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In the present study, we report the fabrication and characterizations of flexible dielectric nanocomposites consisting of water soluble polypyrrole (WPPy)/polyvinyl alcohol (PVA)/graphene oxide (GO) at different GO loadings (0.5 -3 wt %). The WPPy/PVA/GO nanocomposites were characterized using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV-vis spectroscopy (UV), X-ray diffraction (XRD), thermogravimetric analysis (TGA), polarized optical microscopy (POM), Scanning electron microscopy (SEM) and atomic force microscopy (AFM). FTIR studies indicate the strong chemical interaction between GO and polymer systems. SEM results confirm that GO was homogeneously dispersed within the polymer matrix. The nanocomposites exhibit significant enhancement in the dielectric constant with low dielectric loss values as a function of GO loading which resulted from the fine dispersion of GO in the polymer matrix. The dielectric constant increases from (ε = 27.93, 50 Hz, 150 o C) for WPPy/PVA (50/50) blend to (ε = 155.18, 50 Hz, 150 o C) for nanocomposites with 3 wt % GO loading and the dielectric loss increases from (tan δ = 2.01, 50 Hz, 150 o C) for WPPy/PVA (50/50) blend to (tan δ = 4.71, 50 Hz, 150 o C) for nanocomposites with 3 wt % GO loading. Thus, these high-k WPPy/PVA/GO nanocomposites are potential flexible high-performance dielectric materials for electronic devices such as highfrequency capacitors or embedded capacitors.

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Polyvinyl alcohol (PVA)/potassium chromate (K 2 CrO 4 ) composite films were prepared by solution casting technique using distilled water as a solvent and further investigated using Fourier transform infrared spectroscopy (FTIR), UV-visible spectroscopy X-ray diffraction (XRD), thermogravimetric analysis (TGA), optical microscopy, scanning electron microscopy (SEM) and dielectric measurements. Microscopic studies reveal that K2CrO4 was homogenously mixed with PVA matrix due to interfacial interaction between PVA and K2CrO4. The composite films show very high dielectric constant and relatively low dielectric loss. Hence, such composite materials with improved dielectric properties can be useful for fabrication of electrical charge storage device.

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