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     

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     

Synthesis of functionalizable derivatives of 3,4‐ethylenedioxythiophene and their solid‐state polymerizations

Four polythiophenes based on poly(3,4‐ethylenedioxythiophene) (PEDOT) framework have been successfully prepared by the facile thermal activated solid‐state polymerization (SSP) process from their corresponding dibromothiophene derivatives, which were efficiently obtained using our improved methodology. Rates of polymerizations of these precursors were varied and most of the processes were incomplete under the reaction condition chosen for the synthesis. Raising the reaction temperature of the SSP further advanced the polymerization progress and improved the conductive properties of the polymer. The polymer of 3,4‐ethylenedioxythiophene‐methanol (EDTM) and its two related derivatives with functionalizable groups were prepared for the first time by the SSP method. The process and these new SSP‐derived polymers could help solving the fabrication difficulty and expand the scope of their applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42233.     

Electrically conductive poly(3,4‐ethylenedioxythiophene)–polystyrene sulfonic acid/polyacrylonitrile composite fibers prepared by wet spinning

Composite conductive fibers based on poly(3,4‐ethylenedioxythiophene) (PEDOT)–polystyrene sulfonic acid (PSS) blended with polyacrylonitrile (PAN) were prepared via a conventional wet‐spinning process. The influences of the PEDOT–PSS content on the electrical conductivity, thermal stability, and mechanical properties of the composite fibers were investigated. The fibers with 1.83 wt % PEDOT–PSS showed a conductivity of 5.0 S/cm. The breaking strength of the fibers was in the range 0.36–0.60 cN/dtex. The thermal stability of the PEDOT–PSS/PAN composite fibers was similar to but slightly lower than that of the pure PAN. The X‐ray diffraction results revealed that both the pure PAN and PEDOT–PSS/PAN composite fibers were amorphous in phase, and the crystallization of the latter was lower than that of the former. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Multicolor electrochromism of low‐bandgap copolymers based on pyrrole and 3,4‐ethylenedioxythiophene: Fine‐tuning colors through feed ratio

The copolymerization of pyrrole with 3,4‐ethylenedioxythiophene (EDOT) is successfully achieved in boron trifluoride diethyl etherate via direct anodic oxidation of the monomer mixtures on indium‐tin oxide working electrodes. The resultant copolymers are characterized by electrochemical methods, FT‐IR, XPS, SEM, and spectroelectrochemical analysis. The copolymer films present excellent electrochromic properties especially the multicolor electrochromism which can be tuned through the feed ratio of pyrrole and EDOT. The neutral copolymer films exhibit blue‐shift with the increasing feed ratio of pyrrole and EDOT, and the calculated band gaps of the copolymers are as low as that of PEDOT film. Furthermore, the electrochemical and optical stability has been improved by the incorporation of EDOT units into the polymer chains. The copolymer prepared with the changing feed ratio of pyrrole and EDOT at 1/4 retains 71% of its original electroactivity after 500 cycles and 72% of its optical contrast after 500 steps. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation and characterization of polyaniline–1‐hydroxyethane 1,1‐diphosphonic acid salt and its application as a catalyst for the synthesis of N‐benzylidine‐2‐phenyl imidazo[1,2‐a]pyridines

A novel, efficient, and easily synthesizable catalyst, an emeraldine form of polyaniline (PANI)?1‐hydroxyethane 1,1‐diphosphonic acid salt (HEDP), was successfully synthesized and demonstrated as a reusable polymer‐based solid acid catalyst in the synthesis of N‐benzylidine‐2‐phenyl imidazo[1,2‐a]pyridines with 2‐aminopyridine with aromatic aldehydes and trimethyl silylcyanide at room temperature. PANI–HEDP was characterized by Fourier transform infrared spectroscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, field emission scanning electron microscopy, and conductivity measurements. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2995–3000, 2013     

Electropolymerization and properties of 3,4‐ethylenedioxythiophene backbone polymer with tetrathiafulvalene as pendant

Three 3,4‐ethylenedioxythiophene (EDOT) derivatives, including an EDOT‐tetrathiafulvalene (TTF) derivative, were synthesized by Steglich esterification of carboxylic acids with hydroxymethyl EDOT (3,4‐ethylenedioxythiophene methanol). The UV spectra showed that there was no distinctive intramolecular interaction for the EDOT–TTF monomer between the EDOT and the TTF moieties in the ground state; however, the cyclic voltammetry responses implied that such intramolecular interaction occurred. Electropolymerization in excessive potential could bring in strong overoxidation effects and degradation in the polymer film. The polymers were simulated using density functional theory with Gaussian03 package and the optimized HOMO and LUMO state were figured out. The conductivity of TTF‐polymer was 6 S·cm^?1 obtained by galvano station and 4.8 × 10^?3 S·cm^?1 obtained by potentiostatic electropolymerization after doping with 7,7,8,8‐tetracyanoquinodimethane. The results indicated that this polymer was a reasonable candidate for conducting materials and it was meaningful to increase the conductive dimensions of TTF polymers by chemical doping. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

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     

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     

Copolymerization of poly(1‐naphthylamine) with aniline and o‐toluidine

The commercial use of polyaniline has been impeded by its intractable nature and insolubility. The use of substituted polyaniline has been attempted mainly to increase the processibility of polyaniline, but this approach usually results in the lowering of the conductivity. This study reports the synthesis of poly(1‐naphthylamine), a fused ring derivative of polyaniline, and its copolymers with aniline and o‐toluidine via a chemical polymerization method. Spectral, thermal, morphological, and conductivity studies were carried out to elucidate the influence of the incorporation of aniline and o‐toluidine units into poly(1‐naphthylamine). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Didecyl ester of 4‐sulfophthalic acid as a plast dopant and emulsifier in the chemical polymerization of aniline into polyaniline salt

Polyaniline salt was synthesized through the chemical oxidation of aniline with sodium persulfate as the oxidant and didecyl ester of 4‐sulfophthalic acid via three different polymerization pathways (aqueous, emulsion, and interfacial). In these polymerization processes, the ester acted as a novel plast dopant and as an emulsifier. The yield, conductivity, and number of ester units present in the polyaniline salts were determined. A polyaniline salt prepared by emulsion polymerization was soluble in chloroform and showed excellent solution‐processing properties. Polyaniline samples prepared by aqueous or interfacial polymerization were not soluble in chloroform. A soluble polyaniline salt was successfully synthesized through the washing of an organic layer containing the polyaniline salt with water in emulsion polymerization. X‐ray diffraction spectra of polyaniline salts prepared by the three different methods showed an ordered, layer‐type supramolecular structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Copolymers of aniline and o‐methoxyaniline: Synthesis and characterization

High‐conversion (HC) copolymers of aniline and o‐methoxyaniline (o‐anizidine) were synthesized for the first time by chemical oxidative copolymerization using various polymerization techniques (simultaneous or consecutive introduction of comonomers into the polymerizing system). Low‐conversion (LC) copolymers have also been synthesized for comparison. The polymers obtained were characterized using ¹H‐NMR, infrared, and electronic absorption spectroscopy, differential scanning calorimetry, and electrical conductivity measurements. Solubility characteristics and composition of different fractions of the copolymers were also determined. It was shown that in contrast to the LC copolymers, HC copolymers reveal relatively poor solubility. Electrical conductivity of copolymers and also of o‐methoxyaniline homopolymer is lower compared to polyaniline, which correlates with notable hypsochromic (blue) shift of the bands in electronic absorption spectra. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 75–81, 2006     

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     

Copolymers of aniline and o‐methoxyaniline: Synthesis and characterization

High‐conversion (HC) copolymers of aniline and o‐methoxyaniline (o‐anizidine) were synthesized for the first time by chemical oxidative copolymerization by using various polymerization techniques (simultaneous or consecutive introduction of comonomers into the polymerizing system). Low‐conversion (LC) copolymers have also been synthesized for comparison. The polymers obtained were characterized by using ¹H‐NMR, infrared, and electronic absorption spectroscopy; differential scanning calorimetry; and electrical conductivity measurements. Solubility characteristics and composition of different fractions of the copolymers were also determined. It was shown that, in contrast to the LC copolymers, HC copolymers reveal relatively poor solubility. Electrical conductivity of copolymers and also of o‐methoxyaniline homopolymer is lower as compared to polyaniline, which correlates with notable hypsochromic (blue) shift of the bands in electronic absorption spectra. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1822–1828, 2005     

Highly conductive new aniline copolymers: poly(aniline‐co‐aminoacetophenone)s

Copolymers of aniline and o‐/m‐aminoacetophenone of different compositions were synthesized by oxidative chemical copolymerization. Two different methods were employed, emulsion and inverse emulsion, with different oxidants, ammonium persulphate and benzoyl peroxide, to study the effect of synthesis conditions on the yield, solubility and conductivity of the copolymers. The copolymer compositions were determined using proton NMR spectroscopy. The reactivity ratios determined by the Finemann–Ross method indicate lower reactivity for m‐aminoacetophenone relative to aniline in the emulsion method, while the reverse holds true in the inverse emulsion method. Copolymers formed by the former pathway are random type as determined by the Finemann–Ross method. The copolymers have crystalline/amorphous morphologies and good conductivity. They exhibit enhanced solubility compared with polyaniline. Copyright © 2005 Society of Chemical Industry     

Mechanochemical synthesis and characterization of poly(2,5‐dimethoxy aniline) salts

The interfacial interaction and orientation of molecules during the polymerization process plays a vital role in the enhancement of the surface properties of conducting polymers. In this perspective, a solid‐phase mechanochemical route is employed to prepare poly(2,5‐dimethoxy aniline) (PDMA) and its salts with superior properties. Various studies performed on the as‐prepared polymer highlights the formation of polymeric particles with excellent physicochemical properties. Elemental analysis showed the presence of dopants anion in the polymeric backbone. Spectroscopic profile of PDMAs revealed the formation of emeraldine form of PDMAs. Moreover, these studies indicate the formation of PDMA‐HCl in a highly doped state. The surface morphological pictures of PDMAs revealed the formation of aggregated microstructured to nanostructured particulates. X‐ray diffraction, cyclic voltammetry were used to evaluate the physicochemical properties of PDMAs. PDMA salts exhibited crystalline behavior and good electrochemical activity. TG/DTA analysis showed that all the PDMAs were thermally stable up to 240°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Electrochemical polymerization of fluoro‐ and chloro‐substituted anilines and copolymers with aniline

Poly(2‐fluroaniline) and poly(2‐chloroaniline) were synthesized by an electrochemical method in an acetonitrile solution containing tetrabutylammonium perchlorate and perchloric acid. Also, the electrochemical copolymerization of aniline with 2‐fluroaniline and 2‐chloroaniline was carried out in the same medium. Cyclic voltammograms of the deposited films were recorded in neutral, acidic, and basic solutions. The electrochemical behavior of the films showed the same characteristic results as conventional polyaniline. The observed decrease in the dry electrical conductivity of the copolymers with respect to polyaniline was attributed to the incorporation of the fluoro‐ and chloro‐substituted anilines into the polyaniline chain. Further characterization of the polymer and copolymer products was performed through dry electrical conductivity measurements, ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy. The relative solubility of the films was determined in various common organic solvents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2302–2312, 2004     

Synthesis and characterization of N‐ and O‐alkylated poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline]

Poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline] was synthesized in an aqueous hydrochloric acid medium with a determined feed ratio by chemical oxidative polymerization. This polymer was used as a functional conducting polymer intermediate because of its side‐group reactivity. To synthesize the alkyl‐substituted copolymer, the initial copolymer was reacted with NaH to obtain the N‐ and O‐anionic copolymer after the reaction with octadecyl bromide to prepare the octadecyl‐substituted polymer. The microstructure of the obtained polymers was characterized by Fourier transform infrared spectroscopy, ¹H‐NMR, and X‐ray diffraction. The thermal behavior of the polymers was investigated by thermogravimetric analysis and differential scanning calorimetry. The morphology of obtained copolymers was studied by scanning electron microscopy. The cyclic voltammetry investigation showed the electroactivity of poly [aniline‐co‐N‐(2‐hydroxyethyl) aniline] and N and O‐alkylated poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline]. The conductivities of the polymers were 5 × 10^?5 S/cm for poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline] and 5 ×10^?7 S/cm for the octadecyl‐substituted copolymer. The conductivity measurements were performed with a four‐point probe method. The solubility of the initial copolymer in common organic solvents such as N‐methyl‐2‐pyrrolidone and dimethylformamide was greater than polyaniline. The alkylated copolymer was mainly soluble in nonpolar solvents such as n‐hexane and cyclohexane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Inverted emulsion polymerization route to polyaniline‐3D nanofiber network using sulfonated‐p‐cresol as novel dopant

Sulfonated‐p‐cresol (SPC) was used as novel dopant for the first time in the synthesis of polyaniline in 3D nanofiber networks (PANI‐3D). Polyaniline in 3D nanofiber network was prepared using organic solvent soluble benzoyl peroxide as oxidizing agent in presence of SPC and sodium lauryl sulfate (SLS) surfactant via inverted emulsion polymerization pathway. The influence of synthesis conditions such as the concentration of the reactants, stirring/static condition, and temperature etc., on the properties and formation of polyaniline nanofiber network were investigated. Polyaniline in 3D nanofiber network with 40–160 nm (diameter), high yield (134 wt % with respect to aniline used), and reasonably good conductivity (0.1 S/cm) was obtained in 24 h time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of poly(aniline‐co‐o‐toluidine) coatings and their corrosion‐protection performance on low‐carbon steel

Strongly adherent poly(aniline‐co‐o‐toluidine) coatings were synthesized on low‐carbon‐steel substrates by the electrochemical copolymerization of aniline with o‐toluidine with sodium tartrate as the supporting electrolyte. These coatings were characterized with cyclic voltammetry, ultraviolet–visible absorption spectroscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and scanning electron microscopy. The formation of the copolymer with the mixture of monomers in the aqueous sodium tartrate solution was ascertained by a critical comparison of the results obtained from the polymerizations of the individual monomers, aniline and o‐toluidine. The optical absorption spectrum of the copolymer was drastically different from the spectra of the respective homopolymers, polyaniline and poly(o‐toluidine). The extent of the corrosion protection offered by poly(aniline‐co‐o‐toluidine) coatings to low‐carbon steel was investigated in aqueous 3% NaCl solutions by open‐circuit‐potential measurements and a potentiodynamic polarization technique. The results of the potentiodynamic polarization measurements showed that the poly(aniline‐co‐o‐toluidine) coatings provided more effective corrosion protection to low‐carbon steel than the respective homopolymers. The corrosion rate depended on the feed ratio of o‐toluidine used for the synthesis of the copolymer coatings. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:1868–1878, 2007