Highly anisotropic conductivity of tablets pressed from polyaniline-montmorillonite nanocomposite

Polyaniline-montmorillonite nanocomposite was prepared from anilinium sulfate (precursor) and ammonium peroxodisulfate (oxidizing agent) using simple one-step method. The resulting nanocomposite obtained in powder form has been pressed into tablets using various compression pressures (28-400 MPa). Electrical conductivities of tablets in two perpendicular directions, i.e. direction parallel with the main surface of tablet (sigma=) and in orthogonal direction (sigma(sic)), and corresponding anisotropy factors (i.e., the ratio sigma=/sigma(sic)) have been studied in dependence on compression pressure used during the preparation. Polyaniline-montmorillonite nanocomposite was characterized using X-ray diffraction analysis, raman spectroscopy, transmission electron microscopy, thermogravimetric analysis and molecular modeling which led to the understanding of the internal structure. Measurement of hardness performed on pressed tablets has been also involved. Taking into account the highest value of anisotropy factor reached (sigma=/sigma(sic)= 490), present study shows a chance to design conductors with nearly two-dimensional conductivity. (C) 2015 Elsevier Ltd. All rights reserved.