A modified interfacial polymerization was used to prepare polyaniline (PANI) nanohybrids. The influence of the synthetic route, amounts of bentonite, and the surfactant on the structure, morphology, and optical properties of the as-synthesized nanocomposite were investigated. These materials were characterized by field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, ultraviolet-visible spectroscopy, thermogravimetric analysis, and rheometer. The results show that PANI could be intercalated into the interlayer of the bentonite. The interlayer space increased from 1.25 to 1.486 nm. Then, the hexadecyl trimethyl ammonium bromide was used to modify the surface of bentonite, which was helpful in hybridizing with PANI for its hydrophobic properties. Both the intercalated and coating structure were found in the bentonite/PANI nanohybrid. The TEM and SEM images verified that the surface of the bentonite plate was coated by PANI nanofibers. In addition, for the study of the electroresponsive behavior, the composite was dispersed in silicone oil, and its electrorheological characteristics were examined via both an optical microscope and a rheometer equipped with a high-voltage power source. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 128: 1304-1312, 2013