Premium
Relaxation and charge transport in mixtures of zwitterionic polymers and inorganic salts
Author(s) -
Rozanski Stanislaw A.,
Kremer Friedrich,
Köberle Peter,
Laschewsky André
Publication year - 1995
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1995.021960316
Subject(s) - conductivity , dielectric , chemistry , activation energy , arrhenius equation , relaxation (psychology) , dielectric spectroscopy , polymer , analytical chemistry (journal) , charge carrier , ionic conductivity , materials science , electrode , electrochemistry , organic chemistry , psychology , social psychology , electrolyte , optoelectronics
Dielectric spectroscopy is employed to analyze the molecular dynamics and the charge transport in mixtures of zwitterionic polymers of the type poly{3 [N(ω‐methacryloyloxyalkyl)] N , [ N ‐dimethylammonio propanesulfonate] with sodium iodide in the frequency range of 10 2 Hz–10 7 Hz and in the temperature range of 110 K‐400 K. The amount of inorganic salt added varies from 0–200 mol‐% relative to the number of zwitterionic groups present in the polymer, contributing strongly to the conductivity. One relaxation process is observed whose relaxation rate depends strongly on the length of the aliphatic spacer between the polymethacrylate main chain and the zwitterionic group. Exhibiting an Arrhenius‐like temperature depence with activation energy E A = 47 KJ/mol, this relaxation process is assigned to fluctuation of the quaternary ammonium groups in the side chains. At higher temperatures, the dielectric properties and the conductivity are primarily dominated by the mobile inorganic ions: conductivity strongly depends on the salt concentration, showing a pronounced electrode polarization effect. The frequency and salt concentration, dependences of the conductivity can be quantitatively described as hopping of charge carriers being subject to spatially randomly varying energy barriers. For the low‐frequency regime and for the critical frequency marking the onset of the conductivity's dispersion, the Barton‐Nakajima‐Namikawa (BNN) relationship is fulfilled.