Stress Behavior and Conductivity of the Electro- Rheological Suspensions

Abstract

The steady stress under static electric fields and the conduction current passing through the electro-rheological (ER) suspensions with cation exchange resin particles were investigated simultaneously as a function of the shear rate. The shear thinning behavior was found for a suspension with a higher viscosity of the continuous phase. Further, a remarkable dip behavior was found for a dilute ER suspension. The apparent conductivity, which was calculated from the conduction current, probed sensitively the corresponding behavior to the stress responses.

Simultaneous observations of microgap flow behavior and microstructure of electro-rheological nano-suspensions based on titanium dioxide nano-particles

“…5. Such behavior of the shear thinning-like behavior (or dip behavior) in the ER effect was also reported for the ER micro-suspension [36][37][38]. Furthermore, significant hysteresis, especially at higher strengths of the electric field can be seen in Fig.…”

Electrically Induced Microstructures in Micro- and Nano-Suspensions and Related Physical Properties

“…Further, a remarkable dip behavior was found for suspensions of 5 and 10 wt %: The stress decreased with an increase in the shear rate, keeping 'ðEÞ > 'ð0Þ, and it gradually increased again and approached the stress under no electric fields. [99][100][101] Behavior similar to the dip behavior (or shear thinning) was often reported for other suspensions. 102,103 The dip behavior was sensitively probed by the apparent conductivity, which was measured simultaneously with stress.…”

“…102,103 The dip behavior was sensitively probed by the apparent conductivity, which was measured simultaneously with stress. [99][100][101] The apparent conductivity also showed a steep decrease above M n $ 10 À2 for the suspensions of 5 and 10 wt %. Interestingly, the apparent conductivity for the suspension of 5 wt % showed not only a local minimum around M n $ 10 À1 but also a local maximum after the minimum, the local maximum of which was not observed 100 in the stress scaled by 2" c " 0 ðEÞ 2 .…”

“…[99][100][101] For M n > 0:3, the shear thinning was found for a suspension with a particle concentration of 30 wt % (0 ¼ 0:33), 101 the particles of which were suspended in a silicone oil with higher viscosity c . Further, a remarkable dip behavior was found for suspensions of 5 and 10 wt %: The stress decreased with an increase in the shear rate, keeping 'ðEÞ > 'ð0Þ, and it gradually increased again and approached the stress under no electric fields.…”