Electrorheological Properties of Phosphoric Ester Cellulose Electrorheological Suspensions at Elevated Temperatures

Abstract

The electrorheological (ER) behavior of suspensions in silicone oil of phosphoric ester cellulose powder (average particle size: 17.77 µm was investigated at elevated temperatures up to 100°C. For development of anhydrous ER suspensions for use at wide temperature range, the effect of temperature on ER activity has studied. Anhydrous ER suspensions were mixed with the phosphoric ester cellulose particles made from the phosphoric ester reactions of cellulose. Durjng increasjng temperature, not only analysis of electrical properties, such as dielectric constant, current density and electrical conductivity but also rheological properties of ER suspensions were studied. Current density, conductivity and electrorheological effect (rA/7: 0) of phosphoric ester cellulose ER suspensions showed law dependence on temperature. Shear stress was closely related to the square of dielectric constant mismatch parameter (/3 2) under constant shear rate and electric field.

Electrorheological Properties of Phosphoric Ester Cellulose Electrorheological Suspensions with Activation of Dispersed Particles

“…The particles were dried in a vacuum at 100 • C oven for 48 h. Particle size distribution measured by Image Analyzer System (Model Omnimet 2, UK) and mean particle size was 17.77 µm. 18 Phosphoric ester cellulose particles dispersed into silicone oil were stable below 200 • C proving that ER suspensions based on phosphoric ester cellulose were anhydrous. 15,18 During activation at 120 • C, the density of dispersed solid particles was measured every activating hour.…”

“…18 Phosphoric ester cellulose particles dispersed into silicone oil were stable below 200 • C proving that ER suspensions based on phosphoric ester cellulose were anhydrous. 15,18 During activation at 120 • C, the density of dispersed solid particles was measured every activating hour. Initial density and volume fraction of dispersed ER particles, 1.31 ± 0.05 g cm −3 and 20%, were hardly changed during the activation.…”

Temperature-dependent electrorheology of a suspension based on copolymeric P(NIPAM-co-[AMIm]Cl) colloidal particles

“…While for the unhydrous ER materials, ER effect will increase with temperature because of the similar trend in dielectric properties (i.e. dielectric constant of the ER fluid) [41]. For the polymers with low glass transition temperatures, the temperature effect on ER performance might be more complex.…”