Porous TiO2 Nanoparticles Derived from Titanium Metal–Organic Framework and Its Improved Electrorheological Performance

A simple method for synthesis of porous TiO2 nanoparticles was developed via a two-step route using titanium metal–organic framework (MOF) as a precursor, in which MOFs were first prepared by a cetyltrimethylammonium bromide (CTAB) assisted solvothermal method and then calcined in air at 500 °C. After pyrolysis of precursor MOFs, the anatase TiO2 inherited the porosity of precursor MOF and possessed a large surface area and uniform pore distribution, which was subsequently adopted as an electrorheological (ER) material by dispersing in silicone oil. ER activities of MOFs and porous TiO2 based suspensions under the applied electric fields were investigated in a controlled shear rate (CSR) mode. In contrast to MOFs based ER fluids, the suspension of porous TiO2 exhibited a higher ER efficiency and lower leakage current. Furthermore, the improvement of dielectric properties was found to be responsible for the enhanced ER activity through an investigation of dielectric spectrum.