Effect of microstructure on the dielectric properties of poly(vinyl alcohol)-poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) composite films

摘要

Poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT-PSS) was blended with poly(vinyl alcohol) (PVA) to form 0, 10, 20, 30, 40, and 50 vol PEDOT-PSS/PVA solutions, and their freestanding films were prepared with a simple and cost-effective solution casting technique at 27 degrees C in the absence of additives. Field emission scanning electron microscopy images revealed changes in the cocontinuous network to a rodlike morphology in the composite films from 10 to 50 vol PEDOT-PSS/PVA. The alternating-current conductivity was found to obey Jonscher's power law. The obtained values of the dielectric constant at 27 degrees C were relatively high, and a maximum value of 6.7x10(4) at 100Hz for 40 vol PEDOT-PSS'/PVA was observed. The dielectric loss attained a maximum value of about 10(6) at 100Hz for 40 vol PEDOT-PSS/PVA. However, a decrease in the dielectric parameters was observed at 50 vol PEDOT-PSS/PVA because of locally induced strain in the microstructure. The variations in polarization with respect to the applied electric field (P-E) were determined for 50, 100, and 500Hz at 500V for the freestanding composite films of lower concentrations up to 20 vol PEDOT-PSS/PVA. In summary, the dielectric and P-E measurements confirmed that the electrical characteristics changed in accordance to the contribution from both resistive and capacitive sites in the PEDOT-PSS/PVA composites. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45079.