Impact of Stir Rate during Polymerization on the Properties of PEDOT:PSS


  • Julian Alberto, Chemical Engineering, University of Delaware

Faculty Mentor(s)

  • Laure Kayser, Materials Science & Engineering, University of Delaware


Title: Impact of Stir Rate during Polymerization on the Properties of PEDOT:PSS

Authors: Julian Alberto, Dr. Laure V. Kayser, Vidhika Damani

Affiliation: Kayser Lab, Materials Science & Engineering, University of Delaware


Conducting polymers are organic conductors or semiconductors that can transport both ions and electrons. One such material is Poly(3,4-ethylenedioxythiophene): Polystyrene Sulfonate (PEDOT:PSS), a conductive polyelectrolyte complex which shows high conductivity, stability in water and oxygen, and commercial availability. Current challenges with the production of PEDOT:PSS include the ability to produce at scale while maintaining consistent electronic and viscous properties throughout. One method of synthesizing this complex is the oxidative polymerization of EDOT in the presence of PSS, dissolved in water. This method of synthesis has been studied greatly, however there are few known factors that contribute to the variation in properties of this material. This experimental study focuses on investigating the impact of reaction stir rate during the polymerization process and its effect on the electronic and viscous properties of PEDOT:PSS. A series of PEDOT:PSS samples were synthesized under controlled conditions while varying the reaction stir rate. The stirring rates were set at different levels, ranging from 400 rpm to 1000 rpm, and the resulting PEDOT:PSS samples were characterized for conductivity. To evaluate the electronic properties of the samples, electronic conductivity measurements were performed using a four-point probe attached to a Keithley ohmmeter. The electronic conductivity of the PEDOT:PSS was measured to determine if the rate of stirring affects the degree of polymerization and chain alignment within the PEDOT:PSS matrix, thereby influencing its electrical transport properties. Additionally, the viscous properties of the PEDOT:PSS samples will be examined using rheology. These results should reveal a relationship between variations in reaction stir rate and the viscous properties of the bulk material. These findings contribute to the design and fabrication of PEDOT:PSS-based materials with tailored characteristics for diverse applications such as organic electronic devices, flexible electronics, and biomedical sensors. Understanding the influence of reaction stir rate opens new avenues for optimizing PEDOT:PSS synthesis protocols to attain superior performance in a wide range of technological applications.