Rheology of (+/-)-camphor-10-sulfonic acid doped polyaniline-m-cresol conducting gel nanocomposites

The rheological behavior of polyaniline-(+/- charriphor-10-sulfonic acid)(0.5)m-cresol [PANI-CSA(0.5)-m-cresol] gel nanocomposites (GNCs) with Na-montmorillonite clay (intercalated tactoids) is studied. The shear viscosity exhibits Newtonian behavior for low shear rate (<2 X 10(-4) s(-1)) and power law variation for higher shear rate. The zero shear viscosity (eta(0)) and the characteristic time (2) increase but the power law index (n) decrease with increase in clay concentration. In the GNCs storage modulus (G') and loss modulus (G) are invariant with frequency in contrast to the pure gel. The G' and G' exhibit the gel behavior of the GNCs up to 105 degrees C in contrast to the melting for the pure gel at 75.7 degrees C. The percent increase of G' of GNCs increases dramatically (619% in GNC-5) with increasing clay concentration. The conductivity values are 10.5, 5.65, 5.51, and 4.75 S/cm for pure gel, GNC-1, GNC-3, and GNC-5, respectively, promising their possible use in soft sensing devices. (C) 2007 Wiley Periodicals, Inc.