Amphiphilic poly(vinyl chloride)-g-poly(oxyethylene methacrylate) graft polymer electrolytes: Interactions, nanostructures and applications to dye-sensitized solar cells

An amphiphilic graft copolymer, i.e. poly(vinyl chloride)-graft-poly(oxyethylene methacrylate) (PVC-g-POEM) comprised of a PVC backbone and POEM side chains was synthesized via atom transfer radical polymerization (ATRP) and complexed with a salt for dye-sensitized solar cell (DSSC) applications. The coordinative interactions and structural changes of polymer electrolytes were investigated using FT-IR spectroscopy, wide angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC). Small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) revealed that the d-spacing between PVC domains was significantly increased upon the introduction of metal salt, ionic liquid and oligomer, indicating their selective confinement in the hydrophilic POEM domains. The ion-conducting POEM domains were well interconnected, resulting in high ionic conductivity (∼10−4 S/cm at 25 °C) and energy conversion efficiency (∼5.0% at 100 mW/cm2) in the solid-state.