Cover Image

Effect on Poly(C6H5NH2) Emeraldine Salt by FeCl3 and KMnO4 as Secondary Dopants

Kedir Mamma, Khalid Siraj, Nathan Meka


Polyaniline in its emeraldine salt form was synthesized by chemical method from aniline monomer in the presence of HCl mixed with LiCl and Ammonium-persulphate (APS) as oxidant. Then a portion of samples was de-doped with NH3 solution and another equal portion was separately post doped with secondary dopants such as FeCl3 and KMnO4 respectively. Finally the dried samples of polyaniline prepared in all its three different forms were characterized by ultraviolet – visible (UV-Vis) spectroscopy, Fourier- Transform Infrared (FTIR) spectroscopy and electrical conductivity measurement. FT-IR and UV-Vis spectra confirmed the expected structural modification upon doping, undoping and post doping processes of the polymer. The influences of secondary doping on the electrical conductivity were also investigated from their spectroscopic data and the dramatic rise in conductivity was said to be induced from the secondary doping is attributed by structural rearrangement from a compact-coil form of PANI to a more expanded conformation. The result also shows that secondary doping increased the  conjugation. Their measured electrical conductivities were from 0.02 for undoped, 156 for primary doped form and increasing from 158 to 210 S/cm for those secondary doped polyaniline.


Secondary dopant, PANI, FT-IR, UV-Visible, Electrical conductivity

Full Text:



Rao PS, Sathyanarayana DN, Jeevananda T. In Advanced Functional Molecules and Polymers, H. S. Nalwa (ed.), Gordon and Breach, Tokyo, 2001, 3:79

Waltman RJ, Bargon J and Diaz AF. Electrochemical studies of some conducting polythiophene films. J Phy Chem. 1983, 87:1459-1463

Jansson R, Arwin H, Bjorklund A, Lunstrom I. Characterization and switching of thin poly-N- methylpyrrole films. Thin Solid Films, 1980, 125: 205-211

Diaz AF, Matninez A, Kanazawa KK, Salmon M. Electrochemistry of some substituted pyrroles. J Electroanal Chem. 1980, 130:181-187

Ohsawa JJ, Kaneto K, Yoshino K. Electrical and Optical Properties of Electrochemically Prepared Polyfuran. Jpn J Appl Phys. 1984, 23:L663-L665

Huang WS, Humphrey BD, MacDiarmid AG. Polyaniline, a novel conducting polymer. Morphology and chemistry of its oxidation and reduction in aqueous electrolytes, J Chem Soc Faraday Trans 1. 1986, 82:2385-2400

Lu FL, Wudl F, Nowak M, Heeger AJ. Phenyl-capped octaaniline (COA): an excellent model for polyaniline, J Am Chem Soc. 1986, 108:8311-8313

Green AG, Woodhead AE. CCXLIII.—Aniline-black and allied compounds. Part I, J Chem Soc Trans. 1910, 97:2388-2403; CXVII.—Aniline-black and allied compounds. Part II, 1912, 101:1117-1123

Athawale AA, Kulkarni MV, Chabukswar VV. Studies on chemically synthesized soluble acrylic acid doped polyaniline, Mat Chem Phys. 2002, 73:106-110

MacDiarmid AG, Chiang JC, Richter AF, Somasiri NLD, Epstein AJ. In Conducting Polymers, L. Alcacer, ed., Reidel Publication, Dordrecht, 1987, 105

Avlyanov JK, Min YG, MacDiarmid AG, and Epstein AJ. Polyaniline – conformational-changes induced in solution by variation of solvent and doping level. Synth Met 1995, 72: 65-71

Min Y, Xia Y, MacDiarmid AG, and Epstein AJ. Vapor phase ‘‘secondary doping’’ of polyaniline. Synth Met. 1995, 69:159-160

Cao Y, Smith P, Heeger AJ. Counter-ion induced processibility of conducting polyaniline and of conducting blends of polyaniline in bulk polymers. Synth Met. 1992, 48:91-97

Rao PS, Sathyanarayana DN, Jeevananda T. In Advanced Functional Molecules and Polymers: Electronic and Photonic Properties, H. S. Nalwa (ed.), Gordon and Breach, Tokyo, 2001, 3: 79-95

MacDiarmid AG Epstein AJ. The concept of secondary doping as applied to polyaniline. Synth. Met. 1994, 65:103-116

Ball IJ, Huang SC, Wolf RA, Shimano JY, Kaner RB. Pervaporation studies with polyaniline membranes and blends. J Mem Sci. 2000, 174:161-176

Jonsson SKM, Birgerson J, Crispin X, et al. The effects of solvents on the morphology and sheet resistance in poly (3, 4-ethylenedioxythiophene)– polystyrenesulfonic acid (PEDOT–PSS) films. Synth Met. 2003, 139:1-10

Bredas JL, Chance RR, Silbey R. Comparative theoretical study of the doping of conjugated polymers: Polarons in polyacetylene and polyparaphenylene. Phys Rev B. 1982, 26:5843-5854

Angelopolos M, Asturias GE, Ermer SP, Scherr EM, MacDiarmid AG, Akhtar M, Kiss Z, Epstein AJ. Polyaniline: Solutions, Films and Oxidation State. Mol Cryst Liq Cryst. 1988, 160:151-163

Epstein AJ, Ginder JM, Zuo F, Biegelow RE, Wou HS, Tanner DB, Fichter AF, Huang WS, MacDiarmid AG. Insulator-to-metal transition in polyaniline. Synth Met. 1987, 18:303-309.

Wei Y, Jang GW, Chan CC, Hsueh KF, Hariharan R, Patel SA, Whitecar CK. Polymerization of aniline and alkyl ring-substituted anilines in the presence of aromatic additives. J Phys Chem. 1990, 94:7716-7721

MacDiarmid AG, Chiang JC, Richter AF, Somarisi NLD. In Conducting Polymers, Special Applications. L. Alcacer (Ed). Reidel, Dordrecht, 1987,105

Mattoso LHC, MacDiarmid AG, Epstein AJ. Controlled synthesis of high molecular weight polyaniline and poly(o-methoxyaniline). Synth Met. 1994, 68:1-11

Heeger AJ. Semiconducting and Metallic Polymers: The Fourth Generation of Polymeric Materials. Angew Chem In. Ed. 2001, 40:2591-2611

Beadle PM, Nicolau YF, Banka E, Rannou P, Djurado D. Controlled polymerization of aniline at sub-zero temperatures. Synth Met.1998, 95:29

Jiang Y, Li D, Xie D, Wu Z, Yang B. Proceedings of SPIE-The International Society for Optical Engineering 2001, 4414:358-361

Nakajima T, Kawagoe T. Polyaniline: Structural analysis and application for battery. Synth Met. 1989, 28:629-638

Watanabe A, Mori K, Mikuni M, Nakamura Y, Matsuda M. Comparative study of redox reactions of polyaniline films in aqueous and nonaqueous solutions. Macromolecules. 1989, 22:3323-3327

Fosong W, Jinsong T, Lixiang W, Hongfang Z, Zhishen M. Study on the Crystallinity of Polyaniline. Mol Cryst Liq Cryst. 1988, 160:175-184

Pron A, Genoud F, Menardo C, Nechschein M. The effect of the oxidation conditions on the chemical polymerization of polyaniline. Synth Met. 1988, 24:193-201

Thyssen A, Borgerding A, Schiltze JW. Formation and electronic conductivity of polyaniline. Makromol Chem Macromol Symp. 1987, 8:143-157

Schacklette LW, Baughman RH. Defect Generation and Charge Transport in Polyaniline. Mol Cryst Liq Cryst. 1990, 189:193-212

Ryu KS, Moon BW, Joo J, Chang SH. Characterization of highly conducting lithium salt doped polyaniline films prepared from polymer solution. Polymer. 2001, 42:9355-9360

MacDiarmid AG, Epstein AJ. Secondary doping in polyaniline. Synth Met. 1995, 69:85-92.

Tanaka J, Mashita N, Mizoguchi J, Kume, K. Molecular and electronic structures of doped polyaniline. Synth. Met. 1989, 29:175-184

Conklin, JA, Huang, SC, Huang, SM, Wen, T, Kaner, RB. Thermal Properties of Polyaniline and Poly(aniline-co-o-ethylaniline). Macromolecules 1995, 28:6522-6527

Kaner RB, MacDiarmid AG. Plastics that conduct electricity. Scientific America. 1988, 34:60-65

Alexander M, Dubois P. Polymer-layered silicate nanocomposites: preparation, properties and uses of a new class of materials. Materials Science and Engineering: R: Reports. 2000, 28:1-63

Kargirwar SR, Thakare SR, Choudhary MD, Kondawar SB, Dhakate SR. Morphology and electrical conductivity of self-doping polyanilines synthesized via self-assembly process. Adv Mat Lett 2011, 2: 397-401.

Scrosati B eds. Application of electroactive polymers. Chapman and Hall, London, UK, 1993

Dimitriev OP, Smertenko PS, Stiller B, Brehmer L. Polyaniline–transition metal salt complexes:insight into formation mechanisms. Synth Met. 2005, 149:187-192

Catedral MD, Tapia AKG, Sarmago RV. Effect of Dopant Ions on the Electrical Conductivity and Microstructure of Polyaniline (Emeraldine Salt). Science Diliman. 2004, 16:41-46

Ravikiran YT, Lagare MT, Sairam M, Mallikarjuna NN, Sreedhar B, Manohar S, MacDiarmid AG. Synthesis, characterization and low frequency AC conduction of polyaniline/niobium pentoxide composites, Synth Met. 2006, 156:1139-1147

Chandrakanthl N, Careem MA. Thermal stability of polyaniline. Polymer Bulletin. 2000, 44:101-108


  • There are currently no refbacks.

AJPSE(ISSN 2572-5734)Copyright © 2012-2021. All rights reserved. Published by Ivy Union Publishing, 3204 Valley Rush Dr, Apex, North Carolina 27502, United States