The evolution of the thermodynamic property of graphene oxide nanofiber coated poly(vinyl alcohol) resin surface by the molecular dynamic simulations

Abstract

A series of 3D models of graphene oxide (GO) nanofibers coated poly(vinyl alcohol) (PVA) composites (GO-C-PVA) were structured and their thermodynamic properties were studied by the molecular dynamic (MD) simulations. The results showed that the mechanical properties of GO-C-PVA were much stronger than those of pure PVA and PVA composites with random dispersion of GO. GO nanofibers coated around PVA also increased the glass transition temperature (Tg) of composite and improved its crystallization properties. Moreover, the mechanical properties and Tg of GO-C-PVA were increased with the increase of aspect ration and concentration of GO nanofibers. The maximum Young's modulus, shear and bulk modulus of composite with 10:3 aspect ration and 38.7% GO nanofibers was increased about 10, 8 and 15 times compared with that of pure PVA, respectively. Its yield strength was also increased by 10 times while maintaining excellent stretchability. Its Tg was up to 397.85 °C. The microstructure analyses of materials revealed that GO nanofibers not only interacted strongly with PVA, but also induced PVA crystallization and decrease the free volume of composite, thereby restrained the moving of PVA. Which result in the improvement of the thermodynamic properties of GO-C-PVA combined with the excellent properties of GO itself.