spectroscopy Biotechnology |
Zdroj: | The European Physical Journal E. 44 |
ISSN: | 1292-895X 1292-8941 |
Popis: | In this work, different weight contents of as-grown carbon nanofibers (CNFs), produced by chemical vapor deposition, were melt-extruded with polypropylene (PP) and their morphologic, structure and dielectric properties examined. The morphologic analysis reveals that the CNFs are randomly distributed in the form of agglomerates within the PP matrix, whereas the structural results depicted by Raman analysis suggest that the degree of disorder of the as-received CNFs was not affected in the PP/CNF composites. The AC conductivity of PP/CNF composites at room temperature evidenced an insulator–conductor transition in the vicinity of 2 wt.%, corresponding to a remarkable rise of the dielectric permittivity up to $$\sim $$ 12 at 400 Hz, with respect to the neat PP ( $$\sim $$ 2.5). Accordingly, the AC conductivity and dielectric permittivity of PP/CNF 2 wt.% composites were evaluated by using power laws and discussed in the framework of the intercluster polarization model. Finally, the complex impedance and Nyquist plots of the PP/CNF composites are analyzed by using equivalent circuit models, consisting of a constant phase element (CPE). The analysis gathered in here aims at contributing to the better understanding of the enhanced dielectric properties of low-conducting polymer composites filled with carbon nanofibers. |
Databáze: | OpenAIRE |
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