Incorporating LiTFSI Filler into (1−x)PVA/xPEG Blends for Multifunctional Optoelectronic and Dielectric Applications

The structure modification of polyvinyl alcohol (PVA) polymer upon blending with polyethylene glycol (PEG) and/or doping with lithium bis(trifluoromethane) sulfonimide (LiTFSI) salt was examined. The minimum direct optical energy gap values of 4.28 and 4.35 eV were achieved in 0.7 PVA-0.3 PEG blended polymers and 0.9 PVA-0.1 PEG/LiTFSI blended polymers. The highest refractive index ( n ) values were achieved in 0.7 PVA-0.3 PEG (2.206) and 0.9 PVA-0.1 PEG/LiTFSI (2.194) blended polymer. The highest nonlinear optical parameter values were recorded in 0.7 PVA-0.3 PEG and 0.9 PVA-0.1 PEG/LiTFSI blended polymers, respectively. All blended polymers demonstrated blue-violet color intensity contingent upon the quantity of PEG in each blend. The maximum dielectric constant values were obtained in the 0.9 PVA-0.1 PEG blended polymer. 0.9 PVA-0.1 PEG/LiTFSI blended polymer possesses the highest energy density value. The greatest AC-conductivity values were achieved in the blends with x = 0.1. The alloying of PVA with PEG and/or the addition of LiTFSI salt affected the ionic conductivity.