Generation of the pores on graphene surface and their reinforcement effects on the thermal and mechanical properties of chitosan-based composites

Surface modification is one of the techniques to alter the properties of the existing materials. However, there are numerous studies using various surface modification methods have been published. In the present study, a very simple, cost-effective, and eco-friendly thermal approach is used to modify the surface of the graphene, as the graphene is considered as a wonder material due to its unique properties and a broad spectrum of applications. After modification, pores are generated on the graphene surface which is investigated through field-emission scanning electron microscopy and high-resolution transmission electron microscopy. Additionally, Fourier-transform infrared spectroscopy, X-ray spectroscopy, Raman spectroscopy, and Brunauer-Emmett-Teller analysis are also conducted to validate the changes. Subsequently, the effects of porous graphene on the properties of chitosan-based composites are studied by reinforcing it into the biodegradable polymer chitosan. Chitosan/graphene composites are synthesized via a solution-casting method. The thermal stability and mechanical properties are accomplished through thermogravimetric analysis and a universal testing machine, respectively. The results indicated that the composite with porous graphene exhibited better thermal properties (∼6% lower weight loss) along with improved (21%) tensile strength, which may be due to the enhanced interfacial interactions between the mesh-like porous graphene and chitosan.