Study of the Electronic Properties of Solid Polymer Electrolytes Based on Blends of CMC, PEO, and Acetic Acid

Abstract

The effect of blending on the electronic properties of sodium carboxymethyl cellulose (CMC) and polyethylene oxide (PEO) was studied theoretically using density functional theory (DFT). The CMC and PEO structures were first optimized individually, then were optimized at different blending ratios. All calculations were carried out at the B3LYB/3-21g* level of theory. The changes that occurred in the electronic properties of the individual polymers due to blending were presented in terms of total dipole moment (TDM), the electronic bandgap energy (HOMO/LUMO band gap), and molecular electrostatic potential (MESP). The results indicated that the blended structures were suitable for application in electrochemical devices as the TDM increased, HOMO/LUMO bandgap decreased, and electro-negativity increased. Also, it was concluded that the blended structures' electronic properties were also enhanced by the addition of small concentrations of acetic acid.