Application of electro-rheological effect for functional materials

摘要

Electro-rheological (ER) fluids which show a change in viscous properties quickly and reversibly under an electric field have been applied in various fields. In this study, in another potential application, the ER effect was examined in the fabrication of a new functional material. Microcrystalline cellulose particles with high dielectric properties were dispersed in two types of silicone rubber/silicone oil mixtures. The influence of particle content, type and intensity of electric field and other factors on the ER effect was investigated for the fluids before curing. The suspensions were cured under electric fields (AC/DC) at 100°C, and then the dielectric properties (dielectric constant and dielectric loss factor) under compressive strain were measured for the cured materials. It was found that the ER effect of the suspensions employed here increases with an increase of particle content and intensity of electric field only under an AC field, and that the dielectric properties of the cured materials under an AC field increase, which may be due to the oriented particle structure. These dielectric properties increase monotonously with increasing compressive strain, and a higher ER effect material shows higher dielectric property changes. All materials prepared and measured in this study show hysteresis behavior for dielectric properties under compressive strain.