导电高分子PEDOT／PSS保护银纳米颗粒的制备与表征

利用导电高分子聚（3，4-二氧乙基噻吩）／聚（对苯乙烯磺酸）（PEDOT／PSS）作保护剂，制备了银纳米颗粒，用UV-Vis和TEM对其进行了表征．结果表明，选择合适量的PEDOT／PSS保护剂可以得到大小分布较窄银纳米颗粒．     

Anisotropic Motion of Electroactive Papers Coated with PEDOT/PSS

We report on an anisotropic actuation of electroactive papers with a PEDOT/PSS coating in ambient air. PEDOT/PSS‐coated papers were prepared by wetting Manila papers with a concentrated PEDOT/PSS aqueous dispersion and subsequent drying. The electroactive papers displayed a contractile stress when an external voltage was applied, the magnitude and direction of the stress depending on the relative orientation of paper fibers and the loading direction of the coating. We also demonstrated that a butterfly‐like reversible bending motion of the PEDOT/PSS coated paper occurred when the voltage switching between on and off.

     

PEDOT/PSS水性分散液的合成、电导率提高方法及机理

PEDOT/PSS电导率通常小于1 S/cm,较低的电导率限制了其在电化学器件中的广泛应用。PEDOT/PSS膜电导率的提升成为其广泛应用的重要前提。综述了PEDOT/PSS水性分散液的合成、PEDOT/PSS膜电导率降低的机理,并介绍了提高PEDOT/PSS膜电导率的方法和相关机制,这对于提升PEDOT/PSS的应用范围和空间具有重要的意义。     

Freeze-drying and mechanical redispersion of aqueous PEDOT:PSS

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films are attracting famous applications in antistatic coating, energy storage and conversion, printed electronics, and biomedical fields due to their conductivity, optical transparency and flexibility. However, PEDOT:PSS has poor dispersion stability during long-term storage and transport. Moreover, the dried PEDOT:PSS films are insoluble in any solvent and cannot be redispersed again. In comparison to bake drying, here, a feasible strategy to achieve mechanically redispersed PEDOT:PSS with the help of freeze-drying process was reported. The redispersed PEDOT:PSS can recover not only the initial characters such as pH, chemical composition, viscosity, and particle size under similar solid contents, but also conductivity and surface morphology of treated films. In addition, the treated film exhibits self-healing properties similar to pristine film in terms of mechanical and electrical properties. This technology enables reuse and overcomes the technical problems of PEDOT:PSS dispersion, realizing real-time processing to meet variable applications.     

Chemical cross-linking of conducting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) using poly(ethylene oxide) (PEO)

Hybrid films of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) were prepared with different molecular weights of poly(ethylene oxide) (PEO). The cross-linking reaction between PEO and PEDOT:PSS was performed at high temperature and confirmed by using differential scanning calorimeter (DSC), contact angle measurement, and solid-state ¹H NMR. The effect of chemical reaction on the conductivity and morphology of these hybrid films was studied by using 4-point probe and atomic force microscope (AFM), respectively. As-spun PEO/PEDOT:PSS films have lower electric conductivity due to the addition of nonconductive PEO, and exhibits no molecular weight dependence on conductivity. After chemical cross-linking reaction at high temperature, only PEDOT:PSS films with lowest molecular weight PEO additives show enhanced conductivity with increasing reaction time. AFM result indicates that the heat-treated PEO/PEDOT:PSS hybrid films show grain-like morphology compared to ethylene glycol treated PEDOT:PSS films which shows continuous PEDOT domain. In the present work we demonstrate that the cross-linking reaction can be used to improve the wet stability of PEDOT:PSS nanofiber, showing good water resistance and excellent dimensional stability.     

PEDOT:PSS导电自支撑薄膜的合成与制备

以3,4-乙烯二氧噻吩（EDOT）为原料，聚对苯乙烯磺酸钠（PSS-Na）为分散剂和掺杂剂，通过化学氧化合成法在水体系中聚合制备了聚(3,4-乙烯二氧噻吩):聚苯乙烯磺酸（PEDOT:PSS）悬浮液，通过真空抽滤的方法制备了PEDOT:PSS自支撑柔性导电薄膜。通过FTIR、UV-Vis对聚合产物结构进行了表征与确认，通过四探针电导率测试、SEM、拉伸断裂强度测试对PEDOT:PSS薄膜的导电性、微观形貌与力学性能进行了表征。结果表明，成功制备了PEDOT:PSS目标产物，在氧化剂与单体物质的量之比为0.875时达到最佳电导率（19.19 S/cm）。自支撑薄膜厚度约18 μm，在25 ℃，40%~60%相对湿度范围内拉伸断裂强度达到45~60 MPa，具有良好的导电性与机械性能。     

Highly Stretchable and Sensitive Flexible Strain Sensor Based on Fe NWs/Graphene/PEDOT:PSS with a Porous Structure

With the rapid development of wearable smart electronic products, high-performance wearable flexible strain sensors are urgently needed. In this paper, a flexible strain sensor device with Fe NWs/Graphene/PEDOT:PSS material added under a porous structure was designed and prepared. The effects of adding different sensing materials and a different number of dips with PEDOT:PSS on the device performance were investigated. The experiments show that the flexible strain sensor obtained by using Fe NWs, graphene, and PEDOT:PSS composite is dipped in polyurethane foam once and vacuum dried in turn with a local linearity of 98.8%, and the device was stable up to 3500 times at 80% strain. The high linearity and good stability are based on the three-dimensional network structure of polyurethane foam, combined with the excellent electrical conductivity of Fe NWs, the bridging and passivation effects of graphene, and the stabilization effect of PEDOT:PSS, which force the graphene-coated Fe NWs to adhere to the porous skeleton under the action of PEDOT:PSS to form a stable three-dimensional conductive network. Flexible strain sensor devices can be applied to smart robots and other fields and show broad application prospects in intelligent wearable devices.     

Investigations on performance of PEDOT:PSS/V2O5 hybrid symmetric supercapacitor with redox electrolyte

Nanocomposites of PEDOT:PSS with V₂O₅ nanoparticles are synthesized by simple physical mixing of the two with different weight percentages of the latter and their performance as supercapacitor electrode materials is verified. Best performance is obtained for an optimum weight percent of 16.8% of V₂O₅. The specific capacitance and specific energy of the composite with 16.8% V₂O₅ increases by more than two fold, with increase in specific power, as compared to that of pristine PEDOT:PSS device. This is attributed to increase in conductivity brought about by the presence of V₂O₅ nanoparticles, easier transportation and intimate contact of electrolyte ions with the nanolayers of V₂O₅ due to the intercalation of PEDOT:PSS between the layers, and additional redox reactions due to various oxidation states of vanadium element, besides redox electrolyte effects. This is further confirmed by the reduced ESR of the composite device as compared to that of pristine PEDOT:PSS device.     

Characterization and actuation behavior of SPS/SGO ion exchange polymer actuator based on PEDOT: PSS/SGO composite electrode

ABSTRACT

This paper studied the fabrication of new hybrid-type poly(3,4- ethylene dioxythiophene) (PEDOT)/sulfonated graphene oxide electrode-based polymer actuator produced by film casting method. Sulfonated Poly(1,4-phenylene ether-ether sulfone) (SPS) ion-exchange polymer membrane-based ionic polymer composite actuators were fabricated using the different concentration of SGO. The characterization and actuation were demonstrated. By altering SGO concentration, four different SPS based membrane actuators were analyzed. The effects of SGO concentration on the morphology, proton conductivity, ion exchange capacity, and water uptake capability were studied. The maximum tip displacement and force by varying concentration of SGO were evaluated for the actuation performance.     

High conducting multilayer films from poly(sodium styrenesulfonate) and graphite nanoplatelets by layer-by-layer self-assembly

Exfoliated graphite (G) nanoplatelet was modified with hexadecyltrimethylammonium bromide (C₁₆TAB) and was constructed as multilayer films by electrostatic self-assembly. A [poly(sodium styrenesulfonate)/graphite]_n (PSS/G)_n multilayer film was self-assembled by alternate adsorption of polyanionic PSS and cationic graphite nanoplatelets G. An uniform deposition process was detected by UV-vis absorption spectra. The (PSS/G)_n multilayer film exhibits an excellent electrical conductivity in the range of 50-200 S cm⁻¹, when bilayer number (n) exceeds a threshold value four, the conductivity of the multilayer film increases dramatically. Cyclic voltammogram measurement reveals that the (PSS/G)_n film with more bilayer has small charge-transfer resistance and high electrocatalytic activity.     

An effective layer-by-layer adsorption and polymerization method to the fabrication of polyoxometalate-polypyrrole nanoparticle ultrathin films

A layer-by-layer (LbL) adsorption and polymerization method was developed for the controllable preparation of polypyrrole (PPy) nanoparticles within ultrathin films. By repetitive adsorption of pyrrole and subsequent polymerization with 12-molybdophosphoric acid, the polyelectrolyte multilayer films containing PPy nanoparticles were fabricated. UV-visible absorption spectrocopy, Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM) and cyclic voltammograms (CVs) were used to characterize the PPy nanoparticles and their multilayer thin films. UV-visible spectra indicate that the growth of PPy nanoparticles was regular and occurred within the polyelectrolyte films. The size of prepared PPy nanoparticles was found by TEM to increase with the increasing of polymerization cycles. The electrochemistry behavior of the multilayer thin films was studied in detail on ITO. The results suggest that the LbL adsorption and polymerization method developed herein provides an effective way to prepare PPy nanoparticles in the polymer matrix.     

Flexible and Highly Conductive AgNWs/PEDOT:PSS Functionalized Aramid Nonwoven Fabric for High-Performance Electromagnetic Interference Shielding and Joule Heating

High-performance multifunctional textiles are highly demanded for human health-related applications. In this work, a highly conductive nonwoven fabric is fabricated by coating silver nanowires (AgNWs)/poly(3,4-ethyl enedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) on a poly(m-phenylene isophthalamide) (PMIA) nonwoven fabric through a multistep dip coating process. The as-prepared PMIA/AgNWs/PEDOT:PSS composite nonwoven fabric shows an electrical resistance as low as 0.92 ± 0.06 Ω sq⁻¹ with good flexibility. The incorporation of the PEDOT:PSS coating layer improves the adhesion between AgNWs and PMIA nonwoven fabric, and also enhances the thermal stability of the composite nonwoven fabric. Electromagnetic interference (EMI) shielding and Joule heating performances of the PMIA/AgNWs/PEDOT:PSS composite nonwoven fabric are also investigated. The results show that the average EMI shielding effectiveness (SE) of the single-layer nonwoven fabric in X-band is as high as 56.6 dB and retains a satisfactory level of SE after being washed, bended, and treated with acid/alkali solution and various organic solvents. The composite nonwoven fabric also exhibits low voltage-driven Joule heating performance with reliable heating stability and repeatability. It can be envisaged that the multifunctional PMIA/AgNWs/PEDOT:PSS nonwoven fabric with reliable stability and chemical robustness can be used in EMI shielding devices and personal thermal management products.     

Antimicrobial efficacy of N-halamine coatings prepared via dip and spray layer-by-layer deposition

Antimicrobial coatings in which the active agent (e.g. N-halamine) can regenerate activity represent a promising way to prevent microbial cross-contamination. A reported method for applying coatings containing antimicrobial N-halamines is layer-by-layer (LbL) application of polyelectrolytes which form N-halamines upon cross-linking. Prior reports on dip LbL have demonstrated the potential of this technology; however, spray LbL represents a more commercially translatable technology. In this work, dip and spray LbL methods were used to coat polypropylene (PP) with N-halamine containing bilayers of cross-linked polyethyleneimine (PEI) and polyacrylic acid (PAA). Materials were characterized using atomic force microscopy, ellipsometry, contact angle, Fourier transform infrared spectroscopy, and colorimetric assays for chlorine and amine contents. Both methods exhibited >99.999% reduction against Listeria monocytogenes with application time for spray LbL taking 6% of the time required for dip LbL. Spray LbL fabrication of N-halamines is a rapid and inexpensive method to fabricate rechargeable antimicrobial surfaces.     

Nanocomposites of PEDOT:PSS with Graphene and its Derivatives for Flexible Electronic Applications: A Review

Rapid technological advancements in flexible nanoelectronics have fueled the need for high-performance materials with advanced structural architectures and superior properties. In this regard, conducting polymer nanocomposites are at the forefront of current innovative research owing to their excellent properties. Among these sets of unique materials, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS) nanocomposites continue to pave the way in several applications including those entailing thermoelectricity, transparent electrodes, photovoltaics, technical coatings, lighting, sensing, bioelectronics, hole transport layers, interconnectors, electroactive layers, and motion-sensing conductors. The versatility and intriguing properties of these composites, particularly with 2D nanomaterials, have garnered significant attention from academia as well as industry. Therefore, in this review, the latest developments in PEDOT:PSS nanocomposites with graphene and its derivatives are focused on. First, the synthesis and fabrication of PEDOT:PSS nanocomposites with emphasis on recent techniques developed to overcome the challenges associated with direct production is discussed. Thereafter, the characterization and thermoelectric properties of the materials are explained. This provides detailed insights into the characteristic features of various nanocomposites and the influence of individual nanoparticles in the PEDOT:PSS matrix. Then, a conclusion, including a critical summary of the extensive applications of the PEDOT:PSS/graphene nanocomposites for electrochemical, electrostatic, optoelectronic, and thermoelectric devices, is provided.     

PEDOT:PSS coating on specialty papers: Process optimization and effects of surface properties on electrical performances

In this study, the effects of different paper substrates on the electrical resistance of conducting polymer films are reported. A novel method of bar coating is used for the fabrication of organic conductive films on various substrates. Solutions to improve the continuity of conductive thin film in order to enhance the electrical properties are demonstrated. In order to compare the capability of these different substrates for a potential use in the organic electronic field, sheet resistance measurements were made. It is emphasized that substrate roughness and surface energy are two fundamental parameters, due to their significant impact on sheet resistance. Two methods to overcome bad paper surface properties are proposed. The first consists in the superimposition of conductive polymer layers and the second in the use of a protective layer.     

Amperometric glucose biosensor prepared with biocompatible material and carbon nanotube by layer-by-layer self-assembly technique

Prussian Blue (PB) based glucose biosensor was prepared by immobilizing glucose oxidase (GOD) in layer-by-layer (LBL) films with chitosan (Chi) and multi-walled carbon nanotubes (MWNTs). With the increasing of Chi/MWNTs/GOD layers, the response current to glucose was changed regularly and reached a maximum value when the number of layer was six. At the optimized condition, the biosensor exhibits excellent response performance to glucose with a linear range from 1 to 7 mM and a low detection limit of 0.05 mM. The biosensor also shows a high sensitivity of 8.017 μA mM⁻¹ cm⁻², which is attributed to the biocompatible nature of the LBL films. Furthermore, the biosensor shows rapid response, good reproducibility, long-term stability and freedom of interference from other co-existing electroactive species such as ascorbic acid and acetaminophen.     

Phase Segregation of PEDOT:PSS on Textile to Produce Materials of >10 A mm−2 Current Carrying Capacity

Conductive textiles with exceptional electrical properties have been prepared by coating the conjugated polymer, poly(3,4‐ethylenedioxyphiophene)‐polystyrenesulfonate(PEDOT‐PSS), on polyethylene terephthalate (PET) nonwoven fabrics. Phase segregation from covalent bond formation to surface silica particles generates PEDOT‐PSS coated textiles that hold potential for wearable electronics due to the breathability of the fabric, low toxicity, easy processing and lightweight with high current carrying capacity. The conductive textiles were demonstrated for applications such as electrical connections and resistive heating.

     

Carbon/carbon composites prepared by chemical vapour deposition

This paper summarizes the results of the authors' work on composites prepared by chemical vapour deposition (CVD), using propylene as a source of carbon and various substrates (cellulose carbon, natural graphite, different grades of carbon fibres bonded by phenolic or CVD carbon). The equations relating

1. (i) open porosity P with infiltration rate (− dP/dt = kP).

2. (ii) apparent density of the composites d_app with P (d_app = nP + q).

3. (iii) composite properties Y with d_app (Y = ad_app^b) have been confirmed for the systems studied up to the highest composite densities attained. The constants k, n, q, a and b vary with infiltration conditions, nature of the substrate (involving bonding carbon in the skeleton), heat treatment (HT) conditions and geometrical factors.

For a given set of conditions, infiltration rate increases with temperature and the partial pressure of propylene, but decreases with residence time. Contrary to the composite properties, the kinetics of infiltration are not influenced by the nature of the substrate, except for the initial stage before the substrate is coated by the CVD carbon, but depends on the shape and size of open pores. The influence of the nature of the carbon used to bond the fibres may be of particular importance for composite properties, the latter being also influenced by the state of the surface of the fibres. Among the geometrical factors, the studied effect of fibre content has been found to strongly influence the infiltration rate, in agreement with predictions, as well as the composite properties. The influence of HT on composite properties can be explained by the resulting structural changes in the substrate and the matrix and by the effect of stress relaxation.

Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonic Acid) (PEDOT:PSS) Conductivity Enhancement through Addition of Imidazolium-Ionic Liquid Derivatives

Here, insignificant conductivity enhancement of PEDOT:PSS through adding different amounts of 2-methylimidazolium ionic liquids into PEDOT:PSS aqueous solutions is reported. Maximum conductivity was reached through 2-methylimidazolium hydrogen sulfate (5 wt.%) addition. It seems that observed conductivity enhancement mainly results from the impact of ionic liquids on the electrical properties and conformational change of PEDOT chains, and through weakening of the electrostatic interactions between PEDOT and PSS. Also, better conductivity was achieved through weak interactions between PEDOT and the PSS chain, which changes the PEDOT conformation and further delocalizes the polarons, as well as changes the electron transport properties.     

A red-to-gray poly(3-methylthiophene) electrochromic device using a zinc hexacyanoferrate/PEDOT:PSS composite counter electrode

In this paper, we describe a novel red-to-gray poly(3-methylthiophene) (PMeT) electrochromic device (ECD) with the aid of a zinc hexacyanoferrate (ZnHCF)/PEDOT:PSS counter electrode. The application of ZnHCF to an ECD is first reported. ZnHCF has long suffered from poor deposition yield problem, but we demonstrate that a robust ZnHCF film can be prepared by spin coating of a liquid suspension composed of ZnHCF nanoparticles and PEDOT:PSS ink on ITO. It was found that the ZnHCF/PEDOT:PSS composite worked much better with PMeT than pure ZnHCF or pure PEDOT:PSS from both electrochemical and optical aspects. With a LiClO₄/PC electrolyte, the PMeT ECD having ZnHCF/PEDOT:PSS as its counter electrode could be reversibly switched between its red state (>0.8 V) and its gray state (<0 V). For a 2 cm × 2 cm prototype device, the response time for coloration was less than 1 s. The maximum transmittance modulation of the device could attain 45.3% at 750 nm, which resulted in a corresponding coloration efficiency of 336.8 cm²/C. The maximum contrast ratio was 5.45 at 720 nm. In addition, the charge capacity of the ECD could retain 95% of its original value after 10,000 cycles of cyclic voltammetry aging test, although an electrodeposited PMeT film alone could be cycled several hundred times only. To sum up, this work proposes a new, cost-effective transparent counter electrode and brings a stable, high visual-contrast PMeT ECD prototype for further development of a red-color bistable display.