The effect of polyvinylpyrrolidone modified nano-polymers on rheological properties of silicon-based shear thickening fluid

Graphene oxide and carbon nanotubes have wide application prospects in many fields due to their unique micro-morphology. In this work, the surface of graphene oxide and carbon nanotubes was simply modified by polyvinylpyrrolidone to graft them together to form a composite cluster which was called GCP. A new shear thickening fluid (GCP/SiO2-STF) was developed by dispersing GCP-composite clusters and nano-silica particles into polyethylene glycol (PEG200). It is found that compared with SiO2-STF, GCP/SiO2-STF can exhibit better shear thickening behavior due to the complex spatial structure and viscous surface of GCP-composite cluster. The relationship between graphene oxide, carbon nanotubes, polyethylpyrroxanone, and nano-silica was analyzed by scanning electron microscopy, and the thickening behavior of GCP/SiO2-STF was explained. The influence of the mass ratio of graphene oxide to carbon nanotubes on the rheological properties of GCP/SiO2-STF was studied by steady-state rheological tests. When the mass ratio of graphene oxide to carbon nanotubes was 0.3, the peak viscosity of GCP/SiO2-STF3 was 468.55 Pa⋅s, which was 116.51% higher than that of SiO2-STF. Second, temperature and plate spacing can significantly change the rheological parameters of GCP/SiO2-STF3. The test results are of great significance for controlling the thickening behavior of STF in order to adapt to complex conditions. In addition, the oscillatory shear test results show that GCP/SiO2-STF3 has excellent energy dissipation performance in different stages. More importantly, this work could find its use for GCP/SiO2-STF in a variety of engineering applications, such as body armor, shock absorption devices, and sports equipment.