Graphene oxide-polyacrylamide composites: Optical and mechanical characterizations

Abstract

Graphene oxide (GO) is a two-dimensional carbon material with similar one-atom thickness, and is a light material having extremely high strength and thermal stability [1]. Thus, GO is an efficient filler for the enhancement of the electrical, mechanical, and thermal properties of composite materials [2]. We focused on GO as a nanofiller in polyacrylamide hydrogels and GO-PAAm composites to investigate the optical and mechanical properties of the composites in this chapter. Gelation, fractal analysis, and optical energy band gap measurements of the composites were performed by UV-Vis and fluorescence spectroscopy techniques. The sol-gel phase transition and its universality were monitored and tested as a function of GO contents. The geometrical distribution of GO during gelation was presented by the fractal analysis. The fractal dimension of the composite gels was estimated based on the power law exponent values using scaling models. UV-Vis spectroscopy was used to investigate the behavior of optical band gap of GO-PAAm composites. On the other hand, mechanical measurements were employed to determine toughness and compressive modulus of the polymer composites before and after swelling. The behavior of compressive modulus was explained by the theory of rubber elasticity. © 2019 John Wiley & Sons, Inc. All rights reserved.