Influence of solvents on the polarization distribution in PVDF

The authors report on polarization reductions when poled PVDF films are immersed in polar solvents like acetone, propanol, ethanol, and methanol for a few minutes. Also, immersion in nonpolar solvents, like hexane or carbon tetrachloride for some hours results in a small reduction of polarization. The amount of the reduction depends on the dipole moment of the solvent molecules, the length of the influence of the solvent, and the poling parameters. The authors also observe an influence on the remanent polarization if the films have been immersed in a solvent for some minutes before poling. They find inhomogeneous polarization distributions in these films that are different from distributions in untreated films before poling. In the case of a polar solvent pretreatment, the development of polarization profiles with several maxima is observed