Filler Dependent Microstructural and Optical Properties of PVDF/PEG Blends Versus PVDF/GO Nanocomposites

Abstract

The micro-structural features and the optical properties of polymer blends (PB) of polyvinylidene fluoride (PVDF) base with polyethylene glycol (PEG) and polymer nanocomposites (PNC) of PVDF base with graphene oxide (GO) as fillers are compared. Different weight fractions of PVDF/PEG and PVDF/GO samples were prepared through solution casting followed by spin coating. The microstructure of PVDF/PEG and PVDF/GO shows formation of immiscible/compatible/ homogenous microstructures over different extents of loading of the filler components. UV-Visible spectrometry revealed an increase in absorbance with the amount of filler and the absorbance was found to be lesser and highly dispersive for the PB as compared to PNC, attributed to the heterogeneity/electrical conductivity of the respective fillers of the two systems. Spectroscopic ellipsometry was used to study the various optical constants (e.g. refractive index, extinction co-efficient, etc.) & their dispersion behavior over the visible range of wavelengths. The parameters show large variation as a function of component fillers due to the different extent of interaction of matrix/filler. The optimized parameters were obtained for the 20% PB & the 5% PNC samples respectively, suggesting PNC with nano fillers are always to be a better choice for developing them as materials suitable for various optical applications.