Enhanced dielectric and electrorheological properties of needle-like TiO2/polyrhodanine core/shell hybrid nanostructure

In this study, antisedimentation, dielectric, electrorheological (ER) and creep-recovery properties of needle-like TiO2/polyrhodanine (PRh) nanocomposite were investigated. Antisedimentation ratio of needle-like TiO2/PRh was determined to be 45% after 30 days in silicone oil (SO). Polarizability and relaxation time of needle-like TiO2/PRh/SO system were determined to be 0.18 and 2.9 X 10(-5) s, respectively by the dielectric spectroscopy which was further used to evaluate the ER performance of the dispersion, and the data obtained were in good agreement with the overall ER results. ER properties of needle-like TiO2/PRh/SO system were determined by taking the effects of shear rate, shear stress, electric field strength, and temperature into account using a torque electrorheometer. Non-Newtonian shear thinning behaviors were observed for the samples. Vibration damping capabilities of the dispersions were investigated by measuring their elastic and viscous moduli as functions of frequency, time, and electric field strengths. Enhanced and reversible viscoelastic deformations were recorded for needle-like TiO2/SO system from creep-recovery tests with 88% recovery under E = 53.5 kV mm(-1) condition; thus, the system was classified as a smart one and suitable for potential vibration damping applications. (c) 2015 Wiley Periodicals, Inc.