Synthesis and characterization of monosubstituted and disubstituted poly(3,4‐propylenedioxythiophene) derivatives with high electrochromic contrast in the visible region

Monosubstituted and disubstituted 3,4‐propylenedioxythiophenes were synthesized and polymerized by both chemical and electrochemical methods. All the monomers were characterized for their molecular structures, and the polymers were characterized for their electrochemical properties. The disubstituted derivatives showed higher contrast than the corresponding monoalkyl derivatives. The highest electrochromic contrast of 89% was exhibited by a dibenzyl derivative, but the derivative was insoluble. On the other hand, the electrochemically polymerized dihexyl‐ and didodecyl‐substituted poly(3,4‐propylenedioxythiophene)s exhibited 74 and 77% electrochromic contrast, respectively, and were soluble. The molecular weights of the chemically and electrochemically synthesized polymers were analyzed by gel permeation chromatography. The chemically synthesized polymers showed higher molecular weights. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 419–428, 2005     

Synthesis and microwave absorbing properties of poly(3,4‐ethylenedioxythiophene) (PEDOT) microspheres

Poly(3,4‐ethylenedioxythiophene) (PEDOT) solid and hollow microspheres were successfully synthesized by simply adjusting the concentration of 3,4‐ethylenedioxythiophene (EDOT) and the molar ratio of EDOT to ammonium persulfate (APS) (represented by (EDOT)/(APS)), respectively. Microwave absorbing properties of PEDOT microspheres with tunable reflection loss (RL) and microwave frequency band were described in detail. The relationships between the conductivity and RL of PEDOT microspheres were also discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

High‐strength electrically conductive fibers: Functionalization of polyamide,aramid, and polyester fibers with PEDOT polymer

In this work, high‐performance fibers such as aramid (Twaron), polyamide (PA6), polyester (PET), and hybrid Twaron/PA6 fibers were transformed into electroactive fibers by coating them with conjugated polymer, poly(3,4‐ethylenedioxythiophene) (PEDOT) through vapor phase polymerization (VPP) method. The VPP is considered as an efficient technique for depositing CPs on different substrates regardless of their lower solubility in various solvents. In this paper, PEDOT‐coated high‐performance fibers were prepared under already optimized reaction conditions, and then a comparison between electrical, thermal, and mechanical properties of different fibers, before and after coating, was made. The obtained coated fibers were characterized through scanning electron microscope (SEM), thermogravimetric analysis (TGA), 2‐probe electrical resistance measurement method, and tensile testing. It was revealed that at particular reaction conditions, all high performance textile substrates were successfully converted into electroactive fibers. The voltage‐current (V‐I) characteristics showed that PEDOT‐coated polyester fibers exhibited highest conductivity value among all other substrate fibers. The active PEDOT layers on high performance fibers could behave as an antistatic coating to minimize the risks associated with static charges at work places. Also, the obtained fibers have potential to be used as smart materials for various medical, sports, and military applications.     

Synthesis of electro‐active membranes by chemical vapor deposition (CVD) process

In the past two decades, many research is being carried out on coating of textile membranes with conductive polymers. In order to functionalize the textile membranes, coating of different intrinsically conductive polymers can be applied on these membranes through appropriate coating techniques like electrochemical polymerization, wet chemical oxidation and chemical vapor deposition (CVD). Noticeably, CVD process is one of the most suitable and environment friendly technique. In this research, microporous polyester and polytetrafluoroethylene (PTFE) membranes were coated with conductive poly(3,4‐ethylenedioxythiophene) (PEDOT) by CVD process in the presence of ferric(III)chloride (FeCl₃) used as an oxidant. Polymerization of PEDOT on the surface of membranes and pore size was examined by optical microscope and scanning electron microscopy (SEM). Structural analysis investigated with ATR‐FTIR, which revealed the successful deposition of PEDOT on membranes without damaging their parent structures. The amount of PEDOT in PEDOT‐coated polyester and PTFE membranes was explored with the help of thermogravimeteric analysis. Electrical resistance values of PEDOT‐coated membranes were measured by two probe method. The effect of different electrolyte solutions such as, distilled H₂O, Na₂SO₄, HCl, and H₂SO₄ on electrical properties of produced conductive membranes was investigated after dipping for certain period of time. It was found that membranes dipped in H₂SO₄ show very low electrical resistance values, i.e. 0.85 kΩ for polyester membrane and 1.17 kΩ for PTFE membrane. The obtained PEDOT‐coated electro‐active membranes may find their possible utility in fuel cells, enzymatic fuel cells, and antistatic air filter applications. Copyright © 2014 John Wiley & Sons, Ltd.     

Organic solvent dispersion of poly(3,4‐ethylenedioxythiophene) with the use of polymeric ionic liquid

A nonaqueous dispersion of poly(3,4‐ethylenedioxythiophene) (PEDOT) was prepared with the use of polymeric ionic liquid (PIL) as a polymerization template and phase transfer medium. A detailed investigation was performed to understand the role of PIL in the course of polymerization and phase transfer reaction. On the basis of our findings from X‐ray photoelectric spectroscopy (XPS), we propose a mechanism by which the PIL leads to the nanostructured PEDOT colloids in various organic solvents and thus facilitating smoother surface morphologies of the PEDOT‐PIL films. In addition, the enhancement of charge transport was observed for PEDOT‐PIL complex when compared with PEDOT without PIL. Raman spectroscopy indicates that there is a reduced interaction between the charge carriers on the PEDOT and the counter ions bound to PIL, thus promoting charge carrier hopping rates. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6872–6879, 2008     

Synthesis and Characterization of Dendrimer‐Encapsulated Bimetallic Core‐Shell PdPt Nanoparticles

Using a successive method, PAMAM dendrimer‐encapsulated bimetallic PdPt nanoparticles have been successfully prepared with core‐shell structures (Pd@Pt DENs). Evidenced by UV‐vis spectra, high resolution transmission electron microscopy, and X‐ray energy dispersive spectroscopy (EDS), the obtained Pd@Pt DENs are monodispersed and located inside the cavity of dendrimers, and they show a different structure from monometallic Pt or Pd and alloy PdPt DENs. The core‐shell structure of Pd@Pt DENs is further confirmed by infrared measurements with carbon monoxide (IR‐CO) probe. In order to prepare Pd@Pt DENs, a required Pd/Pt ratio of 1:2 is determined for the Pt shell to cover the Pd core completely. Finally, a mechanism for the formation of Pd@Pt DENs is proposed.     

Synthesis of high performance,conductive PEDOT‐coated polyester yarns by OCVD technique

Production of high performance conductive textile yarn fibers for different electronic applications has become a prominent area of many research groups throughout the world. We have used oxidative chemical vapor deposition (OCVD) technique to coat flexible and high strength polyester yarns with conjugated polymer, poly(3,4‐ethylenedioxythiophene) (PEDOT) in presence of ferric (III) chloride (FeCl₃) oxidant. OCVD is an efficient solvent free technique used to get uniform, thin, and highly conductive polymer layers on different substrates. In this paper, PEDOT‐coated polyester (PET) yarns were prepared under specific reaction conditions, and the electrical, mechanical and thermal properties were compared to previously studied PEDOT‐coated viscose yarns. Scanning electron microscopy (SEM) and FT‐IR analysis revealed that polymerization of PEDOT on the surface of the polyester yarns has been taken place successfully and structural analysis showed that PEDOT has strong interactions with viscose yarns as compared to PET yarns. The voltage–current (V–I) characteristics showed that PET yarns are more conductive than PEDOT‐coated viscose yarns. The variation in the conductivity of PEDOT‐coated yarns and the heat generation properties during the flow of current through coated yarns for longer period of time, was studied by time–current (t–I) characteristics. Thermogravimeteric analysis (TGA) was employed to investigate the thermal properties and the amount of PEDOT in PEDOT‐coated PET yarns compared to PEDOT‐coated viscose. The effect of PEDOT coating and ferric (III) chloride concentration on the mechanical properties of coated yarns was evaluated by tensile testing. The obtained PEDOT‐coated conductive polyester yarns could be used in smart clothing for medical and military applications. Copyright © 2011 John Wiley & Sons, Ltd.     

Biosensor employing screen‐printed PEDOT:PSS for sensitive detection of phenolic compounds in water

Poly(3,4‐ethylenedioxythiophene) (PEDOT) and its derivatives are relatively new, and unique members of conducting‐polymers family. In this article, we present an approach for simple, reliable and cost‐efficient electrochemical biosensor for real‐time detection and quantification of phenolic compounds (PhCs). The PEDOT:poly(styrene sulfonate) (PSS) polymer, directly screen‐printed on the surface of the working electrode, was shown to act as an effective electrical conductor but also as an efficient redox mediator. It has also been found suitable for the reduction of quinone ions at low reducing potentials, close to 0 V versus Ag/AgCl, thus minimizing interferences due to other electroactive species present in real samples. Based on these properties, a biosensor based on tyrosinase immobilized on PEDOT:PSS‐modified electrodes was developed allowing the detection of PhCs in surface waters. The biosensor displayed very good performance in terms of sensitivity, detection limit and linear range. Assays using surface water previously spiked with bisphenol A showed that the biosensor was able to detect PhCs in real conditions with no matrix effect. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Production of highly conductive textile viscose yarns by chemical vapor deposition technique: a route to continuous process

An oxidative chemical vapor deposition (OCVD) process was used to coat flexible textile fiber (viscose) with highly conductive polymer, poly (3,4‐ethylenedioxythiophene) (PEDOT) in presence of ferric (III) chloride (FeCl₃) oxidant. OCVD is a solvent free process used to get uniform, thin, and highly conductive polymer layer on different substrates. In this paper, PEDOT coated viscose fibers, prepared under specific conditions, exhibited high conductivity 14.2 S/cm. The effects of polymerization conditions, such as polymerization time, oxidant concentration, dipping time of viscose fiber in oxidant solution, and drying time of oxidant treated viscose fiber, were carefully investigated. Scanning electron microscopy (SEM) and FT‐IR analysis revealed that polymerization of PEDOT on surface of viscose fiber has been taken place and structural analysis showed strong interactions between PEDOT and viscose fiber. Thermogravimetric analysis (TGA) was employed to investigate the amount of PEDOT in PEDOT coated viscose fiber and interaction of PEDOT with viscose fiber. The effect of PEDOT coating on the mechanical properties of the viscose fiber was evaluated by tensile strength testing of the coated fibers. The obtained PEDOT coated viscose fiber having high conductivity, could be used in smart clothing for medical and military applications, heat generation, and solar cell demonstrators. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis of Silver and Gold Nanoparticles by a Novel Electrochemical Method

Spherical silver and gold nanoparticles with narrow size distributions were conveniently synthesized in aqueous solution by a novel electrochemical method. The technological keys to the electrochemical synthesis of monodispersed metallic nanoparticles lie in the choice of an ideal stabilizer for the metallic nanoclusters and the use of a rotating platinum cathode. Poly(N‐vinylpyrrolidone) (PVP) was chosen as the stabilizer for the silver and gold clusters. PVP not only protects metallic particles from agglomeration, but also promotes metal nucleation, which tends to produce small metal particles. Using a rotating platinum cathode effectively solves the technological difficulty of rapidly transferring the (electrochemically synthesized) metallic nanoparticles from the cathode vicinity to the bulk solution, avoiding the occurrence of flocculates in the vicinity of the cathode, and ensuring the monodispersity of the particles. The particle size and particle size distribution of the silver and gold nanoparticles were improved by adding sodium dodecyl benzene sulfonate (SDBS) to the electrolyte. The electrochemically synthesized nanoparticles were characterized by TEM and UV/Vis spectroscopy.     

Polyfluorene Polyelectrolyte Nanoparticles: Synthesis of Innovative Stabilizers for Heterophase Polymerization

Polyfluorene‐bearing bromohexyl side chains are quaternized by 1‐vinylimidazole in order to attach dialkylimidazolium bromide ionic liquid (IL) species along the conjugated backbone. Subsequently, polyfluorene polyelectrolyte nanoparticles (NPs) of 40 nm in average size are created via radical cross‐linking of the pendant vinylimidazolium groups. Anion exchange from Br⁻ to BF₄⁻, PF₆⁻, and bis(trifluoromethylsulfonyl)imide anion (TFSI⁻) renders NPs adjustable dispersability in various organic solvents. The hydrophobic‐conjugated backbone and the hydrophilic dialkylimidazolium bromide IL moieties depict an amphiphilic profile, which allows the NPs to be deployed as conductive stabilizer in the emulsion polymerization of styrene. The resultant latexes are fluorescent, tunable in size and can be transferred to organic solvents without forfeiting their colloidal stability.

     

Direct and Simple Electrochemical Determination of Morphine at PEDOT Modified Pt Electrode

A simple and rapid method for morphine detection is described based on PEDOT electrode in the presence of SDS. The electrochemistry of morphine is investigated by CV, LSV and SWV. The effect of common interferences on the current response of morphine namely AA and UA is studied. The electrode is applied to the selective determination of morphine in urine samples in the linear ranges 0.3–8 µmol L^?1 and 10–60 µmol L^?1, with low detection limits of 50 and 68 nmol L^?1, respectively and recovery of 96.4 %. The application of PEDOT is realized in determination of morphine in tablets successfully.     

Electrochemical synthesis of PEDOT derivatives bearing imidazolium‐ionic liquid moieties

Novel poly(3,4‐ethylenedioxythiophene) (PEDOT) polymers bearing imidazolium‐ionic liquid moieties were synthesized by electrochemical polymerizations. For this purpose, new functional monomers were synthesized having an 3,4‐ethylenedioxythiophene (EDOT) unit and an imidazolium‐ionic liquid with different anions such as tetrafluoroborate (BF), bis(trifluoromethane)sulfonimide ((CF₃SO₂)₂N^?), and hexafluorophosphate (PF). Next, polymer films were obtained by electrochemical synthesis in dicholoromethane solutions. Obtained polymers were characterized, revealing the characteristics of PEDOT in terms of electrochemical and spectroelectrochemical properties, FTIR, ¹H NMR, and AFM microscopy. Interestingly, the hydrophobic character of electropolymerized films could be modified depending on the anion type. The hydrophobicity followed the trend PF > (CF₃SO₂)₂N^? > BF > pure PEDOT as determined by water contact angle measurements. Furthermore, the polymers could be dissolved in a range of polar organic solvents such as dimethylformamide, propylene carbonate, and dimethyl sulfoxide making these polymers interesting candidates for wet processing methods. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3010–3021, 2009     

Poly(3,4‐ethylenedioxythiophene) (PEDOT)‐Coated MWCNTs Tethered to Conducting Substrates: Facile Electrochemistry and Enhanced Coloring Efficiency

Composite films of poly(3,4‐ethylenedioxythiophene) (PEDOT)‐coated over functionalized multiwalled coiled and linear carbon nanotubes (CNTs) have been fabricated by a simple oxidative electropolymerization route. The nanotubular morphology of the polymer–CNT composite is responsible for the lower charge transfer impedance, lower internal resistance, and superior capacitive response in comparison to that shown by the control PEDOT film doped by trifluoromethanesulfonate ions. This facile electrochemistry exhibited by the PEDOT–CNT composite film ensues in a remarkably high coloration efficiency of 367 cm² · C⁻¹ at 550 nm, hitherto unrealized for PEDOT; thus demonstrating the huge potential the PEDOT–CNT composite film has as cathode for the entire spectrum of electrochromic devices.

     

Well‐Defined SiO2@P(EtOx‐stat‐EI) Core–Shell Hybrid Nanoparticles via Sol‐Gel Processes

Positively charged nanoparticles (NPs) are very interesting for biomedical and pharmaceutical applications, such as nonviral gene delivery. Here, the synthesis of SiO₂ nanoparticles with a covalently grafted poly(2‐ethyl‐2‐oxazoline) (PEtOx) shell (SiO₂@PEtOx) is presented. PEtOx with a degree of polymerization of 20 and 38 is synthesized via microwave supported cationic ring‐opening polymerization and subsequently end‐functionalized with a triethoxysilyl linker for subsequent grafting to silica particles with hydrodynamic radii of 7, 31, and 152 nm. The resulting SiO₂@PEtOx particles are characterized by using dynamic light scattering (DLS), transmission electron microscopy (TEM, cryoTEM), and scanning electron microscopy (SEM) to determine changes in particle size. Thermal gravimetrical analysis is used to quantify the amount of polymer on the silica surface. Subsequent in situ transformation of SiO₂@PEtOx particles into SiO₂@P(EtOx‐stat‐EI) (poly(2‐ethyl‐2‐oxazoline‐stat‐ethylene imine) grafted silica particles) under acidic conditions inverts the surface charge from negative to positive according to ζ‐potential measurements. The P(EtOx‐stat‐EI) shell could be used for the deposition of Au NP afterward.

     

Low Bandgap Semiconducting Copolymer Nanoparticles by Suzuki Cross‐Coupling Polymerization in Alcoholic Dispersed Media

The synthesis and formulation of organic semiconductors for the emerging technology of organic electronics requires the use of preparative methods and solvents being environment friendly. Today most of the active layer materials for the organic photovoltaic devices and modules are using chlorinated solvents, which are toxic and hazardous. In this work, the synthesis of poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5‐(4,7‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole] (PCDTBT) in propan‐1‐ol is presented as the dispersant continuous phase in the presence of poly(vinylpyrrolidone) used as stabilizer. Suzuki–Miyaura polycondensation of 9‐(9‐heptadecanyl)‐9H‐carbazole‐2,7‐diboronic acid bis(pinacol) ester and 4,7‐bis(2‐bromo‐5‐thienyl)‐2,1,3‐benzothiadiazole in alcohol dispersion yields colloidally stable nanoparticles of PCDTBT with particles size of 330–1300 nm, depending on the stabilizer concentration. Other reaction parameters are also discussed such as the amount of base or Pd catalyst.

     

Synthesis of Poly(3,4‐ethylenedioxythiophene) latexes using poly(N‐vinylpyrrolidone)‐based copolymers as reactive stabilizers

The synthesis by oxidative polymerization of well‐defined poly(3,4‐ethylenedioxythiophene) (PEDOT) nano‐objects in the presence of modified and unmodified poly(N‐vinylpyrrolidone)‐based copolymers used as stabilizers in aqueous media is reported. Ammonium persulfate or a mixture of ammonium persulfate with CuCl₂ or CuBr₂ was used as oxidants. The effects of several parameters such as the molar mass and the concentration of the stabilizer as well as the nature of the oxidants on the size, morphology, and the conductivity of the PEDOT particles have been investigated. The distribution of the reactive moieties along the copolymer stabilizer backbone was shown to be crucial to get well‐defined PEDOT nano‐objects. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3841–3855, 2010     

Efficient enhancement of the thermoelectric performance of vapor phase polymerized poly(3,4‐ethylenedioxythiophene) films with poly(ethyleneimine)

Tuning the molecular rearrangement and oxidation level has been proven to be effective strategies for optimizing the thermoelectric (TE) performance of PEDOT. It is difficult to achieve these effects simultaneously via a one‐step process, however. In this work, we combined vapor phase polymerization (VPP) and H₂SO₄ post‐treatment to obtain a highly conductive PEDOT film. A novel strategy using polyethylenemine (PEI) as an effective reducing agent was employed to enhance the thermopower of the PEDOT film. Grazing‐Incidence Wide‐Angle X‐ray Scattering analysis and the changes in the oxidation level allow us to elucidate the role of PEI and its transport mechanism. It is demonstrated that the thermopower of well‐ordered crystallites in the PEDOT film significantly increases more than five times (from 11 to 59 μV K^?1) by the PEI‐DMF solution immersion process, while the electrical conductivity is maintained at 100 S cm^?1. The promising method connecting VPP, H₂SO₄, and PEI shows great potential for effectively tuning the thermopower of organic TE materials. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 257–265