Enhancing Conductivity of PEDOT:PSS by Blending PEO in Films and Jets: A Combined Ab Initio Modeling and Experimental Study

The rapid advancement of innovative organic-based technologies has led to significant development of various electronic devices. Conducting polymers in blends with non-conducting polymers acquire viscoelasticity sufficient for direct ink writing (DIW) of conducting circuits on knitted and nonwoven materials. In this regard, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) in blends with poly(ethylene oxide) (PEO) posses beneficial properties, excellent thermal stability and processability. In this study, a combination of ab initio modeling and experimental analysis is presented to investigate the electronic conductivity of composed PEDOT:PSS/PEO films. Ab initio DFT calculations are performed based on experimental data to unveil the band structure and density of states of the composite materials. Various polymer compositions with varying PEDOT, PSS, and PEO ratios are examined, revealing unexpected electronic properties of these polymer blends. Notably, the addition of PEO results in a significant change in the band gap, particularly near the maximum PEO content of 52 weight-%. These findings are consistent with our own measurements of film conductivity. This combined modeling and experimental approach provides a mechanistic interpretation of the underlying reasons behind the variations in polymer blends conductivity and opens way for synthesizing highly-conducting polymers for extrusion-based manufacturing techniques such as DIW .