Nanoceramic Reinforced SWCNT/PVA Composites for Supercapacitors

Abstract

Here we present mechanical engineered effect of SWCNT nanoceramics on polymer thin films. The composite thin film synthesis with different concentrations of nanoparticles and (functionalized SWCNT) f-SWCNT (yield range 75-80%) in (Polyvinyl Alcohol) PVA matrix was carried out by “Simple Solution Deposition Method”. Characterization was accomplished by FTIR, XRPD, SEM and AFM. FTIR results confirmed the successful functionalization of SWCNT’s with bands appearance at 3213 (-OH), 1788 (-C=O), 1320 (-NOX), −C-H stretch at 2136 cm-1 and 602 cm-1 (-SOX). It has also confirmed the synthesis of f-SWCNT/PVA/MO by appearance of individual peaks of all constituents. Peaks of SWCNT’s and polymer were also confirmed by phase analysis through XRPD analysis which not only confirmed the synthesis of f-SWCNT/PVA/MO composites but also the single phase nano NiO and CuO materials with crystallite sizes, 34.5 and 4.05nm, respectively. SEM and 3-D AFM images showed topographic image of SWCNT’s using tapping mode. Transmittance was controlled by using least concentration of SWCNT and transmittance was measured by using UV-Vis spectrophotometer it was seen that transmittance and absorbance peaks were observed in ultra violet range and it was observed that least concentration of SWCNT give the highest transparency. Same trend was observed in case of metal oxides so the composite with least concentration of SWCNT and MO shows best transparency to be used in transparent super capacitors. UV-Vis DRS (Diffused Reflectance Spectroscopy) revealed band gab between 4.2-4.9 eV for composites which are more suitable for super capacitor application as compared to those of NiO (3.86 eV), CuO (3.07eV) and PVA (6.2eV) separately. Band gap of PVA reduced to 4.8 to 4.7 and 4.5 eV by increasing concentration of NiO and CuO while f-SWCNT’s caused further reduction in band gap to 4.38, 4.30 and 4.20 eV. Dielectric constant, dielectric loss, tan loss and AC-conductivity was evaluated and found that all these parameters could be controlled according to need by varying concentration of MO and SWCNT’s. it was seen that the composites with least concentration of MO shows best current storing ability as in case of CCP 1 value of dielectric constant, dielectric loss, tan loss and ac conductivity was 3.3 x 107, 9.7 x108, 4.5 and 19 Sm-1, respectively and for CNP1 value of dielectric constant, dielectric loss, tan loss and Ac conductivity was 1.7 x 107, 3 x108, 2.5 and 9 Sm-1, respectively. Physical properties of composites anticipate them good potential candidates for supercapacitor applications. The tensile strength of of f-SWCNT/PVA/MO composites got enhanced with SWCNT concentrations whereas toughness got enhanced due to MO concentration. The elasticity of metal oxides was enhanced by presence of PVA from as calculated Young’s modulus of PVA was 71.2 Pa. For simple PVA/CuO values of Young’s modulus were 8.2, 18.9 and 27.2 Pa and were enhanced to 62.4, 22.5 and 57.7 by addition of f-SWCNT’s. Similarly for PVA/NiO values of Young’s modulus were 22.7, 25.7, and 30.9 Pa by addition of f-SWCNT’s enhanced to 28.3, 31.3 59.0 Pa.