The theoretical study of mechanical property and thermostability analysis of poly(vinyl alcohol)/graphene oxide nanofiber composites with different architecture: Molecular dynamics simulation

In order to get a deep insight into the correlation between the structure and properties of composite materials, the models of polyvinyl alcohol (PVA)/graphene oxide nanofiber (GOF) composites with different architecture (including random dispersion of GOF in the composites (referred as R-PVA/GOF composite); columnar cladding of GOF (referred as C-PVA/GOF composite) and 3D core-shell structure of GOF (referred as 3D-PVA/GOF composite) were built, and the mechanical property and thermostability of these composites were analyzed by the molecular dynamic (MD) simulations. It was found that the morphology of GOF in composites had significant influence on its properties. The glass transition temperature (T-g) of C-PVA/GOF composite was the largest compared to those of other materials (3D-PVA/GOF composite; R-PVA/GOF composite and pure PVA). Moreover, the modulus and tensile yield strength of these materials were ordered as follows: C-PVA/GOF > 3D-PVA/GOF > R-PVA/GOF > PVA. The microstructure analysis of materials revealed that the different morphology of GOF affected not only its interactions with PVA but also the ability of components to form hydrogen bonds, the arrangement of PVA molecular chains and the fraction of the free volume in the system, leading to differences in the properties of composites with different structures.