| 1. |
- Ajjan, Fátima, 1986-, et al.
(författare)
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Doped Conjugated Polymer Enclosing a Redox Polymer : Wiring Polyquinones with Poly(3,4‐Ethylenedioxythiophene)
- 2020
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Ingår i: Advanced Energy and Sustainability Research. - : John Wiley & Sons. - 2699-9412. ; 1:2
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Tidskriftsartikel (refereegranskat)abstract
- The mass implementation of renewable energies is limited by the absence of efficient and affordable technology to store electrical energy. Thus, the development of new materials is needed to improve the performance of actual devices such as batteries or supercapacitors. Herein, the facile consecutive chemically oxidative polymerization of poly(1-amino-5-chloroanthraquinone) (PACA) and poly(3,4-ethylenedioxythiophene (PEDOT) resulting in a water dispersible material PACA-PEDOT is shown. The water-based slurry made of PACA-PEDOT nanoparticles can be processed as film coated in ambient atmosphere, a critical feature for scaling up the electrode manufacturing. The novel redox polymer electrode is a nanocomposite that withstands rapid charging (16 A g−1) and delivers high power (5000 W kg−1). At lower current density its storage capacity is high (198 mAh g−1) and displays improved cycling stability (60% after 5000 cycles). Its great electrochemical performance results from the combination of the redox reversibility of the quinone groups in PACA that allows a high amount of charge storage via Faradaic reactions and the high electronic conductivity of PEDOT to access to the redox-active sites. These promising results demonstrate the potential of PACA-PEDOT to make easily organic electrodes from a water-coating process, without toxic metals, and operating in non-flammable aqueous electrolyte for large scale pseudocapacitors.
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| 2. |
- Gabrielsson, Roger
(författare)
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Electroactive Conjugated Polyelectrolytes Based on EDOT From Synthesis to Organic Electronics
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Conjugated polyelectrolytes (CP) show interesting electrical and optical properties for organic electronics as well as for life science applications. Their possibilities of supramolecular assembly with nanowire like misfolded proteins, amyloids, as well as synthetic polypeptides or DNA forming conducting nano composites is highly interesting as being a truly bottom up approach for fabrication of OLEDs, photovoltaic’s as well as logic devices.A special class of CPs is that of electroactive cojugated polymers (ECPs), which, due to their structure, will exhibits a unique combination of properties, including the following; electrically conducting, ability to store an electric charge and ability to exchange ions. The positive or negative excess charge can be introduced into the conjugated polymer by means of chemical or electrochemical oxidation/reduction (a process called doping) following the polymerization reaction. In order to preserve overall electroneutrality of the polymer during introduction of excess charge, ionexhange processes occurs between the polymer phase and the surrounding electrolyte solution. This charge/discharge process can be utilized for application such as; pseudo super capacitors (energy storage through oxidation/reduction processes), electro mechanical actuators (convert electrical energy to mechanical energy) and sensors (converts a chemical signal to electrical conductivity).In this thesis we describes the synthetic challenges with ECPs for applications vide supra. These mostly relates to solubility, ionic functionalization, conductivity and macromolecular properties such as size and shape of the ECPs. The key requirement in the synthesis of ECPs is that the conjugated nature of the monomer is conserved in the synthesis process and that insertion of excess charge (doping) can be obtained. This limits both the choice of monomer and the choice of polymerization process. Monomers of great complexity have been synthesized with this careful goal in mind. Furthermore, the development of novel monomers must also target the appropriate functionality for polymerization. As such, most ECP monomers are electron-rich molecules with pendant groups containing pyrroles, thiophenes, or 3,4-ethylenedioxythiophenes. These three well known ECP monomers are excellent additions to conjugated systems as they typically enable electrochemical polymerization and direct the polymerizations toward linear polymers with good stability towards doping.The first topic of this thesis we demonstrate how we can obtain water soluble ECPs with good electrical conductivity by controlling the polymerization techniques and proper ionic functionalization of the monomer. We also show how these polymers can be incorporated by self-assembly with biomolecular templates, such as, DNA and amyloid fibrils, thus generating novel electrically conductive nanowires.The second topics of this thesis demonstrate how hydrogels of ECPs can be used as bioand charge storage materials, were we demonstrate electronically controlled cell release for biology applications. Both applications are based on ECPs ability to ionexhange processes during electrochemical redox reactions. As well as ions, solvent and other neutral molecules may enter the film during charge/discharge processes. This cause a swelling or shrinking of the ECP films and the expansion and contraction of the polymer network in conjugation with the sorption/desorption of solvent molecules and ions can be described in terms of mechanical work.In the first case we were able to synthesize a water soluble ECP with high amphiphilic character. The polymer was immobilized onto a flexible electrode, suitable for cell growth and subjected to a cell growth media. When the desired cell layer was formed we applied a potential to the flexible electrode. This resulted in that the mechanical work of the immobilized ECP during the applied potential overcame the week adhesive forces to the flexible electrode, which resulted in super swelling and disintegration of the ICP and the cell layer could be harvested.In the second case the possibilities of using synthetically modified ECPs as a dopant during electropolymerization of another ECP monomer to obtain a polymer integrated network with high charge density and good charge transport properties. We demonstrate how this polymer network can be used as porous electrodes suitable for supercapacitors.
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| 3. |
- Gabrielsson, Roger H, et al.
(författare)
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Hydrogels of polypyrrole and self doped PEDOT for porous electrodes and supercapacitors
- 2012
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this work is to extend the knowledge of the mechanism of electropolymerization of pyrrole and PEDOT-S by means of in situ electrochemical quartz microbalance with dissipation studies (EQCM-D), which allow us to evaluate the chemical and physical processes during electrochemical deposition of these conductive polymer composites. Meanwhile, the relationship between the morphology of the films and the mechanism of the electropolymerization of pyrrole in presence of PEDOT-S will be discussed. The resulting material is electroactive, black and conducting. This material is a polymer composite where doped polypyrrole chains are found in an environment of doped PEDOT-S chains. They can be identified through the cyclic voltammetry studies of the composite, through element composition and through their optical signatures in electrochromism. The composite has properties suitable for a supercapacitor electrode, and capacitance of up to 650 F/g has been obtained.
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| 4. |
- Hamedi, Mahiar, et al.
(författare)
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Electronic Polymers and DNA Self-assembled in Nanowire Transistors
- 2013
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Ingår i: Small. - : Wiley-VCH Verlag Berlin. - 1613-6810 .- 1613-6829. ; 9:3, s. 363-368
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Tidskriftsartikel (refereegranskat)abstract
- In this study the fully acidic form of PEDOT-S was used for the purpose of self-assembly onto DNA. We have previously shown that PEDOT-S is a short polymer that is self-doped with !1/3 of the sulfonate side groups acting as the self-doping sites (see supporting info.). The remaining sulfonate groups contribute to a net anionic charge, and a water-soluble polymer, with an intrinsic bulk conductivity of around 30 S/cm. It has been shown that PEDOT-S can bind to oppositely charged cationic amyloid protein structures in water and form conducting nano fibrillar networks, and it has also been shown to form hybrid structures with synthetic peptides, and gold nanoparticles.
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| 5. |
- Musumeci, Chiara, et al.
(författare)
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Organic electrochemical transistors from supramolecular complexes of conjugated polyelectrolyte PEDOTS
- 2019
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Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 7:10, s. 2987-2993
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Tidskriftsartikel (refereegranskat)abstract
- Counterion exchange strategies are used to modify the hydrophilic character of the self-doped conjugated polyelectrolyte PEDOTS. The supramolecular complexes, soluble in organic solvents, are suitable to fabricate finely performing thin active layers in organic electrochemical transistors (OECTs). We demonstrate that ionic transport in these PEDOTS based complexes, thus their performance in OECT devices, is governed by a delicate balance among degree of doping, wettability and porosity, which can be controlled by a precise tuning of the polyelectrolyte/hydrophobic counterion ratio. We also show that the device operation can be modulated by varying the composition of the aqueous electrolyte in a range compatible with biological processes, making these materials suitable candidates to be interfaced with living cells.
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| 6. |
- Nagaraju, D. H., et al.
(författare)
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Charge Storage Capacity of Renewable Biopolymer/Conjugated Polymer Interpenetrating Networks Enhanced by Electroactive Dopants
- 2014
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Ingår i: Advanced Energy Materials. - : Wiley-VCH Verlag. - 1614-6832 .- 1614-6840. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- Renewable materials are requested for large scale electrical storage, a coming necessity with the growth of intermittent solar and wind renewable electricity generation. Biopolymers are a source of inexpensive materials, in particular through the use of black liquor from paper production, a waste product. Interpenetrating networks of the biopolymer lignosulfonate (Lig) and conjugated polymer polypyrrole (Ppy) are synthesized by galvanostatic polymerization from pyrrole/lignosulfonate mixture in acidic aqueous electrolyte. Methoxy and phenolic functional group present in the non-conducting lignosulfonate are converted to quinone groups. The redox chemistry of quinones is used for charge storage, along with charge storage in polypyrrole. A large variation of the electrochemical activity between lignosulfonates obtained from different sources is observed. The charge storage capacities are significantly enhanced by also including another electroactive dopant, anthraquinone sulfonate (AQS). AQS redox peaks act as an internal reference (standard) to probe the redox electrochemistry of Lig. The synthesized Ppy(Lig) and Ppy(Lig-AQS) electrodes are characterized by cyclic voltammetry, galvanostatic charge-discharge cycling, electrochemical quartz crystal microbalance, and atomic force microscopy.
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| 7. |
- Sobkowiak, Marek, et al.
(författare)
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Amperometric detection of iron (III) on electroconductive hydrogel based on polypyrrole and alkoxysulfonated poly(3,4-ethylenedioxythiophene) (PEDOT-S)
- 2014
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Ingår i: Synthetic metals. - : Elsevier. - 0379-6779 .- 1879-3290. ; 194, s. 170-175
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Tidskriftsartikel (refereegranskat)abstract
- A polymeric conducting hydrogel of autopolymerized polypyrrole (PPY) and poly(4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl-methoxy)-1-butanesulfonic acid (PEDOT-S) cast-deposited on a glassy carbon electrode is demonstrated to be an efficient electrocatalyst for the fairly irreversible, and often irreproducible, reduction of Fe(Ill) at the bare substrate. Sensitive amperometric monitoring of Fe(III) is then possible without the need for oxygen removal at the fairly positive polarization potential of 0.3 V vs. Ag/AgCl in acidic electrolyte (0.1 M HClO4). The sensor shows a linear current response over a concentration range exceeding two orders of magnitude (2.5-500 mu M, R-2 = 0.9998). The detection limit (3 sigma) was estimated to be 0.8 mu M, and the sensitivity factor was 0.28 mu A mu M cm(-2), which is approximately 23 times higher than for the unmodified electrode under the same experimental conditions.
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| 8. |
- Sobkowiak, Marek, et al.
(författare)
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Electrochemistry and Ion Sensing Properties of Conducting Hydrogel Layers Based on Polypyrrole and Alkoxysulfonated Poly(3,4-ethylenedioxythiophene) (PEDOT-S)
- 2014
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Ingår i: Electroanalysis. - : Wiley-VCH Verlag. - 1040-0397 .- 1521-4109. ; 26:4, s. 739-747
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Tidskriftsartikel (refereegranskat)abstract
- Acidic aqueous solutions containing pyrrole and alkoxysulfonated PEDOT derivative (PEDOT-S) were found to undergo polymerization in the absence of an external oxidizing agent. The product was a nearly black-colored conducting hydrogel that after separation could be dispersed in water or acetone. The suspensions could be used to deposit cast films on a polycrystalline gold electrode. The polymer modified electrode showed a nearly Nernstian potentiometric response to Ag+ cations in the concentration range of 10(-5)-10(-1)M with the slope of 54mV/decade. The response was specific to Ag+ compared to a series of alkali and transition-metal cations (pK(Ag/M)greater than3.7).
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| 9. |
- Zeglio, Erica, et al.
(författare)
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Conjugated Polyelectrolyte Blend as Photonic Probe of Biomembrane Organization
- 2016
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Ingår i: ChemistrySelect. - : John Wiley & Sons. - 2365-6549. ; 1:14, s. 4340-4344
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Tidskriftsartikel (refereegranskat)abstract
- In the following report, a conjugated polyelectrolyte (CPE) blend has been introduced for the first time as a fluorescent probe of membrane organization. Insertion of the blend into the lipid double layer has been rendered possible through formation of a hydrophobic complex by counterion exchange. Changes in membrane physical state from liquid-disordered (Ldis) to liquid-ordered (Lord), and to solid-ordered (Sord) result in red shifts of blend excitation (up to Δλex=+90 nm) and emission (up to Δλnm=+37 nm) maxima attributable to backbone planarization of CPEs. We found that blend stoichiometry can be adjusted to attain the best interplay among single polyelectrolytes properties, such as sensitivity and luminescence. The resulting probes therefore allow a bimodal detection of membrane physical state: changes in absorption permit a direct visualization of membrane organization, while variations in emission spectra demonstrate that CPE-blends are a promising probes that can be used for imaging applications.
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| 10. |
- Zeglio, Erica, et al.
(författare)
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Conjugated Polyelectrolyte Blends for Electrochromic and Electrochemical Transistor Devices
- 2015
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Ingår i: Chemistry of Materials. - : AMER CHEMICAL SOC. - 0897-4756 .- 1520-5002. ; 27:18, s. 6385-6393
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Tidskriftsartikel (refereegranskat)abstract
- Two self-doped conjugated polyelectrolytes, having semiconducting and metallic behaviors, respectively, have been blended from aqueous solutions in order to produce materials with enhanced optical and electrical properties. The intimate blend of two anionic conjugated polyelectrolytes combine the electrical and optical properties of these, and can be tuned by blend stoichiometry. In situ conductance measurements have been done during doping of the blends, while UV vis and EPR spectroelectrochemistry allowed the study of the nature of the involved redox species. We have constructed an accumulation/depletion mode organic electrochemical transistor whose characteristics can be tuned by balancing the stoichiometry of the active material.
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