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Materials with nonstandard physical properties are widely used in various fields of science and technology, from microelectronics to heavy industrial installations. At one time, international scientific teams carried out mathematical calculations showing that the most promising compounds of B–C structures which, under certain external conditions and concentration ratios, have strong chemical sp and sp bonds. Such materials are characterized by high hardness, resistance to aggressive media, and conductivity. This work is aimed at the synthesis and study of carbon-containing BC films. This paper presents the results of measuring a thin BC film. The spectral characteristics of the film, data on its layer thickness, conductivity, and composition were obtained by using X-ray, Raman, and photoelectron spectroscopy. [ABSTRACT FROM AUTHOR]

The shortage of fossil energy and the environmental pollution caused by its use promote the development of renewable clean new energy. Energy storage devices are the best choice to convert and store them into efficient and convenient electric energy, and the light weight of the conductive film plays an important role in energy storage devices. Conductive films as electronic conduction layers have become a research hotspot due to their high electronic conductivity, environment‐friendly, low cost, flexibility, transmittance, high chemical stability, good film forming, and excellent mechanical properties. The material selection, conductivity, preparation methods, and adhesion to the substrate of the conductive films all affect the performance of the energy storage devices. Herein, the conductive properties of conductive films of metal materials, carbon materials, conductive polymers, metal oxides, metal nitrides, and other compounds are reviewed. The application of conductive films as electron conduction layers in solar cells, supercapacitors, lithium‐ion batteries, and solid aluminum electrolytic capacitors is analyzed. The future development trend of conductive films in energy storage devices is prospected. [ABSTRACT FROM AUTHOR]

Conductive flexible films are successfully synthesized from polyvinyl alcohol matrix and poly(aniline‐co‐carbazole) charge carrier. To improve the mechanical properties of polyvinyl alcohol and promote charge transition in the conductive copolymer, dual purpose sulfonated multiwall carbon nanotube is added. Conductivity is enhanced via sulfonic acid protonic dopant and mechanical property is increased by its hexagonal nanorods. Nanocomposites are prepared by adding 0.025, 0.050, and 0.075 g of carbon nanotube which is added at 1%, 3%, and 5% loads to the polymer matrix. Films are characterized by infrared, UV–vis, X‐ray diffraction, scanning electron microscopy, and thermogravimetric analysis. Conductivity is measured by the four‐probe technique and mechanical property is assessed through tensile tests and dynamic mechanic thermal analysis. A 5 × 10−6 S cm−1 conductivity and 116 MPa tensile strength are recorded for the conductive film with optimum dopant/nanocomposite loads. The electrochemical property and corrosion resistance are studied by cyclic voltammetry and Tafel curves, respectively. The conductive films show an increase in corrosion potential and a decrease in corrosion current referring to a reliable corrosion protection film. The water uptake and contact angle of the films are measured to be 157% and 80.1° respectively to confirm its required hydrophilic property. [ABSTRACT FROM AUTHOR]

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The developments in inkjet printing technology and the printed electronics industry in the past two decades have provided cost-effective, environmentfriendly, and reliable alternates to traditional methods of fabricating electrical devices. However, most commercial metallic inks require high sintering temperatures to form desired functional patterns, which limits the applications of printed electronics in scenarios that require electrical devices on thermally sensitive substrates, like biomaterials or bio-synthetic composite materials. This study provides the synthetic route of a novel silver-based metal organic decomposition (MOD) ink which is used to form highly conductive silver films on the thermally sensitive skin-inspired silk/epoxy composite substrates by directly inkjet printing with accurate pattern control, whilst self-decomposing and sintering at room temperature. The fabricated silver patterns on the thermally sensitive silk/epoxy composite substrate are highly conductive with conductivity of 4.65 × 104 S m-1. These silver patterns also show impressive malleability as bulk silver films, which can be further developed into motion sensors for wearable devices or medical applications. Our strategy provides a general platform for electronic functionalization without temperature constraints. The particle-free, reactive silver-precursor, and lower sintering temperature of the ink also widen the choices of substrates, as exemplified herein with outstanding printing quality and high electrical conductivity (1.20 × 106 S m-1) also achieve on paper. [ABSTRACT FROM AUTHOR]

Silver nanofiber (AgNF) is a promising candidate for flexible electrodes because of its outstanding physical and electrical properties. However, for mass production of devices, the stability and robustness of AgNF‐based electrodes are still required to be improved. In this work, a facile and cost‐effective technique is developed to embed AgNFs into engineering‐applied polyimide (PI) substrate, which is realized through a silver‐catalyzed oxidative decomposition process. The embedded structure effectively solves surface roughness and adhesion issue, improving electrode performance during scratching and tape peeling test. Besides, the trenches formed during embedding of AgNFs can be used to deposit metals to enhance heat‐tolerance property of electrode. More importantly, benefiting from excellent flexibility of AgNFs and PI film, along with well protection realized by the embedded structure and electroplated metal, the electrodes show outstanding bending stability. Finally, a flexible nanoheater with good heating property and mechanical flexibility is fabricated to demonstrate potential application of the electrode. It is believed that such a method developed in this work will facilitate the fabrication of flexible electronics with high performance. [ABSTRACT FROM AUTHOR]

Abstract The properties of organic polymeric materials can be chemically fine-tuned by the implementation of functional groups or units within the backbone. Especially the inclusion of coordinated metal centers offers a nearly infinite toolbox to adjust properties and thus potential applications. In particular, salen and salphen complexes are widely known to be highly efficient homogenous catalysts. They are also used as luminescent materials and devices or as supramolecular building blocks. This review focusses on the class of salen- and salphen-containing organic polymers, from 1D to 3D. Besides the comparison of synthetic polymerization methods, properties and applications are discussed, with an emphasis on porous 2D and 3D polymeric metal salphens and salens for heterogeneous catalysis and gas sorption.

Ionogels have been extensively studied as ideal flexible and stretchable materials by virtue of the unique properties of ionic liquids, such as non‐volatility, non‐flammability, and negligible vapor pressure. However, the generally low ionic conductivity of the current ionogels limits their applications in the market of highly conductive, flexible, and stretchable electrical devices. Here, the fabrication of highly electrically conductive ionogels is reported by combining composite liquids consisting of 1‐ethyl‐3‐methylimidazolium dicyanamide ([EMIM][DCA]) and poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with flexible negative‐charged poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPS) hydrogel. The generated composite film exhibits high electrical conductivity up to about 38 S cm−1 with the maximum tensile strain of 45% and fracture stress of 27 kPa. In addition, it is demonstrated that the composite film can maintain conductivity in a high level under different mechanical deformations, and can also be used as flexible sensors in a wide temperature range from −58 to 120 ℃. It is believed that the designed composite film would expand the applications of flexible conductive materials where both high conductivity and robust mechanical flexibility are required. [ABSTRACT FROM AUTHOR]

The growing appeal of carbon nanotube composites in the contemporary market derives from their exceptional thermal and chemical stability, coupled with electrical conductivity. In this study, we combined these salient features with a biobased epoxy matrix having vitrimeric properties, hence being reprocessable and resheapable, to obtain a biobased conductive coating. Epoxidised castor oil (ECO) was chosen as a monomer precursor for the straightforward synthesis. The synthesis relied on a cationic UV-curing process, embedding the conductive carbon nanotubes in the matrix. Photo DSC and transmission FTIR analysis were conducted to determine the final conversion of the epoxy rings in the cationic photocuring process. Thermo-mechanical properties were evaluated by tensile tests, and DMTA. Thermal stability was assessed by TGA. Dielectric spectroscopy confirmed increased electrical conductivity in the presence of increasing CNT content, reaching a percolation threshold at 0.5 phr of CNTs. Vitrimeric properties were proved by stress relaxation experiments, and the UV-cured composite underwent a thermo-activated transesterification reaction starting from 70 °C, catalysed by dibutyl phosphate. Overall, the ECO-CNT composite showed high thermal resistance (up to 400 °C) electrical conductivity with 0.5 phr CNT concentration, and vitrimeric properties. The study can be, therefore, considered a promising starting point to obtain sustainable biobased and electrically conductive vitrimers. [Display omitted] • Cationic photopolymerization of bio-based epoxy monomer. • Conductive composites. • Vitrimers. [ABSTRACT FROM AUTHOR]

Novel flexible anisotropic conductive film with light‐controllable property is designed and constructed. The film is composed of electrospun polymeric nanobelts array loaded with TiO2 nanoparticles. The products are characterized by scanning electron microscopy, X‐ray diffractometry, thermal gravimetric analysis, and ultraviolet–visible absorption spectroscopy. The conductivity of the materials along two perpendicular directions of the film surface is investigated under dark and light irradiation conditions. The results reveal that the film is insulative in all directions under dark condition. Under irradiation, the light resistance along the length direction of the nanobelts is three orders of magnitude lower than the dark resistance, and the light resistance along the length direction of the nanobelts is two orders of magnitude lower than that along the perpendicular direction on the film surface. The effects of loading quantity of TiO2 nanoparticles and ratio of polyethylene oxide (PEO) to polymethylmethacrylate (PMMA) on the properties of the products are studied, and the influencing mechanism is proposed. This kind of anisotropic conductive film with new characteristics has broad application prospects in controllable flexible circuits and other fields. [ABSTRACT FROM AUTHOR]

Evaporative crystallization is a simple and widely used technique to obtain crystals. However, this is not well matching with preparation of nano scale crystals. In this study, a new method is established of self‐controlled evaporative crystallization of silver acetate in aqueous solution into crystalline silver acetate nanowire, which can conduct to the fabrication of conductive AgNWs films without presynthesis of metallic silver and printing equipment. In this method, the most important concept is to self‐control the anisotropic crystallization of metal ion by designed amphiphilic polyethyleneimine‐block‐polyphenyloxazoline (PEI‐b‐PPOZ) copolymers. Only casting an aqueous solution of silver acetate (AgOAc) containing PEI‐b‐PPOZ copolymers on substrate made silver acetate to grow spontaneously up towards networked crystalline nanowires (with high aspect ratio over 3000) film. This is completely directed by PEI‐b‐PPOZ block copolymers with water evaporation at ambient conditions. Heating of the crystalline AgOAc nanowires film at 200 °C yields metallic silver nanowires films which exhibit low sheet resistance of 20 Ω per sq indicating that the crystalline AgOAc nanowires can self‐template the thermal decomposition of AgOAc to give metallic nanowires. [ABSTRACT FROM AUTHOR]

An imidazolium‐based ionic liquid, 1‐ethyl‐3‐methylimidazolium diethyl phosphate ([Emim]DEP) was used to dispense graphene nanoplates (GN) and multiwalled carbon nanotubes (MWCNTs) as well as dissolve cellulose for fabricating composite conductive films. The effects of GN, MWCNTs, and cellulose mass ratios on the electrical conductivity and morphology of the films were investigated. The interaction between GN, MWCNTs, and cellulose was analyzed by SEM, X‐ray diffraction (XRD), TGA, and Raman spectroscopy. The results indicate that [Emim]DEP plays a vital and irreplaceable role in GN and MWCNTs dispersion, cellulose dissolution, and porous formation during the regeneration and drying processes. MWCNTs linked flaky GN and a hybrid structure was constructed elaborately to form a better conductive path and improve the conductivity as well as increase the film stability. For the XRD result, the carbonized GN‐MWCNTs‐cellulose films exhibited the graphitic peaks, showing that the films still retained the structure of carbon atoms or molecules. Besides, the maximum conductivity of carbonized GN‐MWCNTs‐cellulose (7:3:2) composite film was up to 9,009 S m−1, due to the small carbon clusters formation and the high degree of graphitization. Further, the carbonized films were applied as anodes in Li‐ion battery and showed good electrochemical performance. The best cyclic stability (i.e., discharge/charge capacity) of 438/429 mA h g−1 and coulomb efficiency of 50.2% were obtained. This novel and sustainable design is a promising approach to obtain cellulose‐based conductive films and anodes for Li‐ion battery applications. [ABSTRACT FROM AUTHOR]

We demonstrate a simple noncovalent functionalization technique, which involves graphite exfoliation and subsequent coating of the resulting graphene nanoplatelets (GNPs) with trimellitic anhydride (TMA), using a thermomechanical exfoliation process. TMA adsorbs on the surface of the GNPs, resulting in a reduction of the specific surface area to 312 ± 9 m 2 /g compared to 410 ± 12 m 2 /g for the unmodified GNPs. Detailed imaging, thermogravimetric, and X-ray diffraction analysis showed that the modified GNPs (TMA-GNPs) maintain similar structure to the unmodified GNPs. The presence of functional groups, confirmed by X-ray photoelectron spectroscopy analysis, caused an increase in the surface energy from 45.6 mJ/m 2 for the GNPs to 57.9 mJ/m 2 for TMA-GNPs. The resulting coated TMA-GNPs form stable dispersions in water while maintaining their inherent conductive properties, thus enabling applications, such as the manufacture of conductive films and supercapacitors. As a proof-of-concept, electrodes for supercapacitors are prepared from concentrated aqueous dispersions of the functionalized GNPs. Electrochemical characterization of the supercapacitors using electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charge/discharge tests showed a specific capacitance of 22.2 F/cm 3 at a scan rate of 1 mV/s from cyclic voltammetry and 17.3 F/cm 3 at a current density of 1 A/g from galvanostatic charge/discharge tests, with a 90% capacitance retention after 10,000 cycles.

• Effect of a conducting film set near PZT lateral electric field resonator is studied. • Film conductivity change affects the resonant frequency in certain conductivity range. • Film conductivity change affects maximum value of real part of electrical impedance. • Pointed change of maximum value of real part of electrical impedance may achieve 57%. • Results are useful for developing a gas sensors based on PZT piezoelectric resonators. In this paper, we investigated theoretically and experimentally the effect of the conductivity of the film located in the immediate vicinity of the free side of a piezoelectric resonator based on the PZT ceramics on its characteristics. It is shown that with increasing the conductivity of the film at first the parallel resonant frequency does not change, then it decreases in a certain interval and after that remains practically constant. With increasing the width of the gap between the film and the resonator, the resonant frequency increases and reaches the saturation. At that the degree of the total frequency change decreases with decreasing the conductivity of the film. We also investigated the dependence of the maximum value of the real part of the electrical impedance on the film conductivity at the different values of the width of the gap between the film and the resonator. The dependences of the maximum value of the real part of the electrical impedance on the width of the gap between the film and the resonator are also obtained for different values of the film conductivity. A comparison of the theoretical and experimental data showed their good qualitative agreement. [ABSTRACT FROM AUTHOR]

A deep eutectic solvent (DES) was employed to purify cellulose by depolymerizing agricultural waste walnut shells (WS) at 90 ℃ from 1.5 to 3.0 h. The pretreatment achieved an 88.57% delignification rate and yielded 33.62% cellulose solids (CS), with 77.63% cellulose and 13.11% lignin contained in CS. The DES pretreatment exposed functional groups on the surface of cellulose and resulted in a 24.7% increase in crystallinity. Suspension with a homogeneous distribution of lignin-containing cellulose nanofibers (LCNF) was made by ultrasonic dispersing (650 W, 30 min), and the average length of 1406 nm, the ζ-potential of − 17.65 mV. Higher lignin content led to cross-linking effect which produced a heightened degree of entanglement of LCNF while increasing the UV-shielding property and thermal stability. Additionally, LCNF stabilized the dispersion of multi-walled carbon nanotubes (MWCNT) in water, and served as a carrier for MWCNT conductive networks, which showed a tensile strength of 63.86 MPa and a conductivity of 15.63 S/m. The composite film exhibited potential applications in real-time monitoring of pressure sensing. [Display omitted] • DES pretreatment was employed under mild condition at 90 ℃. • Ultrasonication treatment obtained highly entangled LCNF from walnut shells. • LCNF provides viscosity of 0.44 Pa·s at 20 s-1 and ζ-potential of 17.65 mV. • Film with tensile strength of 63.86 MPa and conductivity of 15.63 S/m was obtained. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) processed into conductive films by liquid phase deposition technologies reveal increasing interest as electrode components in electrochemical device platforms for sensing and energy storage applications. In this work we show that the addition of acrylic latex to water-based CNT inks not only favors the fabrication of stable and robust flexible electrodes on plastic substrates but, moreover, sensitively enables the control of their electrical and electrochemical transport properties. Importantly, within a given concentration range, the acrylic additive in the films, being used as working electrodes, effectively blocks undesired faradaic transfer reactions across the electrode–electrolyte interface while maintaining their capacitance response as probed in a three-electrode electrochemical device configuration. Our results suggest a valuable strategy to enhance the chemical stability of CNT film electrodes and to suppress non-specific parasitic electrochemical reactions of relevance to electroanalytical and energy storage applications.

Solution processable metallic nanomaterials present a convenient way to fabricate conductive structures, which are necessary in all electronic devices. However, they tend to require post-treatments to remove the bulky ligands around them to achieve high conductivity. In this work, we present a method to formulate a post-treatment free conductive silver nanowire ink by controlling the type of ligands around the silver nanowires. We found that bidentate ligands with a rigid molecular structure were effective in improving the conductivity of the silver nanowire networks as they could maximize the number of linkages between neighboring nanowires. In addition, DFT calculations also revealed that ligands with good LUMO to silver energy alignment were more effective. Because of these reasons, fumaric acid was found to be the most effective ligand and achieved a large reduction in sheet resistance of 70% or higher depending on the nanowire network density. The concepts elucidated from this study would also be applicable to other solution processable nanomaterials systems such as quantum dots for photovoltaics or LEDs which also require good charge transport being neighboring nanoparticles.

A dip coating system was projected and constructed to deposit a large range of thin films onto solid substrates. A microcontroller was used to control the deposition system. As an example of application multilayer graphene (MLG) films were deposited onto glass slices in order to obtain conductive films with relatively good light transmittance. The MLG flakes were obtained using natural graphite and isopropyl alcohol resulting in three dispersions treated in ultrasound for 30, 60 and 90 minutes, respectively. Using atomic force microscopy, UV-Vis spectrometry and an electrometer the film characterizations were performed. MLG flakes about 13 nm thick, 10 mµ2 of area were observed using AFM. In films obtained with 35 immersions the electrical resistance and the resistance sheet reached 1.8 kΩ and 1.9kΩ/square respectively. The light transmittance reached 10-20% while films obtained with dispersions treated for 60 and 90 minutes were electrically continuous. Thus, conductive films can be used in chemiresistor sensors, electrochemical and supercapacitors electrodes.

Generation of particle defects in semiconductor manufacturing is inevitable, but it has to be minimized to enhance IC yield. There are various causes for the generation of particle defects in different semiconductor manufacturing processes, such as diffusion, thin-film deposition, lithography, etch, and clean. In this paper, primary defect generation mechanisms in thin-film deposition processes, such as atomic layer deposition TiN, radio frequency physical vapor deposition Ti, and physical vapor deposition TiN, are discussed. Various strategies, such as periodic clean optimization, on-load clean, idle pasting, periodic pasting optimization, kit life optimization, target burning optimization, and kit hardware selection that reduce the generation of defects in the thin-film deposition processes are presented. This paper also discusses hardware-induced surface defect and solutions to reduce them. [ABSTRACT FROM AUTHOR]

Low‐cost and high yield silver nanorings with the uniform ring diameter of 15±5 μm and thickness of 120±20 nm were synthesized via a simple solvothermal method. Based on our knowledge, this is the first time that a solvothermal method is used to prepare silver nanorings. Herein, by using ammonium salts as additive salts in the presence of pressure (150 kPa) inside the reactor, the reproducibility and yield of nanorings increased. The prepared silver nanorings easily dispersed in ethanol and have been coated by spray method on PET substrate to make flexible transparent conductive films (TCF). The film based on nanorings was shown better opto‐electrical properties (higher transparency with lower haze) in comparison with nanowires with higher aspect ratio and lower thickness, at the same sheet resistance (Rs). These results introduce silver nanorings as outstanding candidates for optoelectronics applications. Put a ring on it: Silver nanorings with high purity in high yield with uniform diameter and thickness were synthesized through facile solvothermal method. The conductive ink based on silver nanorings was successfully prepared and coated on PET substrate. The opto‐electrical properties of TCF with nanorings were improved in comparison with TCF with nanowires at the same sheet resistance (see figure). [ABSTRACT FROM AUTHOR]

Abstract: Exploiting biomass has raised great interest as an alternative to the fossil resources for environmental protection. In this respect, polyethylene furanoate (PEF), one of the bio‐based polyesters, thus reveals a great potential to replace the commonly used polyethylene terephthalate (PET) on account of its better mechanical, gas barrier, and thermal properties. Herein, a bio‐based, flexible, conductive film is successfully developed by coupling a PEF plastic substrate with silver nanowires (Ag NWs). Besides the appealing advantage of renewable biomass, PEF also exhibits a good transparency around 90% in the visible wavelength range, and its constituent polar furan moiety is revealed to enable an intense interaction with Ag NWs to largely enhance the adhesion of Ag NWs grown above, as exemplified by the superior bending and peeling durability than the currently prevailing PET substrate. Finally, the efficiency of conductive PEF/Ag NWs film in fabricating efficient flexible organic thin‐film transistor and organic photovoltaic (OPV) is demonstrated. The OPV device achieves a power conversion efficiency of 6.7%, which is superior to the device based on ITO/PEN device, manifesting the promising merit of the bio‐based PEF for flexible electronic applications. [ABSTRACT FROM AUTHOR]

Focusing on the interplay between interface chemistry, electrochemistry, and integrated electronics, we show a novel low-cost and flexible biosensing platform for continuous glucose monitoring. The amperometric biosensing system features a planar three-electrode structure on a plastic substrate, and a wireless near-field communication-powered electronic system performing sensor analog front-end, A/D conversion, digital control, and display tasks. The working electrode is made of electropolymerized poly (3,4-ethylenedioxythiophene) film onto a polyethylene terephthalate/gold electrode followed by immobilization of cross-linked glucose oxidase by glutaraldehyde. The advantages offered by such a device, including low-cost materials and instrumentation as well as the good sensitivity of 9.24 \mu \textA/(\mathrm mM \cdot \mathrm cm^2) are promising tools for point-of-care monitoring. It is demonstrated that the devices are good candidates for the development of advanced sensing approaches based on the investigation of the noise produced during operation (fluctuation-enhanced sensing). [ABSTRACT FROM PUBLISHER]

Polyethylene oxide (PEO)/polyvinyl chloride (PVC) blends with 2.5-10 wt% polyaniline (PAni) loadings were fabricated with and without the presence of ferric chloride (FeCl3). PEO/PVC/PAni and PEO/PVC/PAni-FeCl3 conductive films were prepared by solution casting method using tetrahydrofuran as the solvent at ambient temperature. The tensile properties, electrical conductivity and structure/morphology of the conductive films were analysed and discussed in this paper. The results indicated that the tensile strength and elongation at break decreased but the Young's modulus increased with PAni loading. Meanwhile, PEO/PVC/PAni-FeCl3 conductive films showed lower tensile strength and Young's modulus but higher elongation at break in comparison with PEO/PVC/PAni conductive films. The agglomeration of PAni at higher loadings was revealed by SEM study. However, this study found that higher loading of PAni increased the electrical conductivity of the films and further improved with the addition of FeCl3. The FTIR study revealed the structure of the films with the effect of PAni as filler and FeCl3 as the oxidising agent. [ABSTRACT FROM AUTHOR]

Here, environmental polyaniline graft epoxy-functionalized poly(vinyl alcohol) (PANI-g-EPVA) nanocomposites of enhanced storage stability and performance were obtained by building chemical bonds between PANI and PVA based on graft polymerization, using water as the medium. The performance of PANI-g-EPVA greatly depended on the epoxy content in PVA chains. With the increasing of the epoxy content, the morphology of colloidal particles changed from inhomogeneous spherical morphology to uniform rice-like morphology; the particle size decreased from 1333 to 153.9 nm; the turbiscan stability index (TSI) increased and the increasing rate of TSI dropped by 0.08 with time, certifying the enhanced storage stability. With incorporating appropriate amount of epoxy groups, PANI was able to distribute uniformly in nanocomposites and films with smooth morphology were obtained. As a result, the tensile strength increased from 24 to 64 MPa, the elongation at break rose from 51 to 166%, and the conductivity increased from 0.4 to 7.3 S/cm. The as-prepared waterborne PANI-g-EPVA nanocomposites can be well dispersed in waterborne epoxy resin to produce anticorrosive coatings. Subsequently, the corrosion current density decreased by two orders and the corrosion potential shifted from −0.67 to −0.54 V, demonstrating improved anticorrosive properties. [ABSTRACT FROM AUTHOR]

An aqueous suspension of a reduced composite of graphene oxide and humic acid has been prepared and used as ink to print conductive films and electrodes for supercapacitors. The dry powders of the composite ink before and after hydrazine reduction were characterized by IR and Raman spectroscopies and XPS. The surface areas of the reduced composite measured using the Brunauer-Emmett-Teller (BET) and standard contact porosimetry (SCP) methods were 6.5 and 200 m 2 /g, respectively. Moreover, the composite thin films obtained by printing exhibited island-like character. Further, the specific capacitance and other electrochemical properties of the supercapacitor using the composite electrode were studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrokinetic phenomena are studied using ethoxylated surfactant as charging agent. • Electrophoretic concentration of silver nanoparticles with high extraction was carried out. • Films with high purity and electrical conductivity was prepared by heat treatment. Linear electrophoresis in silver organosols was investigated in this work. Silver nanoparticles were obtained in reverse micelles of the nonionic ethoxylated surfactant Ecosurf SA4. Electrokinetic phenomena in media with low dielectric permittivity are described for the first time for this class of surfactants. The study of the composition of this surfactant showed weakly bound chlorine. This allowed us to propose a mechanism for the stabilization of charged particles similar to the action of solvating nonpolar solvents like chloroform. This mechanism differs from that previously described for the case of both ionic and nonionic surfactants. The dependence of the electrokinetic ζ -potential of nanoparticles on the concentration of surfactant is investigated. Electrophoretic concentration with close to quantitative degree of extraction was carried out for the systems with a maximum ζ -potential value. Silver content in the concentrate is up to 1.9 mol L−1. Thermal treatment allows getting films with a silver content of up to 97% and a conductivity of up to 20 µOhm/□. [ABSTRACT FROM AUTHOR]

Printed electronics is being explored as a rapid, facile means for manufacturing thermoelectric generators (TEGs) that can recover useful electrical energy from waste heat. This work examines the relevant electrical conductivity, thermal resistance, thermovoltage, and Seebeck coefficient of printed films for use in such printed flexible TEGs. The thermoelectric performance of TEGs printed using commercially relevant nickel, silver, and carbon inks is evaluated. The microstructure of the printed films is investigated to better understand why the electrical conductivity and Seebeck coefficient are degraded. Thermal conduction is shown to be relatively insensitive to the type of metalized coating and nearly equivalent to that of an uncoated polymer substrate. Of the commercially available conductive ink materials examined, carbon-nickel TEGs are shown to exhibit the highest thermovoltage, with a value of 10.3 μV/K. However, silver-nickel TEGs produced the highest power generation of 14.6 μW [from 31 junctions with temperature difference (Δ T) of 113°C] due to their low electrical resistance. The voltage generated from the silver-nickel TEG was stable under continuous operation at 275°C for 3 h. We have also demonstrated that, after a year of storage in ambient conditions, these devices retain their performance. Notably, the electrical conductivity and Seebeck coefficient measured for individual materials were consistent with those measured from actual printed TEG device structures, validating the need for further fundamental materials characterization to accelerate flexible TEG device optimization. [ABSTRACT FROM AUTHOR]

Highly conductive silver patterns that can be cured at low temperatures were achieved by proper selection of the kinds of amines in the formulation of metal organic decomposition (MOD) ink. The inks were synthesized via a complexing reaction between silver tartrate and various amines in ethyl alcohol solvent. Four monoamines and two diamines with increased carbon chain lengths were used. The kinds of amines affected the thermal decomposition temperature of silver ink as well as the sheet resistance and microstructure of the obtained silver films significantly. The film from 1,2-diaminopropane ink showed the lowest resistance and uniform surface morphology among all the inks developed. The microstructural evolution of the cured silver films was well correlated with the formulations of the inks. The underlying mechanism was discussed. The ink formulations were further elaborated by proper selection of Ag/NH 2 molar ratios. Highly conductive silver films with excellent flexible stability and great adhesion were achieved using optimized silver MOD inks. [ABSTRACT FROM AUTHOR]

The electrical resistance tomography (ERT) technique is applied to the measurement of sheet conductance maps of both uniform and patterned conductive thin films. Images of the sheet conductance spatial distribution and local conductivity values are obtained. Test samples are tin-oxide films on glass substrates, with electrical contacts on the sample boundary. Some samples are deliberately patterned in order to induce null conductivity zones of known geometry, while others contain higher conductivity inclusions. Four-terminal resistance measurements among the contacts are performed with a scanning setup. The ERT reconstruction is performed by a numerical algorithm based on the total variation regularization and the $L$ -curve method. ERT correctly images the sheet conductance spatial distribution of the samples. The reconstructed conductance values are in good quantitative agreement with independent measurements performed with the van der Pauw and the four-point probe methods. [ABSTRACT FROM AUTHOR]

In this paper, a chip-in-flex (CIF) assembly that has an excellent bending performance, including a minimum bending radius without a chip fracture and the capacity to withstand dynamic bending, is developed. Chip-on-flex (COF) and CIF assemblies are fabricated using anisotropic conductive films (ACFs) as interconnection materials. The COF package is composed of 40- \mu \textm -thin silicon chips, ACF, and flexible substrates. The CIF package is fabricated by attaching a cover adhesive film and a polyimide film on the COF package to encapsulate the silicon chip. Through static bending tests, the optimal thickness of the cover adhesive film is established. The optimized CIF assembly allows a minimum bending radius of 4 mm without a chip fracture, while the chip in the COF assembly fractures at a bending radius of 10 mm. A finite-element analysis of the static bending test is performed to understand the internal stress state of the assemblies. A bending reliability test of the CIF package is also conducted at a bending radius of 7.5 mm for 160k cycles, by measuring the daisy-chain resistance during the test. The effect of the elastic modulus of the ACF resin on the fatigue endurance is investigated through the bending fatigue test. The higher modulus of the ACF resin resulted in excellent fatigue reliability with stable ACF joints showing neither delamination nor resin crazing after 160k cycles of bending. [ABSTRACT FROM PUBLISHER]

The present work describes the preparation and characterization of PEDOT films (different commercial screen-printing grades) mixed with intrinsically conductive materials such as graphene, graphite, silver nanowires or AZO (antimony doped zinc oxide) deposited on plastic and paper substrates using screen-printing. The final objective was to develop a material that could be used both as electrochromic material and as electrode (electrically conductive) for use in electrochromic devices, avoiding the use of an extra layer of conductive material such as a TCO, allowing the use of different substrates, shapes or sizes, because of the limitations found in TCO deposition. The resulting films were characterized in terms of electrical and optical properties, as well as electrochemical stability. Techniques such as cyclic voltammetry, UV–visible spectroscopy, scanning electron microscopy and mechanical tests were also used. Electrochromic devices (ECDs) were assembled using these PEDOT based electrodes. The performances of the resulting devices (3 layer structures) were compared with that of conventional ones (5 layer structures) through the analysis of the device color contrast over time during continuous operation conditions using a cycling program. [ABSTRACT FROM AUTHOR]

In this paper, a particle-free MOD ink (MOD = metal–organic-decomposition) of high silver content was directly used for inkjet printing silver conductive patterns on PI substrate. The ink was synthesized by using silver oxalate as precursor, ethylamine as a complexing ligand, ethyl alcohol and ethylene glycol as the solvent. The chemical and physical properties of the solution ink were investigated. The MOD ink has 27.6 wt.% of silver. The deposited films on PI substrate were thermally treated at a range of temperatures and times, and then analyzed in terms of their morphology and resistivity. The silver film cured at 170 °C for 30 min had a resistivity of 8.4 μΩ·cm. The printed patterns on PI substrate cured at 150 °C for 30 min showed metalized silver with low resistivity (8.6 μΩ·cm), high reflection, and good adhesion. [ABSTRACT FROM AUTHOR]

In-situ generation of a nanodispersed conductive polymer within a polypropylene matrix has been pursued in order to obtain flexible, conductive films. Radiation grafting of acrylic acid to polypropylene (PP) has been applied to insert carboxyl functionalities on PP. The radiation-grafted films have been further derivatized with a variety of diamines and used as substrates for in-situ chemical oxidative polymerization of polyaniline (PANI). PANI grows as a thin skin from the surface of the film as well as an interpenetrated network in its interiors. Evidence of chemical attachment of PANI to PP has been sought by performing FTIR and XPS analyses after extraction of the unbound polymer. The influence of the nature of the substituent attached to PP on the optical and electrical properties of the films has been investigated. PANI-PP skin-core films have been also tested as flexible electrodes for further electrochemical growth of the conductive polymer. [ABSTRACT FROM AUTHOR]