Showing papers on "Conductive polymer published in 2017"
TL;DR: In this paper, an electrostatic assembly approach for fabricating highly conductive MXene@polystyrene nanocomposites by electrostatic assembling of negative MXene nanosheets on positive polystyrene microspheres is demonstrated, followed by compression molding.
Abstract: Highly conductive polymer nanocomposites are greatly desired for electromagnetic interference (EMI) shielding applications. Although transition metal carbide/carbonitride (MXene) has shown its huge potential for producing highly conductive films and bulk materials, it still remains a great challenge to fabricate extremely conductive polymer nanocomposites with outstanding EMI shielding performance at minimal amounts of MXenes. Herein, an electrostatic assembly approach for fabricating highly conductive MXene@polystyrene nanocomposites by electrostatic assembling of negative MXene nanosheets on positive polystyrene microspheres is demonstrated, followed by compression molding. Thanks to the high conductivity of MXenes and their highly efficient conducting network within polystyrene matrix, the resultant nanocomposites exhibit not only a low percolation threshold of 0.26 vol% but also a superb conductivity of 1081 S m−1 and an outstanding EMI shielding performance of >54 dB over the whole X-band with a maximum of 62 dB at the low MXene loading of 1.90 vol%, which are among the best performances for electrically conductive polymer nanocomposites by far. Moreover, the same nanocomposite has a highly enhanced storage modulus, 54% and 56% higher than those of neat polystyrene and conventional MXene@polystyrene nanocomposite, respectively. This work provides a novel methodology to produce highly conductive polymer nanocomposites for highly efficient EMI shielding applications.
562 citations
TL;DR: This review explores some intriguing applications of polyaniline nanofibers, as well as the advantages and remaining challenges in developing better products using polyAniline in this new morphology.
Abstract: Polyaniline is a conducting polymer with incredible promise, but it has had limited use due to poor reaction control and processability associated with conventional morphologies. Polyaniline nanofibers, on the other hand, have demonstrated, through manufacturing techniques discovered during the past decade, increased processability, higher surface area, and improved consistency and stability in aqueous dispersions, which are finally allowing for expanded commercial development of this promising polymer. This review explores some intriguing applications of polyaniline nanofibers, as well as the advantages and remaining challenges in developing better products using polyaniline in this new morphology.
442 citations
TL;DR: In this paper, a desktop 3D printer was used to print CNT and graphene-based polybutylene terephthalate (PBT) structures for electrical conductivity and mechanical stability.
407 citations
TL;DR: In this article, the authors analyse the electrical conductivity and Seebeck coefficient together and determine that most polymers have s = 3 and thermally activated conductivity, whereas s = 1 and itinerant conductivity is typically found in crystalline semiconductors and metals.
Abstract: The growing technological importance of conducting polymers makes the fundamental understanding of their charge transport extremely important for materials and process design. Various hopping and mobility edge transport mechanisms have been proposed, but their experimental verification is limited to poor conductors. Now that advanced organic and polymer semiconductors have shown high conductivity approaching that of metals, the transport mechanism should be discernible by modelling the transport like a semiconductor with a transport edge and a transport parameter s. Here we analyse the electrical conductivity and Seebeck coefficient together and determine that most polymers (except possibly PEDOT:tosylate) have s = 3 and thermally activated conductivity, whereas s = 1 and itinerant conductivity is typically found in crystalline semiconductors and metals. The different transport in polymers may result from the percolation of charge carriers from conducting ordered regions through poorly conducting disordered regions, consistent with what has been expected from structural studies.
383 citations
TL;DR: A flexible supercapacitor device based on ZIF-PPy networks shows an outstanding areal capacitance of 225.8 mF cm-2, which is far above other MOFs-basedsupercapacitors reported up to date, confirming the significance of in situ synthetic chemistry as well as the importance of hybrid materials on the nanoscale.
Abstract: Metal–organic frameworks (MOFs) with high porosity and a regular porous structure have emerged as a promising electrode material for supercapacitors, but their poor electrical conductivity limits their utilization efficiency and capacitive performance. To increase the overall electrical conductivity as well as the efficiency of MOF particles, three-dimensional networked MOFs are developed via using preprepared conductive polypyrrole (PPy) tubes as the support for in situ growth of MOF particles. As a result, the highly conductive PPy tubes that run through the MOF particles not only increase the electron transfer between MOF particles and maintain the high effective porosity of the MOFs but also endow the MOFs with flexibility. Promoted by such elaborately designed MOF–PPy networks, the specific capacitance of MOF particles has been increased from 99.2 F g–1 for pristine zeolitic imidazolate framework (ZIF)-67 to 597.6 F g–1 for ZIF–PPy networks, indicating the importance of the design of the ZIF–PPy cont...
337 citations
TL;DR: In this paper, the authors highlight recent major progress in the development of organic semiconductors as electron transport n-channel materials in organic field effect transistors (OFETs) and discuss three types of materials: small molecules, polymers, and n-doped small molecules and polymers.
Abstract: This review highlights recent major progress in the development of organic semiconductors as electron transport n-channel materials in organic field effect transistors (OFETs). Three types of materials are discussed: (1) small molecules, (2) polymers, and (3) n-doped small molecules and polymers. Much effort has been made in the modification of known building blocks, development of novel building blocks, and optimization of materials processing and device structures. These efforts have resulted in the achievement of record high electron mobilities for both small molecules (12.6 cm2 V−1 s−1) and polymers (14.9 cm2 V−1 s−1), which are approaching the highest hole mobilities achieved by p-type small molecules and polymers so far. In addition, n-doping of ambipolar and p-type organic semiconductors has proven to be an efficient approach to obtaining a greater number of n-type organic semiconductors. However, it is found that n-type organic semiconductors, in general, still lag behind p-type organic semiconductors in terms of carrier mobility and air stability. Further exploration of new building blocks for making novel materials and optimization of processing conditions and device structures are needed to improve the performance, particularly air stability.
324 citations
TL;DR: This Account reviews the recent progress on the synthesis, properties, and novel applications of dopant cross-linked CPGs and describes the synthetic strategies, in which molecules with multiple functional groups are adopted asCross-linkers to cross-link conductive polymer chains into a 3D molecular network.
Abstract: ConspectusConductive polymers have attracted significant interest over the past few decades because they synergize the advantageous features of conventional polymeric materials and organic conductors. With rationally designed nanostructures, conductive polymers can further exhibit exceptional mechanical, electrical, and optical properties because of their confined dimensions at the nanoscale level. Among various nanostructured conductive polymers, conductive polymer gels (CPGs) with synthetically tunable hierarchical 3D network structures show great potential for a wide range of applications, such as bioelectronics, and energy storage/conversion devices owing to their structural features. CPGs retain the properties of nanosized conductive polymers during the assembly of the nanobuilding blocks into a monolithic macroscopic structure while generating structure-derived features from the highly cross-linked network.In this Account, we review our recent progress on the synthesis, properties, and novel applica...
306 citations
TL;DR: In this article, a novel and facile method is reported to significantly enhance the thermoelectric (TE) property of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films through sequential post-treatments with common acids and bases.
Abstract: Thermoelectric (TE) materials are important for the sustainable development because they enable the direct harvesting of low-quality heat into electricity. Among them, conducting polymers have attracted great attention arising from their advantages, such as flexibility, nontoxicity, easy availability, and intrinsically low thermal conductivity. In this work, a novel and facile method is reported to significantly enhance the TE property of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films through sequential post-treatments with common acids and bases. Compared with the as-prepared PEDOT:PSS, both the Seebeck coefficients and electrical conductivities can be remarkably enhanced after the treatments. The oxidation level, which significantly impacts the TE property of the PEDOT:PSS films, can also be well tuned by controlling the experimental conditions during the base treatment. The optimal PEDOT:PSS films can have a Seebeck coefficient of 39.2 µV K−1 and a conductivity of 2170 S cm−1 at room temperature, and the corresponding power factor is 334 µW (m−1 K−2). The enhancement in the TE properties is attributed to the synergetic effect of high charge mobility by the acid treatment and the optimal oxidation level tuned by the base treatment.
295 citations
TL;DR: In this article, a review with 347 references summarizes advances in the preparation and functionalization of graphene nanocomposites for the application of electrochemical sensors and biosensors, and a concluding section covers current challenges and perspectives of graphene and GO based (bio)sensing.
Abstract: Functionalized nanocomposites based on various type of graphene nanomaterials including graphene, graphene oxides (GOs), and doped graphene (oxides) are widely used as materials for various sensors that can display high sensitivity, selectivity and stability. This review with 347 references summarizes advances in the preparation and functionalization of graphene nanocomposites for the application of electrochemical sensors and biosensors. Following a general introduction into the field, the article is divided into subsections on (a) the synthesis and functionalization of nanocomposites (made from graphene, various kinds of GOs, heteroatom-doped GOs), (b) on methods for functionalization of composites (with other carbon nanomaterials, metal nanoparticles, metal oxide and metal sulfide nanoparticles), (c) on functionalization with inorganic materials including polyoxometalates, hexacyanoferrates, minerals), (d) on functionalization with organic materials such as amino acids, surfactants, organic dyes, ionic liquids, macrocycles (including cyclodextrins, crown ethers and calixarenes), and (e) on functionalization with organometallics and with various other organic compounds, (f) on functionalizations with polymers such as conventional polymers, polyelectrolytes, conducting polymers, molecularly imprinted polymers, (g) on functionalization with biomolecules including proteins and nucleic acids. Other subsections cover flexible graphene and GO based nanocomposites and 3D composites. Application of graphene and GO nanocomposites are then covered in a in large section that comprises electrochemical sensors and biosensors (based on voltammetry, amperometry, potentiometry, impedimetry, electrochemiluminescence, photoelectrochemistry, field effect transistors, electrochemical immunosensors) with specific subsections on gas sensors, enzymatic biosensors and gene sensors. A concluding section covers current challenges and perspectives of graphene and GO based (bio)sensing.
286 citations
TL;DR: A highly conductive and mechanically strong porous fiber is prepared by drying PEDOT:PSS hydrogel fiber to fabricate a current-collector-free solid-state flexible supercapacitor, promising for the application as wearable energy-storage devices.
Abstract: A poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) hydrogel is prepared by thermal treatment of a commercial PEDOT:PSS (PH1000) suspension in 01 mol L-1 sulfuric acid followed by partially removing its PSS component with concentrated sulfuric acid This hydrogel has a low solid content of 4% (by weight) and an extremely high conductivity of 880 S m-1 It can be fabricated into different shapes such as films, fibers, and columns with arbitrary sizes for practical applications A highly conductive and mechanically strong porous fiber is prepared by drying PEDOT:PSS hydrogel fiber to fabricate a current-collector-free solid-state flexible supercapacitor This fiber supercapacitor delivers a volumetric capacitance as high as 202 F cm-3 at 054 A cm-3 with an extraordinary high-rate performance It also shows excellent electrochemical stability and high flexibility, promising for the application as wearable energy-storage devices
261 citations
TL;DR: In this article, the authors summarized the latest contributions and progress in aqueous/non-aqueous faradaic electrode materials including conductive polymers and/or transition metal oxides/sulfides/nitrides/carbides, the operating principles, system design/engineering, and rational optimization of all-pseudocapacitive ASCs.
Abstract: Recently, asymmetric supercapacitors (ASCs) have attracted extensive research interest worldwide for their potential application in emerging energy-related fields. The smart integration of high overall cell operating voltage and large capacitance can be realized in all-pseudocapacitive-electrode-materials-based ASCs. This innovative all-pseudocapacitive-asymmetric design provides a fascinating way to obtain high-energy-density devices with high power rates and also holds huge potential to bridge the gap between dielectric capacitors and rechargeable batteries. In the present review, we mainly summarized the latest contributions and progress in aqueous/non-aqueous faradaic electrode materials including conductive polymers and/or transition metal oxides/sulfides/nitrides/carbides, the operating principles, system design/engineering, and the rational optimization of all-pseudocapacitive ASCs. The intrinsic advantages and disadvantages of these unique ASCs have been elaborately discussed and comparatively evaluated. Finally, some future trends, prospects, and challenges, especially in rate capability and cycling stability, have been presented for advanced next-generation ASCs.
TL;DR: In this paper, a conductive electrochemical sensor, UiO-66-NH2@PANI, was successfully prepared by polymerizing the conductive polyaniline (PANI) polymer around the metal-organic framework Ui
Abstract: In this work, a conductive electrochemical sensor, UiO-66-NH2@PANI, was successfully prepared by polymerizing the conductive polyaniline (PANI) polymer around the metal–organic framework UiO-66-NH2. Fourier transform infrared spectra, X-ray diffraction patterns, and X-ray photoelectron spectral data support the formation of UiO-66-NH2@PANI. Additionally, scanning and transmission electron microscopy investigations confirm that PANI uniformly coated the surface of UiO-66-NH2. The resultant material was applied to construct a novel electrochemical sensor for the reliable detection of cadmium ions due to the chelation mechanism between metal cations and amine groups. Under optimized conditions, a linear detection of Cd2+ concentration range of 0.5–600 μg L−1 was repeatable with a 0.3 μg L−1 lowest level detection limit. Little to no interference effects from other co-existing ions allow the sensor to work in varying environments for practical application. This method of coating metal–organic frameworks may show utility for constructing highly sensitive electrochemical sensors for the detection of heavy metal ions and more.
TL;DR: The field of organic electronics has been heavily impacted by the discovery and development of π-conjugated conducting polymers as mentioned in this paper, and polythiophene and its derivatives have been widely investigated computationally and experimentally for use in electronic devices such as light-emitting diodes, water purification devices, hydrogen storage, and biosensors.
Abstract: The field of organic electronics has been heavily impacted by the discovery and development of π-conjugated conducting polymers. These polymers show great potential for integration into future optical and electronic devices due to their capacity to transition between semiconducting and conducting states as well as the ability to alter mechanical properties by controlled doping, chemical modification, and stacking or creating composites with other materials. Among π-conjugated polymers, polythiophene and its derivatives has been one of the most extensively studied and is widely investigated computationally and experimentally for use in electronic devices such as light-emitting diodes, water purification devices, hydrogen storage, and biosensors. Various theoretical modeling studies of polythiophene ranging from an oligothiophene approach to infinite chain lengths (periodic boundary conditions) have been undertaken to study a variety of electronic and structural properties of these polymers. In this review,...
TL;DR: Poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is the most studied and explored mixed ion-electron conducting polymer system as mentioned in this paper.
Abstract: Poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is the most studied and explored mixed ion-electron conducting polymer system PEDOT: PSS is commonly included as an electroactiv
TL;DR: In this paper, the most commonly adopted preparation strategies for conductive polymer nanocomposites are summarized, which mainly include direct mixing/blending (ex situ) and in situ methods (in situ polymerization or nanostructure synthesis).
Abstract: As a unique group of advanced polymer-based materials, conductive polymer nanocomposites combining the flexibility and/or conductivity of the polymer with the distinct properties of nanofillers have found many intriguing applications in various modern devices. This review provides a concise yet inclusive introduction to the concept of conductive polymer nanocomposites backed by some modern technologically advanced devices resulting from the advances made in this area. The most commonly adopted preparation strategies are first summarized, which mainly include direct mixing/blending (ex situ) and in situ methods (in situ polymerization or nanostructure synthesis). Selective examples of device applications are then detailed including organic light emission diodes (OLEDs), photovoltaics (PV), electrochromic devices (ECDs) and others. Lastly, concluding remarks and future perspectives are given for conductive polymer nanocomposites as viable electronic integration tools.
TL;DR: A highly transparent and stretchable supercapacitor is demonstrated by developing Ag/Au/Polypyrrole core-shell nanowire networks as electrode by coating the surface of Ag NWs with a thin layer of gold, which provide higher redox potential than the electropolymerizable monomer.
Abstract: Transparent and stretchable energy storage devices have attracted significant interest due to their potential to be applied to biocompatible and wearable electronics. Supercapacitors that use the reversible faradaic redox reaction of conducting polymer have a higher specific capacitance as compared with electrical double-layer capacitors. Typically, the conducting polymer electrode is fabricated through direct electropolymerization on the current collector. However, no research have been conducted on metal nanowires as current collectors for the direct electropolymerization, even though the metal nanowire network structure has proven to be superior as a transparent, flexible, and stretchable electrode platform because the conducting polymer's redox potential for polymerization is higher than that of widely studied metal nanowires such as silver and copper. In this study, we demonstrated a highly transparent and stretchable supercapacitor by developing Ag/Au/Polypyrrole core-shell nanowire networks as electrode by coating the surface of Ag NWs with a thin layer of gold, which provide higher redox potential than the electropolymerizable monomer. The Ag/Au/Polypyrrole core-shell nanowire networks demonstrated superior mechanical stability under various mechanical bending and stretching. In addition, proposed supercapacitors showed fine optical transmittance together with fivefold improved areal capacitance compared to pristine Ag/Au core-shell nanowire mesh-based supercapacitors.
TL;DR: Polypyrrole-coated Shewanella oneidensis MR-1 is employed as an anode in microbial fuel cells (MFCs) and it is found that not only direct contact-based extracellular electron transfer is dramatically enhanced, but also the viability of bacterial cells in MFCs is improved.
Abstract: Coating individual bacterial cells with conjugated polymers to endow them with more functionalities is highly desirable. Here, we developed an in situ polymerization method to coat polypyrrole on the surface of individual Shewanella oneidensis MR-1, Escherichia coli, Ochrobacterium anthropic or Streptococcus thermophilus. All of these as-coated cells from different bacterial species displayed enhanced conductivities without affecting viability, suggesting the generality of our coating method. Because of their excellent conductivity, we employed polypyrrole-coated Shewanella oneidensis MR-1 as an anode in microbial fuel cells (MFCs) and found that not only direct contact-based extracellular electron transfer is dramatically enhanced, but also the viability of bacterial cells in MFCs is improved. Our results indicate that coating individual bacteria with conjugated polymers could be a promising strategy to enhance their performance or enrich them with more functionalities.
TL;DR: By exploiting the additional benefits of high transparency and solution-processability of PEDOT:PSS, this work was able to fabricate a highly stretchable, semitransparent, and wholly solution- Processed alternating current electroluminescent device with unimpaired performance at 50% strain by using PEDOTS/EMIM TCB composite films as both bottom and top electrodes.
Abstract: Stretchable conductive materials have received great attention owing to their potential for realizing next-generation stretchable electronics. However, the simultaneous achievement of excellent mechanical stretchability and high electrical conductivity as well as cost-effective fabrication has been a significant challenge. Here, we report a highly stretchable and highly conducting polymer that was obtained by incorporating an ionic liquid. When 1-ethyl-3-methylimidazolium tetracyanoborate (EMIM TCB) was added to an aqueous conducting polymer solution of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), it was found that EMIM TCB acts not only as a secondary dopant but also as a plasticizer for PEDOT:PSS, resulting in a high conductivity of >1000 S cm–1 with stable performance at tensile strains up to 50% and even up to 180% in combination with the prestrained substrate technique. Consequently, by exploiting the additional benefits of high transparency and solution-processability of PEDO...
TL;DR: This review provides an insight into the synthesis and applications of innovative poly(ethylenedioxythiophene)-type materials for bioelectronics such as biocompatible conducting polymer layers, conducting hydrogels, biosensors, selective detachment of cells, scaffolds for tissue engineering, electrodes for electrophysiology, implantable electrodes, stimulation of neuronal cells or pan-bio electronics.
Abstract: Poly(3,4-ethylenedioxythiophene)s are the conducting polymers (CP) with the biggest prospects in the field of bioelectronics due to their combination of characteristics (conductivity, stability, transparency and biocompatibility). The gold standard material is the commercially available poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). However, in order to well connect the two fields of biology and electronics, PEDOT:PSS presents some limitations associated with its low (bio)functionality. In this review, we provide an insight into the synthesis and applications of innovative poly(ethylenedioxythiophene)-type materials for bioelectronics. First, we present a detailed analysis of the different synthetic routes to (bio)functional dioxythiophene monomer/polymer derivatives. Second, we focus on the preparation of PEDOT dispersions using different biopolymers and biomolecules as dopants and stabilizers. To finish, we review the applications of innovative PEDOT-type materials such as biocompatible conducting polymer layers, conducting hydrogels, biosensors, selective detachment of cells, scaffolds for tissue engineering, electrodes for electrophysiology, implantable electrodes, stimulation of neuronal cells or pan-bio electronics.
TL;DR: In this article, a hybrid polyaniline coated metal organic framework (MOF/PANI) was designed and fabricated via hydrothermal and in situ chemical polymerization methods.
TL;DR: The hybrid gel electrodes based on a polypyrrole gel framework and Fe3 O4 nanoparticles as a model system in this study demonstrate the best rate performance, the highest achieved mass ratio of active materials, and the highest achieve specific capacities when considering total electrode mass, compared to current literature.
Abstract: This study develops a tunable 3D nanostructured conductive gel framework as both binder and conductive framework for lithium ion batteries. A 3D nanostructured gel framework with continuous electron pathways can provide hierarchical pores for ion transport and form uniform coatings on each active particle against aggregation. The hybrid gel electrodes based on a polypyrrole gel framework and Fe3 O4 nanoparticles as a model system in this study demonstrate the best rate performance, the highest achieved mass ratio of active materials, and the highest achieved specific capacities when considering total electrode mass, compared to current literature. This 3D nanostructured gel-based framework represents a powerful platform for various electrochemically active materials to enable the next-generation high-energy batteries.
TL;DR: In this paper, the authors designed a sandwich structure with a conductive network and intimate contacts between nanosulfur and poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS).
Abstract: Lithium-sulfur batteries, as one of the most promising next-generation batteries, attract tremendous attentions due to their high energy density and low cost. However, their practical application is hindered by their short cycling life and low volumetric capacity. Herein, compact, flexible, and free-standing films with a sandwich structure are designed simply by vacuum filtration, in which nanosulfur is homogenously coated by graphene and poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). This unique hierarchical structure not only provides a highly conductive network and intimate contacts between nanosulfur and graphene/PEDOT:PSS for effective charge transportation, but also offers synergistic physical restriction and chemical confinement of dissoluble intermediate lithium polysulfides during electrochemical processes. Therefore, these conductive compact films, used directly as cathodes, show the highest reversible volumetric capacity of 1432 Ah L-1 at 0.1 C and 1038 Ah L-1 at 1 C, and excellent cycling stability with a minimal decay rate of 0.04% per cycle over 500 cycles at 1 C. Meanwhile, remarkable rate performance with a high capacity of 701 mAh g-1 at 4 C is also achieved. Soft-packaged batteries based on this flexible cathode are further fabricated and demonstrate excellent mechanical and electrochemical properties with little capacity decay under folded state, highlighting the practical application of our deliberately designed electrode in a flexible power system.
TL;DR: In this article, a soft-doping method based on spin-coating a solution of dopants in an orthogonal solvent is proposed to produce oriented and highly crystalline conducting polymer layers.
Abstract: A general method is proposed to produce oriented and highly crystalline conducting polymer layers. It combines the controlled orientation/crystallization of polymer films by high-temperature rubbing with a soft-doping method based on spin-coating a solution of dopants in an orthogonal solvent. Doping rubbed films of regioregular poly(3-alkylthiophene) s and poly(2,5-bis(3-dodecylthiophen- 2-yl) thieno[3,2-b] thiophene) with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F(4)TCNQ) yields highly oriented conducting polymer films that display polarized UV-visible-near-infrared (NIR) absorption, anisotropy in charge transport, and thermoelectric properties. Transmission electron microscopy and polarized UV-vis-NIR spectroscopy help understand and clarify the structure of the films and the doping mechanism. F(4)TCNQ(-) anions are incorporated into the layers of side chains and orient with their long molecular axis perpendicular to the polymer chains. The ordering of dopant molecules depends closely on the length and packing of the alkyl side chains. Increasing the dopant concentration results in a continuous variation of unit cell parameters of the doped phase. The high orientation results in anisotropic charge conductivity (sigma) and thermoelectric properties that are both enhanced in the direction of the polymer chains (sigma = 22 +/- 5 S cm(-1) and S = 60 +/- 2 mu V K-1 ). The method of fabrication of such highly oriented conducting polymer films is versatile and is applicable to a large palette of semiconducting polymers.
TL;DR: The result shows that using solution-processable small-anion salts such as TBAF as an n-dopant of organic conjugated polymers possessing lower LUMO (lowest unoccupied molecular orbital), less than -4.2 eV) can open new opportunities toward high-performance air-stable solution- Processable n-type thermoelectric (TE) conjugate polymers.
Abstract: Air-stable and soluble tetrabutylammonium fluoride (TBAF) is demonstrated as an efficient n-type dopant for the conjugated polymer ClBDPPV. Electron transfer from F− anions to the π-electron-deficient ClBDPPV through anion–π electronic interactions is strongly corroborated by the combined results of electron spin resonance, UV–vis–NIR, and ultraviolet photoelectron spectroscopy. Doping of ClBDPPV with 25 mol% TBAF boosts electrical conductivity to up to 0.62 S cm−1, among the highest conductivities that have been reported for solution-processed n-type conjugated polymers, with a thermoelectric power factor of 0.63 µW m−1 K−2 in air. Importantly, the Seebeck coefficient agrees with recently published correlations to conductivity. Moreover, the F−-doped ClBDPPV shows significant air stability, maintaining the conductivity of over 0.1 S cm−1 in a thick film after exposure to air for one week, to the best of our knowledge the first report of an air-stable solution-processable n-doped conductive polymer with this level of conductivity. The result shows that using solution-processable small-anion salts such as TBAF as an n-dopant of organic conjugated polymers possessing lower LUMO (lowest unoccupied molecular orbital), less than −4.2 eV) can open new opportunities toward high-performance air-stable solution-processable n-type thermoelectric (TE) conjugated polymers.
TL;DR: The weakness of CP-based neural probes can ultimately be eliminated and true long-term stable use of PEDOT on neural probes will be possible in future electrode generations by introducing two novel adhesion improvement strategies that can easily be integrated with standard microelectrode fabrication processes.
Abstract: Conducting polymers (CPs) have frequently been described as outstanding coating materials for neural microelectrodes, providing significantly reduced impedance or higher charge injection compared to pure metals. Usability has until now, however, been limited by poor adhesion of polymers like poly(3,4-ethylenedioxythiophene) (PEDOT) to metallic substrates, ultimately precluding long-term applications. The aim of this study was to overcome this weakness of CPs by introducing two novel adhesion improvement strategies that can easily be integrated with standard microelectrode fabrication processes. Iridium Oxide (IrOx) demonstrated exceptional stability for PEDOT coatings, resulting in polymer survival over 10 000 redox cycles and 110 days under accelerated aging conditions at 60 °C. Nanostructured Pt was furthermore introduced as a purely mechanical adhesion promoter providing 10-fold adhesion improvement compared to smooth Pt substrates by simply altering the morphology of Pt. This layer can be realized in a very simple process that is compatible with any electrode design, turning nanostructured Pt into a universal adhesion layer for CP coatings. By the introduction of these adhesion-promoting strategies, the weakness of CP-based neural probes can ultimately be eliminated and true long-term stable use of PEDOT on neural probes will be possible in future electrode generations.
TL;DR: In this article, a metal-free composite ink that contains graphene dots (GDs) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) was synthesized to serve as the counter electrode in a flexible dye-sensitized solar cell.
TL;DR: In this paper, the authors applied 3D printing of conductive microstructures for the functional optimization of lightweight and semi-transparent electromagnetic interference (EMI) shields, and the results revealed a significant improvement of the specific EMI shielding effectiveness of CNT/PLA nanocomposites printed as 3D scaffolds compared to hot-pressed in solid forms.
Abstract: Here we applied three-dimensional (3D) printing of conductive microstructures for the functional optimization of lightweight and semi-transparent electromagnetic interference (EMI) shields. Highly conductive 3D printable inks with electrical conductivities up to ∼5000 S m−1 were fabricated from carbon nanotubes/polylactic acid (CNT/PLA) nanocomposites. Solvent-cast 3D printing enabled us to fabricate conductive scaffold microstructures and investigate the influence of various important structural parameters (i.e., inter-filament spacing, number of layers and printing patterns) on their transparency and EMI shielding effectiveness. The results revealed a significant improvement of the specific EMI shielding effectiveness of CNT/PLA nanocomposites printed as 3D scaffolds compared to CNT/PLA hot-pressed in solid forms (∼70 vs ∼37 dB g−1 cm3). The transparency of the scaffolds could vary from ∼0% to ∼75% by modifying their printing patterns and inter-filament spacing. To the best of our knowledge the conductivity of the fabricated ink is the highest among the other reported 3D printable polymer composite inks and this is the first reported systematic study on EMI shielding using a 3D printing technique. These results are highly beneficial for the fabrication and structural optimization of EMI shields where light and/or transparent structures are advantageous, such as in aerospace systems, portable electronic devices or smart fabrics.
TL;DR: In this article, the conductivity of polypyrrole-coated fabrics was investigated and compared to polyaniline-based fabrics with and without the deposition of silver nanoparticles.
TL;DR: This new-age microwave-absorbing material, powered by multifunctionality and tunable magnetodielectric properties, henceforth offers an amendable, cost-effective replacement to the existing solutions.
Abstract: Conducting polymer composites containing ferromagnetic grafted-graphene derivatives are already appreciated for their lightweight, flexibility, and cost effectiveness in terms of microwave absorption To further leverage the said properties of this wonder material, we propose a highly efficient replacement by blending conducting multiwall carbon nanotube (MWCNT) and FeCo anchored covalent cross-linked reduced graphene oxide (rGO) with poly(vinylidene fluoride) (PVDF) Interconnected conducting network of MWCNTs introduces higher electrical conductivity in the blend which is essential for microwave absorption FeCo-anchored porous interconnected rGO framework was designed via solvent-mediated in situ coreduction in the presence of Fe(II) and Co(II) precursors Resulting cross-linked-rGO/FeCo displays fascinating coexistence of ferromagnetism and conducting-dielectric behavior, while largely preserving the robust 3D porous interconnected structure Coupled with conducting MWCNTs, diamine cross-linked rGO/Fe
TL;DR: Both the in situ polymerization and solution process can enhance the dispersion homogeneity of graphene in the polymer matrix, bringing about increased nanointerfaces in the PPy/GNs/PANi composite.
Abstract: Polypyrrole/Graphene/Polyaniline (PPy/GNs/PANi) ternary nanocomposite with high thermoelectric power factor has been successfully prepared through the combination of in situ polymerization and solution process. FTIR, Raman spectra, XRD, and SEM analyses show the strong π–π interactions existed among PPy, GNs, and PANi, leading to the formation of more ordered regions in the composite. Both the in situ polymerization and solution process can enhance the dispersion homogeneity of graphene in the polymer matrix, bringing about increased nanointerfaces in the PPy/GNs/PANi composite. The thermoelectric properties of Polypyrrole/Graphene (PPy/GNs), Polyaniline/Graphene (PANi/GNs), and PPy/GNs/PANi composites are measured at different temperatures after being cold pressed. Consequently, the PPy/GNs/PANi composite with 32 wt % graphene demonstrates optimal electrical conductivity, Seebeck coefficient and extremely high power factor of up to 52.5 μ W m–1 K–2, which is almost 1.6 × 103 times, 1.4 × 103 times, 2.7 t...