Is Chitosan the Promising Candidate for Filler in Nature-Friendly Electrorheological Fluids?
N. M. Kuznetsov, Yu. D. Zagoskin, Artem V. Bakirov, A. Yu. Vdovichenko, С. Н. Малахов, A.P. Istomina, С. Н. Чвалун
Abstract
In this study, an electrorheological effect of the suspensions containing porous chitosan particles in olive oil in a wide range of electric fields is reported. Porous chitosan particles were produced by freeze-drying. The structure of the filler was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray scattering. Electrorheological behavior of low-filled fluids (0.1, 0.2, 0.5, and 1.0 wt %) was studied in shear and oscillation modes. Rheological data were fitted by Bingham, Cho–Choi–Jhon, and Seo–Seo models. Conductivity measurements were carried out to characterize the electrophysical properties of studied fluids. Polarization processes were considered from the standpoint of the Cole–Cole equation. Natural biodegradable materials such as chitosan and olive oil were used as components. The fluids showed high response to electric field and stable cyclic operation in on/off mode at extremely low concentrations. The yield stress reaches about 100 Pa for a 1 wt % suspension under an electric field of just 1 kV/mm. The sedimentation stability of the samples dramatically increases when the percolation threshold is passed. The sedimentation ratio at 1 wt % of the filler content remains at the level of 90% after almost a month. Thus, suspensions were considered as an alternative to typical silicon oil-based electrorheological fluids.