Synthesis and electrochemical investigation of polyindole based fiber as sensor electrode by EIS method

Abstract

Fibers of Polyacrylonitrile/Polyindole were prepared by electrospinning method. Fourier transform infrared spectroscopy (FTIR), Atomic force microscopy (AFM) and Scanning electron microscopy (SEM) were used for their structural characterization. The synthesis and characterization results showed that the incorporation of indole moieties affected the characteristic and topological properties of the polyacrylonitrile fiber. The fiber diameter was closely dependent to the polymer blend solution, surface tension, solution conductivity and viscosity. The results obtained by using Electrochemical impedance spectroscopy (EIS) showed that the fiber diameter affected the electrical conductivity of the fibers. It was discussed that the presence of Polyindole (PIN) content showed an electrocatalytic activity against K 3 Fe(CN) 6 / K 4 Fe(CN) 6 depending on the synthetic conditions, preparation process and the structure of organic matrix.

Critical analysis of polyindole and its composites in supercapacitor application

“…Sample with 0.5% w/v PIN was found to have highest specific capacitance due to amorphous and porous fiber with limited PIN concentration (optimum) which provides maximum space for double layer capacitance and movement of ions of electrolyte. Impedance studies for PIN/PAN composite at different ionic concentration (K 3 Fe(CN) 6 /K 4 Fe(CN) 6 ) provide information on kinetics of electron transfer and diffusion mechanism, where resistance due to charge transfer and electrode resistance were found to decrease with increase in ionic concentration, while electrode capacitance and electrode power were found to increase [63]. PIN and PINCBT [poly(indole-6-carboxylic acid-co-2,2′-bithiophene)] composite were polymerised over ITO (Indium Tin Oxide) surface electrochemically to investigate electrochemical and electrochromic behaviour.…”

“…PAN inactivates the surface tension and it diminishes the weak intermolecular interaction between PIN and DMF when added to the matrix (exception being 2.0% w/v PIN in 10% PAN) ( Fig. 10) [63].…”

“…Significant differences in the pore size of PIN and CdSe-doped PIN (3:2) was discovered; with increased dopant in the PIN, the particle size and gap in between the particle get decreased due to higher crystallinity achieved. Due to addition of higher amount of CdSe in the PIN matrix, the activation energy is lowered, and electron hopping is easy; however, this [63] activation energy is lower for PIN as compared to PIN/CdSe composite probably due to coordination between the CP and the CdSe which restrict the movement of charge carrier also due to decrease mobility of π-electron [48].…”

Hydrotrope-assisted interconnected mesoporous polyindole-decorated carbon nanotubes: synthesis, characterisation, and fabrication of asymmetric supercapacitor

“…15 These challenges include pre and post-processing complications that chiefly arise owing to the initial selection of electrolyte or solvents compatible with indole. 16 Previously, several solvents or electrolytes have been preferred for polymerisation of indole by the scientific community, such as for chemical oxidation (chloroform, 17,18 methanol, 19 acetone, 20 ethanol 12 ), electrospinning (acetonitrile 21 ), emulsification (hydrochloric acid 22 with surfactant assistance 5 by cetyl trimethyl ammonium bromide (CTAB), sodium dodecyl sulphate (SDS), Tween 80 (TW80), or FeCl 3 ), electrochemical (acetonitrile 23 ) interfacial polymerisation (dichloromethane, 24 surfactant-assisted 25 ).…”