A combined experimental and computational study of flexible polyvinyl alcohol (PVA)/graphene oxide (GO) nanocomposite films for superior UV shielding with improved mechanical properties

Abstract

The optical and mechanical properties of PVA (polyvinyl alcohol)/GO (graphene oxide) have been intensively studied for promising applications of GO-related materials in various technical fields. In this study, PVA (polyvinyl alcohol)/GO (graphene oxide) composite films have been fabricated via a simple solution casting process and analytically investigated for the UV shielding applications. The weight percentage (wt%) of GO is varied sequentially from 0% to 2.5% (with an interval of 0.5%) in order to examine their optical and mechanical functionality by tuning the structural and morphological aspects of the films. The synthesized films were scrutinized through typical optical and mechanical characterizations unveiling their promising features, which are in coherence with finite difference time domain (FDTD) simulations. FTIR and UV–visible spectroscopic studies confirm the strong interaction between GO and PVA where the localized electronic states of GO can simultaneously add optical transitions and spin moments to the sp2 nanodomains of GO nanosheets. The formation of intercalated nanolaminate structures, hydrogen-bonding interactions, and tuning the crystalline structure of PVA within the composite films as confirmed by XRD and atomic force microscopy (AFM). The 2.5 wt% GO/PVA film shows excellent improvement in tensile strength by 43.65% compared to the pure PVA while the toughness is enhanced from 54.94 MJ m −3 to 63.14 MJ m −3. This poises a superior UV absorption leveraging with optimal point of tensile strength vs elongation at break compared to other PVA/GO nanocomposite films. Stress-strain response studies show improved mechanical properties, and UV transmission studies designate that they are excellent candidates for UV shielding and authorize their employability in relevant applications.