R PRA, Thomas MS, Varughese S. Multi-region to single region shear thinning transitions in drying PEDOT:PSS dispersions: contributions from charge density fluctuations.
SOFT MATTER 2015;
11:8441-8451. [PMID:
26360769 DOI:
10.1039/c5sm01000d]
[Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
UNLABELLED
The multiple shear thinning behaviour observed in dispersions of the conducting polymer, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (
PEDOT
PSS), in water during the drying process is explored.
PEDOT
PSS dispersions in water can be non-stoichiometric polyelectrolyte complexes (PECs) with free polyanion (PSS) chains resulting in scrambled egg conformations. They also behave as charged colloidal particles. The behaviour of
PEDOT
PSS dispersions as PECs and charged colloidal systems during drying is analyzed using rheology and TEM, zeta potential, conductivity, pH, dynamic light scattering (DLS) and rheo-small angle light scattering (rheo-SALS) information. The rheological behaviour is found to have significant contributions from conformational changes in the
PEDOT
PSS PEC due to charge density fluctuations affecting the electrostatic persistence length, le. A low concentration regime with multiple shear thinning behaviour and a high concentration regime with single shear thinning behaviour were observed. The PEC behavior of
PEDOT
PSS is further explored by charge neutralizing the dispersions with salts.
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