Study on the effect of silanization and improvement in the tensile behavior of graphene-chitosan-composite

In the present study, silane-functionalized graphene (f-graphene)-reinforced chitosan nanocomposite films exhibiting enhanced mechanical properties have been prepared by the solution casting method. These nanocomposite films were characterized by X-ray diffraction, Raman spectroscopy and thermogravimetric analysis. In order to investigate the effect of silane functionalization, tensile tests were performed on original, oxidized and silane-functionalized graphene-reinforced chitosan nanocomposite films. Tensile results show that silane functionalization groups offer a substantial increase in the interfacial adhesion between filler and host matrix. This result is also confirmed by the surface morphology of the fracture surface in scanning electron microscope analysis. Qualitative analysis using Raman and Fourier transform infrared spectroscopy revealed the existence of Si-O-Si and Si-O-C bonds in the silanized composite. Thermal analysis of the samples shows that the material is stable up till 250 °C and maintains its thermal stability all throughout the process until it starts degrading after 510 °C. Atomic force microscopy reveals that the material is well exfoliated after the oxidation of graphene and also displays the existence of 3-6 layers of exfoliated graphene sheets. X-ray photoelectron spectroscopy studies also reveal the existence of silicon in the single state and quantify the sample to be approximately around 4% (±0.5%) of the total atomic weight.