반전도성 polyaniline의 유도체들로서 poly(aniline-co-sodium diphenylamine sulfonate), poly(aniline-co-o-ethoxyaniline), poly(o-methylaniline), poly(o-methoxyaniline)를 중합하여 전기유변유체의 입자로 사용하였다. 각 분산액은 전기장하에서 전형적인 전기유변특성을 나타냈으나, 낮은 전단변형률에서의 stress plateau 영역에서 입자의 종류에 따라 다른 흐름특성을 얻었다. 전기유변유체의 전기장에 따른 flow curve 변화와. dynamic yield stress와 전기장 간의 관계로부터 접근한 scaling law를 이용하여 각 전기유변유체의 universal flow curve를 구하였다.
Semiconductive polyaniline and its derivatives such as poly(aniline-co-sodium diphenylamine sulfonate), poly (aniline-co-o-ethoxyaniline), poly (o-methylaniline), and poly (o-methoxyaniline) were synthesized, and then adopted as suspending particles of the electrorheological (ER) fluids. All suspensions of these polyaniline derivatives showed typical ER properties under high applied electric fields. However, flow behaviors are observed to be quite different depending on the polyaniline derivatives, especially in the stress plateau regions obtained at low shear rates. Using a scaling law, we also obtained universal cures of ER fluids from the flow curves at each applied electric field based on the relationship between the dynamic yield stress with the applied electric field and flow curve changes according to the electric fields.
