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Reference Module in Chemistry, Molecular Sciences and Chemical Engineering || Polymer Electrodes: Preparation, Properties, and Applications☆
摘要： Good electric conductivity acquired through redox processes is the flagship property of polymers containing extended conjugated p-electron systems. It was discovered by Heeger and MacDiarmid in polyacetylene synthesized by Shirakawa’s method. Polyacetylene is chemically the simplest example amongst a vast collection of such materials, but it is environmentally unstable. Instead, polyheteroaromatics, such as polypyrrole and polythiophene, and polyaniline (polyphenylamine), as well as their derivatives, are of foremost interest because of applications in analytical sensors, power sources, separation devices, optoelectronic devices, and controllable platforms of chemical and biochemical reactions.
关键词： Preparation,Applications,Polythiophene,Polypyrrole,Properties,Polymer Electrodes,Conducting Polymers,Polyaniline
更新于2025-09-10 09:29:36
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Carbon Nanotubes - Current Progress of their Polymer Composites || Carbon Nanotube-Conducting Polymer Composites as Electrode Material in Electroanalytical Applications
摘要： This chapter gives a brief overview of the preparation, characterization, and analytical applications for combinations of polymers and carbon nanotubes (CNTs) that have been prepared in different ways, which are used as an electrode material. For this purpose, multiwalled or single-walled CNTs are composed of different types of conductive polymers. The preparation of CNT-conducting polymer composite electrodes was explained by their deposition order. Chemical and morphological surface characteriza‐ tions of composite electrodes were presented by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. In addition, CNT-based polymer composite electrode usage in sensor applications for trace organic/inorganic compounds and energy applications is discussed in the last part of this chapter.
关键词： composite electrodes,conducting polymers,electron microscopy,Carbon nanotubes,metal nanoparticels scanning
更新于2025-09-10 09:29:36
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Semiconducting Polymer Spherulites-From Fundamentals to Polymer Electronics
摘要： The control of the morphology of semiconducting semicrystalline polymers is crucial to the performance of various electronic devices. Among other superstructures in semicrystalline polymers, spherulites stand out for various reasons. They are highly ordered, relatively easy to grow, and their underlying molecular structure provides anisotropic optical and electronic properties of the resulting polymeric material. In this feature article, a short overview of classical crystallization theory is given as well as a brief introduction to spherulites as supermolecular structures. The article then focuses on semicrystalline polymers with semiconducting properties. From classical melt crystallization toward solvent vapor annealing, different strategies of growing spherulites of these types of polymers are presented and examples of the corresponding polymers and their resulting morphology are given. Eventually, the potential application of spherulitic thin films in organic electronics such as field-effect transistors is demonstrated. Conductivity and mobility measurements are shown, particularly focusing on the anisotropy of the latter.
关键词： optical properties,spherulites,conducting polymers,crystallization,electronic properties
更新于2025-09-09 09:28:46
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Porous Multilayered Films Based on poly(3,4- ethylenedioxythiophene) and poly(indole-5-carboxylic acid) and Their Capacitance Performance
摘要： Layer-by-layer (LBL) technique is a prevalent way to construct multilayered films. Herein, using high conducting poly(3,4-ethylenedioxythiophene) (PEDOT) and good stable redox-active poly(indole-5-carboxylic acid) (5-PICA), an alternately multilayered porous films has been prepared by the electrochemical LBL method. The alternately multilayered films were characterized by scanning electron microscope (SEM), cyclic voltammetry (CV), galvanostatic charge-discharge (CD) and electrochemical impedance spectroscope (EIS) techniques. Compared with monolayered PEDOT (147.8 F g-1) and 5-PICA(198.3 F g-1), the PEDOT/5-PICA/PEDOT/5-PICA 4-layered film exhibited a higher specific capacitance which reached 281.7 F g-1 at 20 A g-1 in 1.0 M H2SO4 solution. Furthermore, the specific capacitance of 4-layered film still had good stability, viz., 73% retention after 1000 cycles at the range of potential -0.15 to 1.0 V and even reached 95% if the potential range was from -0.15 to 0.8 V. Therefore, these results indicated that the PEDOT/5-PICA/PEDOT/5-PICA was a potential electrode material for supercapacitors.
关键词： Specific capacitance,Layer-by-layer films,Electropolymerization,Conducting polymers
更新于2025-09-09 09:28:46
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Stable Hall voltages in presence of dynamic quasi-continuum bands in poly(3,4-ethylene-dioxythiophene)
摘要： Topological and thermal disorder complicate the mobility characterization in poly(3,4-ethylenedioxythiophene) systems and presently leaves the exact transport mechanisms not fully understood. Here we show that ac-Hall measured by lock-in amplifier is able to resolve the Hall voltage in semimetallic polymers between room temperature and 32 K. These results are evaluated using an organic random phase model. This accounts for the role of tail states and, particularly, for thermal disorder of molecular semiconductors. We report band mobilities up to 3.7 cm2 V?1 s?1 in semimetallic polymers occurring in delocalized bands that originate from significant electron coherence across the polymer chains.
关键词： Weak localization,Conducting polymers,PEDOT,Hall-effect,Organic phase model,Electron coherence
更新于2025-09-04 15:30:14
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Polarons, bipolarons, and absorption spectroscopy of PEDOT
摘要： Electronic structure and optical absorption spectra of poly(3,4-ethylenedioxythiophene) (PEDOT) for different oxidation levels were studied using density functional theory (DFT) and time-dependent DFT. It is shown that the DFT-based predictions for the polaronic and bipolaronic states and the nature of corresponding optical transitions are qualitatively different from the widely used traditional picture based on semi-empirical pre-DFT approaches that still dominate the current literature. Based on the results of our calculations, the experimental Vis/NIR absorbance spectroscopy and the electron paramagnetic resonance spectroscopy are re-examined and a new interpretation of the measured spectra and the spin signal which is qualitatively different from the traditional interpretation is provided. The findings and conclusions concerning the nature of polaronic and bipolaronic states, band structure and absorption spectra presented for PEDOT, are generic for a wide class of conducting polymers (such as polythiophenes and their derivatives) that have similar structure of monomer units.
关键词： Vis/NIR absorbance spectroscopy,PEDOT,conducting polymers,Polarons,electron paramagnetic resonance spectroscopy,bipolarons
更新于2025-09-04 15:30:14
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Dithienobenzimidazole‐containing conjugated donor–acceptor polymers: Synthesis and characterization
摘要： The synthesis of two new conjugated polymers based on the relatively under-exploited monomer, 5,8-dibromo-2-[5-(2-hexyldecyl)-2-thienyl]-1H-dithieno[3,2-e:20,30-g]benzimidazole (dithienobenzimidazole, DTBI), and either 4,7-bis[4-hexyl-5-(trimethylstannyl)-2-thienyl]-2,1,3-benzothiadiazole (BTD) or 2,6-bis(trimethylstannyl)-4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b0]dithiophene (BDT) is described. The polymers were synthesized via Stille polycondensation and characterized by traditional methods (1H NMR, gel-permeation chromatography, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, thermal gravimetric analysis, differential scanning calorimetry, ultraviolet–visible spectroscopy, photoluminescence, and cyclic voltammetry). Prior to their synthesis, trimer structures were modeled by DFT calculations facilitating a further understanding of the systems’ electronic and geometric structure. Polymers were titrated with acid and base to take advantage of their amphiprotic imidazole moiety and their optical response monitored with ultraviolet–visible spectroscopy. Finally, pristine polymer thin-films were treated with acid and base to evaluate (de)protonation’s effect on system electronics, but thin-film degradation was encountered.
关键词： addition polymerization,synthesis,conjugated,conducting polymers,semiconducting polymer,dithienobenzimidazole,ionomers,donor–acceptor
更新于2025-09-04 15:30:14
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Electrochemical SERS for in situ Monitoring the Redox States of PEDOT and Its Potential Application in Oxidant Detection
摘要： In response to recent developments for applying conducting polymers on various biomedical applications, the development of characterization techniques for evaluating the states of conducting polymers in liquids is beneficial to the applications of these materials. In this study, we propose a platform using electrochemical surface-enhanced Raman scattering (EC-SERS) technology, which allows a direct measurement of the redox states of conducing polymers in liquids. A thiophene-based conducting polymer, hydroxymethyl poly(3,4-ethylenedioxythiophene) or poly(EDOT-OH), was used to demonstrate this concept. Poly(EDOT-OH) films were coated on Au nanoparticle-coated ITO glass as SERS-active substrates. Taking the advantage of Raman enhancement, we are able to in situ and clearly monitor the redox behavior of poly(EDOT-OH) in aqueous solutions. The Raman peak intensity decreases as the poly(EDOT-OH) film is oxidized. Furthermore, we demonstrated our idea to utilize this phenomenon as the sensing mechanism for oxidant detection. The Raman intensity of conducting polymers reduces faster when oxidants exist and we obtain a quantitative analysis for the detection of oxidants. Moreover, the oxidized poly(EDOT-OH) films can be reused for detection of oxidants simply by applying a reduction potential to activate the poly(EDOT-OH) films. The film stability was also confirmed and the detection of two other oxidants, namely ammonium persulfate and iron chloride, were also demonstrated. The results show different SERS spectra of poly(EDOT-OH) films oxidized by using different oxidants. Besides, the oxidized films can be easily recovered simply by applying a cathodic potential, which allows repeating usage and makes it possible for continuous monitoring applications. To the best of our knowledge, this is the first time to apply PEDOT’s Raman feature for detection purpose.
关键词： oxidant detection,electrochemical surface-enhanced Raman scattering,spectroelectrochemistry,conducting polymers,redox behavior
更新于2025-09-04 15:30:14