Characterization of ZN2+-Doped Poly(Vinylidene Difluoride) Films by X-Ray Photoelectron Spectroscopy
Thin films of fluorophores coated onto poly(vinylidene difluoride) (PVDF) substrates are reported to have enhanced photophysical properties. Zinc (II) has proven to be an effective dopant in these polymer films by further increasing the photophysical observations of the surface dye. These enhancements make for effective sensors when exposed to various analytes. Some studies of interfacial effects between the top atomic layer of these doped PVDF films and sensing dye layer have been investigated by focusing on absorbance and fluorescence spectroscopy of the dye, which lead to how the orientation of these dyes change from being a component of this bilayer. The focus has been primarily on understanding the dye component, then drawing conclusions on how the top PVDF layer may have led to these effects on these dyes. Instead, this thesis centers solely on understanding the chemical composition of the top 10 nm of these PVDF films and extrapolating how these findings may affect the phenomenon seen in the photophysical layer. With the use of X-ray photoelectron spectroscopy (XPS), elemental analysis has shown there is no additional coordination besides what had been previously reported of a tetragonally distorted six-coordinate Zn2+ complex with N,N-dimethylformamide (DMF) ligands. Signature pinhole formation has also been observed. Surface roughness profiles prove there is no change in surface roughness with an increase of Zn2+ doping. All lead to the conclusion that the only contributing factor in these doped PVDF films is the introduction of surface charging that suppresses aggregation and increases monomer formation of these dyes.
"Characterization of ZN2+-Doped Poly(Vinylidene Difluoride) Films by X-Ray Photoelectron Spectroscopy"
Dissertations and Master's Theses (Campus Access).