Related Experiment Video
Updated: Apr 4, 2026
In situ Grazing Incidence Small Angle X-ray Scattering on Roll-To-Roll Coating of Organic Solar Cells with Laboratory X-ray Instrumentation
Published on: March 2, 2021
Multi-region to single region shear thinning transitions in drying PEDOT:PSS dispersions: contributions from charge
Piramuthu Raja Ashok R1, Mathew Shaji Thomas1, Susy Varughese1
1Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai - 600036, India. susy@iitm.ac.in.
Abstract:
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.
