spin concentration of 8.2 × 10¹⁹. The results obtained from these techniques indicated

successful synthesis of polyfuran of good quality and stability.

19.3.6 Polythiophene (PTH)

Polythiophene is produced from oxidative polymerization of thiophene. This type of con­

ducting polymer is an important conjugated polymer whose structure is composed of an

aromatic ring with sulphur, a heteroatom present in the aromatic ring. The structure of

polythiophene is presented in Figure 19.3g. The sulfur atoms contained in the structure

of polythiophene are bonded to sp² hybridized carbons, which shows two lone pairs of

electrons available for interaction with other molecules. This offers polythiophene, the

property to interact and remove pollutants; hence, the application of polythiophene in rid­

ding the environment of pollutants. Polythiophene is a conducting polymer that forms stable

materials environmentally and thermally. Owing to this, polythiophene is used in sensors,

antistatic coating, solar cells, electrodes, smart windows, artificial noses, and muscles.

Polythiophene synthesis can be carried out by both electrochemical and chemical

oxidative-polymerization methods. The chemical oxidative-polymerization method of

polythiophene synthesis involves the use of oxidants such as FeCl3 by nickel catalyzed

reaction [11]. For example, Karim et al. synthesized polythiophene by gamma radiation-

induced chemical oxidative-polymerization method. The synthesis process involved

the use of anhydrous FeCl3 as oxidizing agents [12]. The electrochemical oxidative-

polymerization of polythiophene synthesis has been employed by Kaneto et al. [13] to

synthesize polythiophene films. The report stated that benzonitrile was used as the elec­

trolyte while the polymerization process occurred on an indium-tin-oxide anode. The

resultant polythiophene per the report exhibited better electrical conductivity than the one

synthesized using the chemical oxidative-polymerization method.

Synthesis methods that have been employed in the synthesis of poly(3,4-ethylene di­

oxythiophene) include hydrothermal method, interfacial polymerization, and reverse

microemulsion polymerization method. For example, Ahmed et al. [14] used the hy­

drothermal method to synthesize poly(3,4-ethylene dioxythiophene) for application in

high-performance supercapacitors. Also, the reverse microemulsion polymerization

method has been utilized by Siju et al. [15] to synthesize poly(3,4-ethylene dioxythio­

phene). The synthesis involved the use of hexane/water reverse microemulsion system,

sodium bis(2-ethylhexyl) sulfosuccinate cylindrical micelles as a template, and ferric

chloride as an oxidizing agent. Jang et al. [16] applied the surfactant-mediated interfacial

polymerization method to fabricate poly(3,4-ethylene dioxythiophene). The morphology

of the poly(3,4-ethylene dioxythiophene) fabricated was dependent on the concentration

of the surfactant used.

19.4 Application of Conductive Polymers for Metabolite Sensing

Detection of metabolites, is useful for diagnosis, drug analysis, quality and safety control

in the food industry, forensic investigation, and drug discovery. Due to their unique

properties, conductive polymers have been used in the development of sensors for di­

verse forms of metabolites. These include glucose, neurotransmitters, hormones, nucleic

acid, organic acid, phytochemicals, and food pathogens [17,18]. This section discusses

Conducting Polymer Composites

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