A new kind of montmorillonite/titania (MMT/TiO2) composite particles is synthesized by means of sol-gel technique for use in electrorheological (ER) active materials. FT-IR, XRD and SEM measurements show that titania is deposited on the surface of montmorillonite particles as anatase nanocrystallites. The MMT/TiO2 composites are used as ER fluid by dispersing them in silicone oil. It is found that the MMT/TiO2 ER fluid has a notable ER effect under DC electric field. When 3 kV/mm electric field is applied, the static yield stress of typical MMT/22.7 wt%Ti02 ER fluid (cp = 25%) is about 8.3 kPa, which is 4 times of that of pure MMT ER fluid. Furthermore, it is demonstrated that the TiO2 coating content has an important influence on the ER effect.

Key words: MONTMORILLONITE, TITANIUM OXIDE, SOL-GEL PROCESS, FT, IR, XRD, SEM