Preparation of CMS/TiO₂ hybrid material electrorheological fluid and its properties

A new type of organic-inorganic hybrid material, made of carboxyl methyl starch and titanium dioxide, is synthesized by means of modified in-situ sol-gel technique. The IR analysis shows that there is somewhat weak interaction between these two components, whose dispersion is almost up to a molecular level. A series of physical properties of suspension of this hybrid in methyl silicone oil are investigated under direct current field. The mechanic performance of this hybrid electrorheological fluid (ERF) is much stronger than that of pure starch, titanium oxide and their blends ERF. For example, the static shear stress is above 4 kPa and the shear rate is 5 s^-1, when the direct current field of 4 kV/mm DC is applied at room temperature. In the meanwhile, the temperature effect is optimized; its maximum stress appears at around 70°C, and a considerable value remains at even 90°C. In addition, by adjusting the displacement ratio of carboxyl in starch, its suspension stability can be much improved.