Influence of polyethylene glycol plasticizer on the structural and electronic properties of PEO-NaI complex: a density functional study.

Ab initio study has been carried out to investigate the influence of low molecular weight polyethylene glycol (PEG) plasticizer on structural and electronic properties of the polyethylene oxide-sodium iodide (PEO-NaI) polymer-metal complex. DOS and PDOS analysis provided a quantitative explanation of the electronic bandgap of the PEO-NaI and PEO-PEG-NaI system. Hirshfeld population charge analysis (HPA) explains better dissociation of NaI in presence of polyethylene glycol, based on the Hard Soft Acid Base Principle. Also, an increase in amorphic content of polymer system is observed with the addition of PEG, evident from the increment in the strength of anti-bonding orbitals in COOP plot. Bond strength of the polymeric system is also found to be affected with the addition of plasticizer. The findings provide an avenue that the present polymer system [PEO-PEG-NaI] is a potential candidate to be used as an electrolyte for next-generation energy storage technology.