Highly anisotropic conductivity of tablets pressed from polyaniline-montmorillonite nanocomposite

• Published in: Materials research bulletin 2016-03, Vol.75, p.139-143
• Main Authors: Tokarský, Jonáš, Kulhánková, Lenka, Neuwirthová, Lucie, Mamulová Kutláková, Kateřina, Vallová, Silvie, Stýskala, Vítězslav, Čapková, Pavla
• Format: Article
• Language: English
• Subjects: A. Composites; A. Layered compounds; ANISOTROPY; B. Chemical synthesis; C. High pressure; CLATHRATES; COMPRESSION; COMPUTERIZED SIMULATION; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; D. Electrical properties; ELECTRIC CONDUCTIVITY; HARDNESS; MATERIALS SCIENCE; MONTMORILLONITE; NANOCOMPOSITES; ORGANIC POLYMERS; POWDERS; RAMAN SPECTROSCOPY; SULFATES; SURFACES; THERMAL GRAVIMETRIC ANALYSIS; TRANSMISSION ELECTRON MICROSCOPY; TWO-DIMENSIONAL SYSTEMS; X-RAY DIFFRACTION
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2015.11.041

[Display omitted] •Montmorillonite (MMT) can be intercalated with polyaniline (PANI) chains.•Tablets pressed from PANI/MMT exhibit high anisotropy in electrical conductivity.•Pressure 28MPa is sufficient to reach the anisotropy.•Tablets pressed from pure PANI also exhibit anisotropy in electrical conductivity. 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 (28–400MPa). Electrical conductivities of tablets in two perpendicular directions, i.e. direction parallel with the main surface of tablet (σ=) and in orthogonal direction (σ⊥), and corresponding anisotropy factors (i.e., the ratio σ=/σ⊥) 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 (σ=/σ⊥=490), present study shows a chance to design conductors with nearly two-dimensional conductivity.