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Electroactive Polymers in Industry
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Adil A. Gobouri, Electroactive Polymeric Materials, 2022
Vivek Mishra, Shubham Pandey, Simran Aggarwal
Polyacetylene is the best example of a conductive polymer, with conductivity mainly determined by long chains of unsaturated carbon atoms that maintain an alternating double bond arrangement (Figure 16.24). The delocalized p-system is responsible for polyacetylene’s high conductivity when electrons can be visualized as a cloud traversing the polymer chains backbone. The conductivity of polyacetylene can be increased by doping it with Si or gallium arsenide. In polymers, p-type doping oxidizes the material, which eliminates electrons from the cloud, and n-type doping chemically reduces the material, which contributes electrons to the polymer. The excess electrons or holes usually move freely through the material that makes the polymer conductive.
Conducting Polymers
Published in Ram K. Gupta, Conducting Polymers, 2022
N. Raghavendra Naveen, Girirajasekhar Dornadula, Pamayyagari Kalpana, Lakshmi Narasimha Gunturu
Polyacetylene and its derivatives possess unique features such as photoconductivity, electrical conductivity, chiral recognization, and liquid crystal properties. The main chain of polyacetylene is composed of a linear polyene chain, which can be added with a few pendant groups to form monosubstituted or disubstituted polyacetylene (Figure 21.5). Polyacetylene, in its intact form, has a low conductivity (10−5 S/cm), whereas doping can rise the conductivity to 102–103 S/cm and also gives modulated optical-mechanical or electrochemical properties. There are many synthetic methods for the synthesis of polyacetylene, as depicted in Table 21.2.
Optical Properties of Solids
Published in Elaine A. Moore, Lesley E. Smart, Solid State Chemistry, 2020
Elaine A. Moore, Lesley E. Smart
As for polyacetylene, the conductivity of these polymers is sensitive to doping. This is exploited in polypyrrole gas sensors, which are based on the variation of conductivity of a thin polymer film when exposed to gases such as NH3 and H2S. Doped conducting polymers can also be used as a metallic contact in organic electronic devices.
DFT simulation of conductivity of the p-type doped and charge-injected cis-polyacetylene
Published in Molecular Physics, 2022
Kamrun N. Keya, Wenjie Xia, Dmitri Kilin
During the last few decades, many researchers have worked on the electronic conductivity of polyacetylene, and it gets great attention particularly because of the possibility of increasing its electrical conductivity by doping [23–25]. Heeger and co-workers suggested that solitons played a fundamental role in the charge-transfer doping mechanism [26]. Yamabe et al. studied the conducting mechanism in the direction perpendicular to the chains for lightly doped PA [27]. Based on their model, the charged soliton was helped to hop between the PA chains due to the vibrational motion of the dopant. However, most earlier models for conducting mechanisms were one-dimensional (1D) models, and not suited to the electrical anisotropy of the PA system. Detailed experiments have shown that the doped oriented-polyacetylene shows conductivity anisotropy in directions parallel and perpendicular to the oriented direction of the film [28,29]. Makoto Kuwabara et al. numerically investigated the interchain hopping of solitons and polarons in polyacetylene and observed that charge solitons can hop to the opposite chain by forming bipolarons [30]. R. R. Chance et al. studied the interchain hopping of bi-polarons of doped polyacetylene which was discussed as a mechanism for spinless conductivity. They observed that this mechanism can account for the observed dopant-concentration dependence of the conductivity in trans-polyacetylene and the observation of anomalously low magnetic susceptibilities in the highly conducting regime of several doped polymers [31]. Several researchers investigated that polyacetylene showed remarkable electronic properties in the films doped and undoped PA. It is important to explore the research on the conductivity of the conjugated polymer like cis-PA at the ground state and understand the influence of the electronic structure of the semiconducting CPs after adding doping or injection of charge carriers. The electronic properties, charge carrier density, and conductivity of the conjugated polymer can be improved by adding p- or n-type doping (charge injection) after adding those things to the CPs, the conductivity of the semiconducting material can be changed or modified [9].