Preparation and electrorheological property of rare earth modified amorphous BaxSr1−xTiO3 gel electrorheological fluid

Preparation and electrorheological properties of triethanolamine-modified TiO2

“…Generally, the mechanism treats particle polarization by using complex dielectric constant, e ¼ e 0 2ie 00 , where the real part e 0 is related to polarizability and the imaginary part e 00 is related to the dielectric loss, and can be expressed as s=2pf , where s is the conductivity and f is frequency of the external electric field. This theory is supported by recent experiments on mesoporous ceriumdoped TiO 2 [6], and amorphous Ba x Sr 1-x TiO 3 [16]. However, there is no dielectric relaxation peak in triethanolamine-modified TiO 2 shown in Fig.…”

Comment on “Preparation and electrorheological property of rare earth modified amorphous BaxSr1−xTiO3 gel electrorheological fluid”

“…6 in Ref. [1], which provides the shear yield stress as a function of an applied electric field strength at a relatively low shear rate, drew our attention. We reanalyzed their ER data, via both the polarization model and the conductivity model, and found that the yield stress is strongly affected by the volume fraction of the solid particles.…”

“…Wu et al [1] reported a newly developed rare earth modified amorphous barium strontium titanate gel based ER fluid exhibiting higher yield stress, up to 14.9 kPA, with a low leaking of current density at the electric field strength of 3.5 kV/mm. They explained that sufficiently active polar groups, such as the hydroxyl groups, on the surface of gels promote surface activity by producing a synergic effect or could polymerize with each other, and their ER activity is dominated mainly by Wagner interfacial polarization.…”