High electrical anisotropy in hydrochloric acid doped polyaniline/phyllosilicate nanocomposites: Effect of phyllosilicate matrix, synthesis pathway and pressure

Pressed tablets from polyaniline/phyllosilicate nanocomposites have been prepared under various conditions in order to optimize anisotropic conductivity of composite by ordering of flat phyllosilicate particles intercalated with polyaniline (PANI). Powder samples of PANI/phyllosilicate nanocomposites have been prepared using two phyllosilicates, montmorillonite and vermiculite, with a different layer charge. Two precursors were used, anilinium hydrochloride and anilinium sulfate. Prepared PANI/phyllosilicate composites were subsequently doped by hydrochloric acid via rinsing after polymerization process and for the DC conductivity measurements pressed into tablets. Applied pressure was 28 MPa and 128 MPa. Highly anisotropic conductivity has been achieved in pressed tablets. The in-plane conductivity for PANI/montmorillonite was 0.084 S/cm, i.e., 1000 × higher than in the direction perpendicular to the tablet plane. Increase of pressure up to 128 MPa led to dramatic decrease of conductivity.