Fabrication of self-assembled polyaniline tubes and their electrorheological characteristics

Polyaniline (PANI) nanotube (NT) particles possessing a rectangular shape were fabricated by self-assembly via a chemical soft template technique with citric acid as the dopant acid at an organic dopant acid to aniline monomer molar ratio of 1: 4. Morphology of the PANI NTs was examined by scanning electron microscope and transmission electron microscope, while their chemical structure was tested by FT-IR spectroscopy and X-ray diffraction. PANI NTs were suspended in silicone oil for electrorheological (ER) characterization, and their fibrillation phenomenon under an induced electric field caused by their highly polarizable characteristics was observed directly by an optical microscope. Their rheological behaviors under different electric fields were tested using a rotational rheometer, exhibiting increased ER effects with an input electrical field strength. Frequency dependence of the dielectric spectra was also obtained using a LCR meter and well related with the ER effect.