ELECTRICAL CONDUCTIVITY AND STABILITY OF GRAPHENE-EMBEDDED POLYMER FILMS

Abstract

Flexible and wearable electronics Flexible electronics Graphene-based polymer composites have received significant interest in the field of flexible electronics and wearables because of their mechanical and electrical flexibility. In this work, electrically conductive and stable composite films were produced through encasing graphene nanoplatelets within poly(vinyl alcohol) (PVA) by an easy and straightforward solution casting method. The structural, electrical, thermal, and mechanical stability of the composite films were studied in terms of the effect of graphene loading. The X-ray diffraction and scanning electron microscopy experimental data supported the evenly dispersed and efficient exfoliation of graphene in the PVA matrix and the Fourier-transform infrared spectroscopy was in support of the high interfacial interaction of the graphene and PVA through hydrogen bonding. The electric conductivity measurements exhibited strong percolation behavior with a steep rise in electric conductivity at around 0.5 wt% graphene loading. At a 1.0 wt. graphene concentration, the composite films showed a several times higher electrical conductivity than when using pure PVA. The thermogravimetric analysis revealed a great enhancement in the thermal stability whereby the degradation onset temperature increased by 30–40-degree ⁰C on incorporation of graphene. Mechanical and electrical stability testing also demonstrated that the conductive network had a very high level of stability during repeated bending and in aging conditions with very little conductivity degradation. A setting was determined of optimal graphene loading of around 0.6 wt% to offer a compromise between high electrical conductivity, flexibility, transparency, and thermal stability. These findings indicate that the graphene-PVA composite films have the potential to be used in the future as flexible electronics, antistatic materials, and wearable sensors.