BUSCADOR RECOLECTA

Thin films of polymeric blends composed of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and polyethylene oxide (PEO) were investigated by varying the concentration of the two components over the entire range of compositions and the molecular weight of PEO. Phase separation and crystallization have been studied at different length scales by combining Atomic Force Microscopy (AFM) and Grazing Incidence Wide Angle X-ray Scattering (GIWAXS) using synchrotron light. Several different arrangements in the thin films of the two polymers constituting the blend were observed and discussed in detail, providing information about their reciprocal influence at the micro- and nano-scale. In addition to that, we were able to estimate quantitative nanomechanical and nanoelectrical properties via AFM and finally revealing the dependence of the thin films' physical properties on their composition and structure. By varying the blend composition, we achieved different coating capability, mechanical properties, and electrical conductivity. Furthermore, depending on the PEO molecular weight, the electrical response of the resulting blends’ thin films shows some differences. In the low range concentration, the blend thin films with high molecular weight PEO present coarser conducting paths than in those with the low molecular weight counterparts. For intermediate concentrations, a more effective phase segregation of PEDOT:PSS and PEO is achieved for high molecular weight PEO. These differences are also translated to different electrical conductivity., We acknowledge funding from the Spanish State Research Agency (AEI) through projects PID2019-107514 GB-I00/AEI/10.13039/501100011033 and PID2019-106125 GB-I00/AEI/10.13039/501100011033. We also acknowledge funding from Eusko Jaurlaritza (Basque Government) through the Grants IT-1566-22., Peer reviewed