Polyaniline (PANI) and BaTiO3 composite nanotube with high suspension performance in electrorheological fluid

In this research, one-dimensional polyaniline/barium titanate (PANI/BaTiO3) composite nanotubes with core-shell structure were synthesized by hydrothermal treatment, and the surfaces of the nanocomposites were modified with 3-aminopropyltriethoxysilane. The TGA measurement results showed the thermal stability of this nanocomposite was improved compared with pure polyaniline, indicating the deposition of polyaniline on the surface of BaTiO3 nanotubes, which was confirmed by the characterizations and morphology analyses of SEM, FTIR, and XRD. Furthermore, a new electrorheological (ER) fluid was obtained by dispersal of polyaniline/barium titanate nanotubes in silicone oil by ultrasonic mixing technique. The nanotube-based ER fluid exhibited higher suspension stability than original nanoparticle ER fluid. Only insignificant sedimentation was found in this nanotube suspension even several months later. This fluid showed a notable ER behavior with the electric field affection, which was caused by the microstructure change induced by polarization among nanotubes; these observations were well interpreted by analyses of the flow curve, static yield stress, and dynamic test. The results of this study provide possible ways to synthesize ER fluid with good suspension stability and high ER activity by 1-D nanotubes and would help to investigate the potential application of ER fluid in practical realm of waste water treatment.