High-frequency dielectric response of polyaniline pellets as nanocomposites of metallic emeraldine salt and dielectric base

0448157 - FZÚ 2016 RIV CH eng J - Journal Article
Nuzhnyy, Dmitry - Petzelt, Jan - Rychetský, Ivan - Trchová, Miroslava - Stejskal, Jaroslav
High-frequency dielectric response of polyaniline pellets as nanocomposites of metallic emeraldine salt and dielectric base.
Synthetic Metals. Roč. 209, Nov (2015), s. 561-569. ISSN 0379-6779. E-ISSN 0379-6779
R&D Projects: GA ČR GAP204/12/0232; GA ČR(CZ) GAP205/12/0911
Institutional support: RVO:68378271 ; RVO:61389013
Keywords : polyaniline * infrared and THz spectroscopy * optical conductivity * dielectric permittivity * vibrational mode * effective medium approach
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 2.299, year: 2015

Conducting polyaniline (PANI) salt and dielectric PANI base pellets were studied in the infrared (IR) and terahertz (THz) range at room temperature and compared with the IR transmission spectra of powdered samples dispersed in potassium bromide and with those of thin films. The IR reflectivity combined with THz transmission was fitted to calculate the permittivity and IR conductivity spectra. Good agreement between the IR conductivity peaks and those from the absorbance evaluated from the transmission measurements was obtained and differences between the spectra of PANI salt and base are discussed. The dielectric and conductivity spectra of PANI salt were modeled as the spectra of a composite of PANI base and metallic PANI. Effective medium approach using three different models was applied and discussed. The best results, including the semiconductor-like temperature dependence of the low-frequency conductivity, were obtained with the generalized Lichtenecker model.
Permanent Link: http://hdl.handle.net/11104/0249877