Fabrication of poly(3,4‐ethylenedioxythiophene)‐polysaccharide composites

Poly(3,4‐ethylenedioxythiophene) (PEDOT) doped with a series of anionic polysaccharides such as carboxymethyl cellulose, sodium hyaluronate, xanthan gum, pectin, gellan gum were prepared by electropolymerization in aqueous solutions. Some other dopants of potassium nitrate, potassium sulfate, sodium poly(styrenesulfonate), and sodium polyacrylate were used in comparison with the anionic polysaccharides. The electrochemical properties and stability of the obtained PEDOT films were also investigated. It was found that indium tin oxide (ITO) conductive glass could be used as the working electrode of the electropolymerization of EDOT and that the dopant had a great influence on polymerization potential and overoxidation potential. These charged biomolecules of anionic polysaccharides were found to facilitate electropolymerization of EDOT instead of common doping anions as counterion. The electroactive PEDOT films doped with anionic polysaccharides showed stable electrochemical properties, good texture, and adhesion properties to the ITO conductive glass. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation and characterization of aqueous dispersions of poly(3,4‐ethylenedithiathiophene‐co‐3,4‐ethylenedioxythiophene)/ poly(styrene sulfonate) and their conducting films

The chemical oxidative copolymerization of 3,4‐ethylenedithiathiophene (EDTT) with 3,4‐ethylenedioxythiophene (EDOT) and 2′‐hydroxymethyl‐3,4‐ethylenedioxythiophene in a poly(styrene sulfonic acid) aqueous solution was successfully carried out to form stable, dark blue colloidal dispersions in water. Coating these dispersions onto polypropylene substrates led to the formation of free‐standing copolymer films. The mechanical, electrical, and thermoelectrical properties of these films were investigated; the films showed superior properties in comparison with those of poly(3,4‐ethylenedithiathiophene) (PEDTT)/poly(styrene sulfonate) (PSS). The copolymer film based on EDTT and EDOT achieved a high electrical conductivity (8.2 × 10^?2 S cm^?1) at 298 K; this could be improved about 10 times through the addition of dimethyl sulfoxide (DMSO) or DMSO/isopropyl alcohol into the polymer dispersion with almost constant Seebeck coefficients of about 9 μV K^?1. On the contrary, these additives had almost no effect on the conductivity of PEDTT/PSS. The structure and morphology of the polymer films were studied by X‐ray diffraction and SEM analyses. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Dielectric and conductivity relaxation in poly(3,4‐ethylenedioxythiophene) nanotubes

The charge carriers relaxation dynamics in synthesized poly(3,4‐ethylenedioxythiophene) nanotubes has been investigated as a function of frequency and temperature through the framework of dielectric permittivity, modulus formalism and impedance formalism. The fitting of experimental data of real part of dielectric permittivity and imaginary part of modulus with Havriliak‐Negami equation and Bergman modified Kohlrausch‐Williams‐Watts function indicates the presence of non‐Debye type relaxation process in the synthesized poly(3,4‐ethylenedioxythiophene) nanotubes. The scaling of imaginary part of modulus and impedance formalisms have been performed to understand the charge carrier relaxation dynamics in the synthesized samples, which suggests the presence of time temperature superposition principle in the nanotubes. The red shifting of the band from 1440 cm^?1 to 1430 cm^?1 in micro‐Raman spectra indicates the conformational transition from benzenoid to quinoid structure with increasing dopant concentration. The linear increase of imaginary part of dielectric permittivity with decreasing frequency is ascribed to the higher contribution from dc conductivity as compared to that from the electrode polarization effects. POLYM. ENG. SCI., 56:448–457, 2016. © 2016 Society of Plastics Engineers     

Modified solution technique for preparing poly(3,4‐ethylenedioxythiophene) and a Poly(3,4‐ethylenedioxythiophene)/silver nanocomposite: Optical and thermal behavior

In this study, we prepared poly(3,4‐ethylenedioxythiophene) (PEDOT) via the chemical oxidation of the 3,4‐ethylenedioxythiophene monomer in a system consisting of miscible binary organic solvents, that is, acetonitrile (CH₃CN) and chloroform (CHCl₃). This successful technique was then used to synthesize a poly(3,4‐ethylenedioxythiophene) (PEDOT)/silver (Ag) nanocomposite as well. In this facile and efficient technique, a higher solubility of the oxidizing reagent, which originated from a relative enhancement in the polarity of the reaction medium, led to significant changes in the optical and thermal behaviors of the resulting products. To investigate the degree of validity of the technique applied, a pure sample of PEDOT (PEDOT I) was also synthesized with CHCl₃ alone, and this was then compared with a sample prepared in CH₃CN/CHCl₃ binary solvents (PEDOT II). To prepare the PEDOT/Ag nanocomposite, first the PEDOT synthesized in binary solvents was thoroughly dissolved in a dimethyl sulfoxide solvent. Next, Ag nanopowder was uniformly dispersed in the previous solution of PEDOT with sonication. The PEDOT/Ag nanocomposite was then precipitated through the addition of a methanol nonsolvent. The approximate size of nano‐Ag within the polymer matrix was found to be about 40 nm. Scanning electron microscopy images of the pure PEDOT II and PEDOT/Ag nanocomposite exhibited an agglomerated sponge and nanospherical homogeneity, respectively. In comparison with PEDOT I, considerable redshifts in the ultraviolet–visible absorption spectra of the pure PEDOT II and PEDOT/Ag nanocomposite were observed. In addition, the thermostability order was found to be PEDOT/Ag > PEDOT II > PEDOT I at all temperatures above 300°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2707–2712, 2013     

Feasibility of conducting semi‐interpenetrating networks based on a poly(ethylene oxide) network and poly(3,4‐ethylenedioxythiophene) in actuator design

A new type of synthetic pathway—the use of interpenetrating polymer networks (IPNs)—is proposed to design conducting polymer‐based actuators. Two types of materials with interesting conducting properties were prepared: (1) a semi‐IPN between poly(3,4‐ethylenedioxythiophene) (PEDOT) and branched poly(ethylene oxide) (PEO) network; (2) a tricomponent IPN between PEDOT and a PEO/polycarbonate (PC)–based network as the ionic conducting partner. In the first case, the influence of the amount of branching in the PEO network on the EDOT uptake and electrochemical properties was studied. A maximum conductivity (15 S cm^?1) was obtained for 60 wt % branched PEO in the material. Moreover, the dispersion profile of PEDOT in the material was shown by elemental analysis and energy dispersion spectroscopy to follow a gradient through the thickness of the film leading to a built‐in three‐layered device. With respect to PEO/PC materials, the best results were obtained for about 80 wt % PEO in the matrix where the material remains sufficiently elastomeric. In this case, the conductivity reaches about 1 S cm^?1 for a 10 to 30 wt % polycarbonate content. These materials are capable of reversible 45° angular deflections under a 0.5V potential difference. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3569–3577, 2003     

Synthesis of poly(3,4‐ethylenedioxythiophene) nanoparticles via chemical oxidation polymerization

Poly(3,4‐ethylenedioxythiophene) (PEDOT) nanoparticles were synthesized via chemical oxidation polymerization using 3,4‐ethylenedioxythiophene as the starting monomer and ammonium peroxydisulfate (APS) as the oxidant. The effects of APS concentration, surfactant concentration and type of surfactant, namely dodecylbenzenesulfonic acid and sodium dodecylsulfate, were investigated. Distinct particle shapes were obtained: irregular, raspberry agglomerate, coralliform, orange‐peel, globular and plum shapes. The particle sizes and the electrical conductivity are in the ranges 60 to 900 nm and <1 to 153 S cm^?1, respectively, depending on the polymerization conditions. PEDOT synthesis in the absence of a surfactant yields a smaller particle size because a larger amount of initiator induces lower molecular weights and smaller PEDOT particles. The smaller PEDOT particles correspond to higher electrical conductivity because of the larger surface areas for electron transfer and a smaller amount of obstructing surfactant aliphatic segments. Moreover, particle size and shape can be varied, depending on surfactant type and concentration which dictate the micellar shapes in the polymerization reaction. This work is focused on the tailor‐made PEDOT shape and property relationship under synthesis conditions where several shapes have not been previously seen. © 2013 Society of Chemical Industry     

Facile preparation of poly(3,4‐ethylenedioxythiophene) nanoparticles via a miniemulsion polymerization process

Poly(3,4‐ethylenedioxythiophene) (PEDOT) nanoparticles were prepared via a miniemulsion polymerization process. The chemical oxidative polymerization of 3,4‐ethylenedioxythiophene (EDOT) occurred in the presence of β‐1,3‐glucan with the injection of an aqueous oxidant solution, and the nanodroplets of EDOT were transformed to PEDOT nanoparticles dispersed in the aqueous medium. The aqueous emulsion of PEDOT nanoparticles showed relatively long emulsion stability (> 8 weeks), and the recovered solid nanoparticles were also redispersible in deionized water without deposition. The size and size distribution of PEDOT nanoparticles could be controlled by adjusting the operating conditions of the ultrasonifier before the polymerization process. The building‐up of a shearing force decreases the size of the PEDOT nanoparticles and also causes the occurrence of a multimodal size distribution for the PEDOT nanoparticles. The electrical conductivity of the PEDOT nanoparticles was 0.28–1.20 S cm⁻¹. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and electrochemical capacitance of poly(pyrrole‐co‐aniline)

The copolymer of pyrrole and aniline, poly(pyrrole‐co‐aniline), has been prepared by chemical oxidation of corresponding monomer mixtures with ammonium peroxysulfate. Techniques of FTIR, SEM‐EDS, and BET surface area measurement were used to characterize the structure and morphology of the copolymer. The electrochemical properties of the copolymer were investigated by cyclic voltammetry, galvanostatic charge‐discharge, and electrochemical impedance spectroscopy. The results indicated that poly(pyrrole‐co‐aniline) was about 100–300 nm in diameter and showed better electrochemical capacitive performance than polypyrrole and polyaniline. The specific capacitance of the copolymer electrode was 827 F/g at a current of 8 mA/cm² in 1 mol/L Na₂SO₄ electrolyte. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Electrochemical synthesis and characterization of poly(pyrrole‐co‐ε‐caprolactone) conducting copolymer

The direct electrochemical copolymerization of pyrrole (Py) and ε‐caprolactone at various monomer ratios was carried out by potentiostatic methods in nitromethane. Characterizations of the novel copolymer were based on scanning electron microscopy, differential scanning calorimetry, thermal gravimetrical analysis, cyclic voltammetry, electrochemical impedance spectroscopy, Fourier transform infrared spectra, and elemental analysis studies. The results showed that the electrochemical oxidation of Py and ε‐caprolactone comonomers generated true copolymers rather than blends of the two homopolymers. The electrical conductivity of the copolymers increased with the amount of polypyrrole in the copolymer between the value of 8.2 S/cm and 0.6 S/cm. A probable mechanism of copolymerization was proposed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of poly(3,4‐ethylenedioxythiophene)/poly(lactic acid) nanofibres by electrospinning

The poly(3,4‐ethylenedioxythiophene) (PEDOT) family of polymers is a technologically important class of conducting polymers showing high stability, medium band gap, low redox potential and high optical transparency in the electrically conductive state. While PEDOT nanotubes and nanofibres have been synthesized electrochemically, significant opportunity exists for developing a convenient chemical synthetic route for the bulk synthesis of nanostructured PEDOT for potential use in the design of next‐generation nano‐electronic circuits and field emission devices. In this paper, chemical oxidative polymerization was used to synthesize PEDOT nanoparticles. These nanoparticles were co‐electrospun with poly(l ‐lactic acid) from a solution in acetone and N,N‐dimethylformamide. The PEDOT particles were analysed using attenuated total reflectance–Fourier transform infrared spectroscopy and particle size distribution using dynamic light scattering. The synthesized nanofibre mats were studied using differential scanning calorimetry and scanning electron microscopy, and conductivity was measured using a two‐probe conductivity tester. © 2016 Society of Chemical Industry     

Electrical resistance measurement methods and electrical characterization of poly(3,4‐ethylenedioxythiophene)‐coated conductive fibers

Textile fibers and yarns of high conductivity, and their integration into wearable textiles for different electronic applications, have become an important research field for many research groups throughout the world. We have produced novel electrically conductive textile yarns by vapor‐phase polymerization (VPP) of a conjugated polymer, poly(3,4‐ethylenedioxythiophene) (PEDOT), on the surface of commercially available textile yarns (viscose). In this article, we have presented a novel setup for electrical resistance measurements, which can be used not only for fibrous structures but also for woven structures of specific dimensions. We have reported a two‐point resistance‐measuring method using an already manufactured setup and also a comparison with the conventionally used method (so‐called crocodile clip method). We found that the electrical properties of PEDOT‐coated viscose fibers strongly depend on the concentration of oxidant (FeCl₃) and the doping (oxidation) process of PEDOT. To evaluate the results, we used mass specific resistance values of PEDOT‐coated viscose yarns instead of normal surface resistance values. The voltage–current (V–I) characteristics support the ohmic behavior of coated fibers to some extent. Monitoring of the charging effect of the flow of current through conductive fibers for prolonged periods of time showed that conductivity remains constant. The change in electrical resistance values with increase in the length of coated fibers was also reported. The resistance‐measuring setup employed could also be used for continuous measurement of resistance in the production of conductive fibers, as well as for four‐point resistance measurement. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of alcoholic solvents on the conductivity of tosylate‐doped poly(3,4‐ethylenedioxythiophene) (PEDOT‐OTs)

The effects of alcoholic solvents on the charge transport properties of tosylate‐doped poly(3,4‐ethylenedioxythiophene) (PEDOT‐OTs) are investigated. The use of different alcoholic solvents in the oxidative chemical polymerization of 3,4‐ethylenedioxythiophene (EDOT) with iron(III)‐p‐tosylate led to a change in the electrical conductivity of PEDOT‐OTs. For example, PEDOT‐OTs prepared from methanol shows a conductivity of 20.1 S cm^?1 which is enhanced by a factor of 200 as compared to PEDOT‐OTs prepared from hexanol. The variation of charge transport properties on the use of different alcoholic solvents is consistent with the data recorded by UV‐visible and electrospin resonance (ESR) measurements. From XPS experiments, the PEDOT‐OTs samples prepared from different alcoholic solvents were found to have almost the same doping level, suggesting that the number of charge carriers is not responsible for the change in conductivity. Supported by XRD results, it was found that the use of alcoholic solvents with shorter chain length induces more efficient packing of PEDOT chains. It is proposed that the alcoholic solvents associated with the counter ion of PEDOT via hydrogen bonding give rise to a change in the molecular ordering of PEDOT chains during the polymerization step, hence enhancing or depressing the inter‐chain hopping rate of the resulting PEDOT‐OTs. Copyright © 2005 Society of Chemical Industry     

Different properties for poly(3,4‐ethylenedioxythiophene) films derived from single or multiple polymerization steps

Films of poly(3,4‐ethylenedioxythiophene) were prepared with single and multiple electropolymerization steps, where the numbers of polymerization steps (n's) were 3, 5, and 7, with identical experimental conditions and total polymerization times (τ's). The electroactivity of the films prepared with multiple steps remained almost unaltered when n increased, with the ability of the films to store charge with n > 3 being smaller than that of the films with similar thicknesses but derived from a single electrodeposition step. In contrast, the stability of the films produced with n polymerization steps was significantly higher than that of the films derived from a single step with the same τ, with the difference between the two systems increasing with n, that is, τ used to yield the films. On the other hand, although the morphological and topological characteristics of the surface and the electrical conductivity were affected by the procedure used to produce the films, the organization of the polymer molecules in the crystalline phase, the thermal stability, and the electronic properties (ionization potential, electron affinity, and lowest π–π* transition energy) were practically identical in both cases. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of microstructure on the dielectric properties of poly(vinyl alcohol)–poly(3,4‐ethylenedioxythiophene) doped with poly(styrenesulfonate) composite films

Poly(3,4‐ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT–PSS) was blended with poly(vinyl alcohol) (PVA) to form 0, 10, 20, 30, 40, and 50 vol % PEDOT–PSS/PVA solutions, and their freestanding films were prepared with a simple and cost‐effective solution casting technique at 27 °C in the absence of additives. Field emission scanning electron microscopy images revealed changes in the cocontinuous network to a rodlike morphology in the composite films from 10 to 50 vol % PEDOT–PSS/PVA. The alternating‐current conductivity was found to obey Jonscher's power law. The obtained values of the dielectric constant at 27 °C were relatively high, and a maximum value of 6.7 × 10⁴ at 100 Hz for 40 vol % PEDOT–PSS'/PVA was observed. The dielectric loss attained a maximum value of about 10⁶ at 100 Hz for 40 vol % PEDOT–PSS/PVA. However, a decrease in the dielectric parameters was observed at 50 vol % PEDOT–PSS/PVA because of locally induced strain in the microstructure. The variations in polarization with respect to the applied electric field (P–E) were determined for 50, 100, and 500 Hz at 500 V for the freestanding composite films of lower concentrations up to 20 vol % PEDOT–PSS/PVA. In summary, the dielectric and P–E measurements confirmed that the electrical characteristics changed in accordance to the contribution from both resistive and capacitive sites in the PEDOT–PSS/PVA composites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45079.     

A highly oriented poly(3,4‐ethylenedioxythiophene) film: Facile synthesis and application for supercapacitor

A single crystal poly(3,4‐ethylenedioxythiophene) (PEDOT) film with highly oriented arrangement has been fabricated from an aqueous solution by a novel unipolar pulse electropolymerization method. Film formation mechanism was proposed based on the in situ mass change during electropolymerization process measured by the electrochemical quartz crystal microbalance. The compositions, morphology and crystal structure of the fabricated films are characterized by Fourier transfer infrared spectroscopy, scanning electron microscopy, and X‐ray diffraction, respectively. It is found that the prepared PEDOT film on carbon nanotubes (CNTs)‐modified electrode with a spongy dendritic structure possesses outstanding electroactivity, high specific capacitances (239.1 F?g^?1, including the specific capacitances of CNTs which is 21.4 F?g^?1), and excellent cycling stability with 7.3% decay from its initial capacitance over 10,000 cycles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43418.     

Electroconductive paper prepared by coating with blends of poly(3,4‐ethylenedioxythiophene)/poly(4‐styrenesulfonate) and organic solvents

Electroconductive papers were produced by coating commercial base papers with blends of poly(3,4‐ethylenedioxythiophene)/poly(4‐styrenesulfonate) (PEDOT:PSS) and organic solvents. The bulk conductivities of the coated papers were measured using a four‐probe technique. One‐sided and two‐sided coating gave comparable conductivity levels. The presence of sorbitol and isopropanol in the PEDOT:PSS blends did not enhance the bulk conductivity of the coated paper, and with increasing concentrations of these solvents, the conductivity decreased due to dilution of the conducting component. Samples coated with PEDOT:PSS blends containing N‐methylpyrrolidone (NMP) or dimethyl sulfoxide (DMSO) exhibited a higher conductivity than those coated with pure PEDOT:PSS because of their plasticizing effect and conformational changes of PEDOT molecules indicated by the red shift and disappearance of the shoulder peak at about 1442 cm^?1 in the Raman spectra of the coated samples. EDS imaging showed that PEDOT:PSS is distributed throughout the thickness direction of the paper. Contact angle measurements were made to monitor the hydrophilicity of the paper surface and total sulfur analysis was used to determine the amount of PEDOT:PSS deposited onto the paper. The tensile strength of all the paper samples increased slightly after treatment. Thus, it is demonstrated that enhanced bulk conductivity in the order of 10^?3 S/cm can be achieved by using organic conductive materials and surface treatment techniques. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of biodegradable block copolymers of poly(propylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) and poly(ethylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol)

The synthesis of two low molecular weight linear unsaturated oligoester precursors, poly(propylene fumarate‐co‐sebacate) (PPFS) and poly(ethylene fumarate‐co‐sebacate) (PEFS), are described. PPFS, PEFS, and poly(ethylene glycol) are then used to prepare poly(propylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) (PPFS‐co‐PEG) and poly(ethylene fumarate‐co‐sebacate)‐co‐poly(ethylene glycol) (PEFS‐co‐PEG) block copolymers. The products thus obtained are investigated in terms of the molecular weight, composition, structure, thermal properties, and solubility behavior. A number of design parameters including the molecular weights of PPFS, PEFS, and PEG, the reaction time in the polymer synthesis, and the weight ratio of PEG to PPFS or to PEFS are varied to assess their effects on the product yield and properties. The hydrolytic degradation of PPFS‐co‐PEG and PEFS‐co‐PEG in an isotonic buffer (pH 7.4, 37°C) is investigated, and it is found that the fumarate ester bond cleaves faster than does the sebacate ester bond. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 295–300, 2004     

ABTS•+ scavenging activity of polypyrrole,polyaniline and poly(3,4‐ethylenedioxythiophene)

Although many methods are available for the evaluation of the antioxidant capacity of samples presented in the liquid state, typically food and beverages, to date only the 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH) assay has been applied to the measurement of the antioxidant capacity of solid samples such as active packaging materials. A modified 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt (ABTS) assay has been successfully developed for the measurement of the antioxidant capacity of conducting polymer powders. The ABTS^?+ radical scavenging activity of polypyrrole (PPy), polyaniline (PANI) and poly(3,4‐ethylenedioxythiophene) (PEDOT) powders was compared. The ranking order for greatest antioxidant capacity among the conducing polymer powders was PANI > PPy > PEDOT. The reduced forms of all the three conducting polymer samples were found to show greater radical scavenging activity than their as‐prepared partially oxidized forms. The modified ABTS assay is a simple, rapid and sensitive method for evaluating the antioxidant capacity of conducting polymer powders. The method is also suitable for composite antioxidant materials comprising a conducting polymer and a conventional packaging polymer. Copyright © 2010 Society of Chemical Industry     

Electrosynthesis,characterization, and application of poly(3,4‐ethylenedioxythiophene) derivative with a chloromethyl functionality

Poly(2‐chloromethyl‐2,3‐dihydrothieno[3,4‐b][1,4]dioxine), a chloromethyl functionalized poly(3,4‐ethylenedioxythiophene) derivative (PEDOT‐MeCl), was synthesized electrochemically via the potentiostatic polymerization of its monomer in dichloromethane solution containing suitable tetrabutylammonium tetrafluoroborate, then it was used for the characterization of film properties and the fabrication of electrochemical sensor. The properties of the resulting PEDOT‐MeCl film were characterized by different methods such as cyclic voltammetry, electrochemical impedance spectroscopy, Fourier transform infrared and ultraviolet–visible techniques, scanning electron microscope, and thermogravimetric analysis. The PEDOT‐MeCl film displayed a good reversible redox activity, remarkable capacitance properties, good thermal stability, rough, and porous structure, especially fluorescent spectra indicated that PEDOT‐MeCl was a blue‐emitter with maximum emission centered at 396 and 398 nm. Finally, the PEDOT‐MeCl film was employed for the fabrication of the sensing electrode, and dopamine was chosen as a model analyte for the application of the electrochemical sensor. Results indicated that the PEDOT‐MeCl film as sensing interface was feasible, and studies of these film properties were very beneficial for studying properties and applications of other poly(3,4‐ethylenedioxythiophene) derivative films. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2660–2670, 2013     

The influence of thermal cycling and compressive force on the resistance of poly(3,4‐ethylenedioxythiophene)/poly(4‐styrenesulfonic acid)‐coated surfaces

There is an increasing interest in the use of conducting polymers for a wide variety of applications. This includes the study and development of alternative contact‐connector materials. The main aim is to achieve overall improvements in performance as well as cost effectiveness. Currently, extrinsic conducting polymers (ECPs) are employed as conductive coats or adhesives at contact interfaces. However, frictional abrasion within the metal‐doped polymer (ECP) causes instability in the resistance. It is important to overcome this fretting effect, especially in automotive applications; hence, the possibilities of employing intrinsically conducting polymers (ICPs) are explored. Flat contact film coatings have been fabricated in‐house using poly(3,4‐ethylenedioxythiopene)/poly(4‐styrenesulfonic acid) (PEDOT/PSS) with dimethylformamide as the secondary solvent. Resistance is measured using the four‐wire method. The conductivities of the PEDOT/PSS‐coated contacts are found to be in the order of 10^?2 S cm^?1. The change of resistance under varying compression forces has been found to be repeatable. The thermal effects on these contacts are also studied and the results are depicted as exponential negative temperature coefficients of resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2445–2452, 2006