• Fulltext


        Click here to view fulltext PDF

      Permanent link:

    • Keywords


      Polypyrrole; haemoglobin; polymer composites; non-isothermal kinetics; thermodynamics; solid-state decomposition; DC conductivity.

    • Abstract


      Doping of haemoglobin (Hb) into polypyrrole (PPy) has afforded polymer composites (PCs) with improved semiconducting behaviour with retained thermal stability. Process of doping was conducted through cationic surfactantassisteddilute polymerization of pyrrole (0.12 mol dl$^{-1}$) in the presence of ferric chloride oxidant (1.85${\times}$10$^{-2}$ mol dl$^{-1}$) supplemented with requisite weight fractions of Hb (10 and 20%; w/w). Physicochemical features of PCs were examined through diverse spectral, thermal and microscopic methods. Thermogravimetric analysis (TG) coupled with differential thermal analysis and differential thermogravimetry reveals two-step decomposition of PCs at common TG onset with Hb and PPy (200°C). Energy of activation and frequency of thermal degradation of Hb, PPy and related PCs have been evaluated and compared through Coats–Redfern (CR) and Horowitz–Metzger (HM) methods. CR method reveals substantial modification in free energy change of thermal degradation (${\Delta}$G, kJ mol$^{-1}$) of PCs (132.90) over PPy (13.09). Doping of Hb (20 wt%) has rendered shift in energy bandgap of PPy from 3.09 to 2.99 eV. Working electrodes (WEs) were derived from PCs in the presence of sulphonated polysulphone binder in graphite matrix and investigated for direct current conductivity (${\sigma}$DC) measurement under four-probe conditions at temperature range 313–373 K. Arrhenius plots reveal progressive trend in carrier activation energy (meV) of PCs ranging from 1.08 to 1.16 up to 20 wt% doping of Hb. The present study delivers a viable method of preparation of WE from Hb-doped PPy with sustained semiconducting behaviour up to 373 K.

    • Author Affiliations



      1. Department of Chemistry, College of Basic Science and Humanities, G.B Pant University of Agriculture and Technology, Pantnagar, Uttarakhand 263145, India
    • Dates

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2022-2023 Indian Academy of Sciences, Bengaluru.