GO based PVA nanocomposites: tailoring of optical and structural properties of PVA with low percentage of GO nanofillers

Abstract

Graphene-based polymer composites are gaining interest as a modish class of substance that holds promising angles on diverse applications. In this work, Graphene Oxide (GO) based Polyvinyl Alcohol (PVA) nanocomposites (PVA-GO) have been prepared by employing a facile solution casting method. Low concentrations of GO nanofiller (0.25%, 0.50%, 0.75%, and 1.0%) were used and the result of the use of them over the distinct substantial characteristics of the nanocomposites was evaluated. The different features of the as-synthesized nanocomposites such as optical, structural, chemical, and thermal properties were identified by UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), and Thermo-gravimetric analysis (TGA), respectively. From the structural analysis of the crystallinity of the nanocomposite it is evident that a reduction in crystallinity caused by the amalgamation of the GO nanofiller. FTIR study shows improved interaction between the GO nanofiller and PVA matrix. The incorporation of GO was found to reduce the optical band gap of the nanocomposite both for the direct and indirect transition. The Urbach energy of the nanocomposite increases with the increase of the GO concentration suggests the formation of localized states causing a reduction in the optical band gap. PVA-GO nanocomposites with improved and tunable physical properties synthesized from a simple and economic route may pave a new horizon for polymer-based optoelectronic devices.

Optimization of the glass transition temperature of polyvinyl pyrrolidone/polyacrylamide blend films using response surface methodology

“…Hence, this feature is crucial in determining the optical applicability of the understudied materials. The optical absorption of materials with thickness t is related to its absorption coefficient α by the relation α ( λ ) = 2.303 ( A / t ) 54–56 . Using this relation, the absorption coefficient values of the PVP, PAM, and optimized blended films were computed and the determined α values are plotted as shown in Figure 7b.…”

“…The indirect E g of the PVP, PAM and optimized blended films are 5.11, 4.94, and 4.9 eV, respectively. The E g (direct E gd and indirect E gi ) of the samples was determined using Tauc's relation (i.e., ( ahv ) n = A( hv − E g ), A = constant, hv = photon energy, and n = 2 and ½ for direct and indirect electronic transitions) 53,54,57 . For determining the optical energy band gap, the ( αhν ) 2 and ( αhν ) 0.5 values were plotted against the incident photons energy as shown in Figure 7c,d, respectively, and the extrapolated linear parts of the plotted curves to meet hν = 0 represent the optical energy band gap values.…”

“…The absorption coefficient α of materials, which is associated with the electronic transition due to photon irradiation, indicates the portion of light absorbed per its thickness and is vital in determining the E g and Urbach energies (E U ) of materials. 53,54 Hence, this feature is crucial in determining the optical applicability of the understudied materials. The optical absorption of materials with thickness t is related to its absorption coefficient α by the relation α(λ) = 2.303 (A/t).…”

“…The optical absorption of materials with thickness t is related to its absorption coefficient α by the relation α(λ) = 2.303 (A/t). [54][55][56] Using this relation, the absorption coefficient values of the PVP, PAM, and optimized blended films were computed and the determined α values are plotted as shown in Figure 7b. In the visible-near infrared spectra region, it is evident that the parental polymers have relatively poor Additionally, the optical energy band gap of PVP, PAM, and the optimized blended films was determined and tabulated in Table 5.…”

Influence of graphene oxide on rheology, mechanical, dielectric, and triboelectric properties of poly(vinyl alcohol) nanocomposite hydrogels prepared via a facile one step process

“…The dielectric properties of the PVA/GO nanocomposite hydrogels suggest the ability of the material to store electrical charge, and these properties depend on the atomic, ionic, electronic, interfacial, and dipolar polarization under the influence of an externally applied electric field. [65][66][67] In this regard, nanocomposite hydrogels possessing these properties could be useful for energy storage devices and electronics applications. 54 The dielectric properties of the PVA/GO nanocomposite hydrogels with increased concentration of GO as a function of frequency were measured at room temperature (Table S3, ESI †).…”