In-Situ Oxidative Polymerization of Pyrrole Composited with Cellulose Nanocrystal by Reactive Ink-Jet Printing on Fiber Substrates.

A simple and novel method for the deposition of polypyrrole (PPy) and cellulose nanocrystal (CNC) composites on different fiber substrates by reactive ink-jet printing was proposed. PPy/CNCs composites were successfully prepared, and the surface resistance of conductive layer deposited on different fiber substrates is the least when the monomer concentration is 0.6 M. PPy/CNCs were deposited on polyethylene terephthalate (PET) to form a conductive layer by adding polyvinyl alcohol (PVA), and the optimum sintering temperature is 100 °C (monomer/PVA ratio 4.0, conductivity 0.769 S cm-1). The PPy/CNCs conductive layer deposited on the paper has the lowest surface resistance and the best adhesion, and the surface resistance of PPy/CNCs conductive layer decreases first and then increases with the increase of sulfonate concentration. Moreover, the volume of anion in sulfonate will affect the arrangement and aggregation of PPy molecular chain in composite materials. Appropriate sulfonate doping can improve the conductivity and stability of conductive paper, and the maximum conductivity is 0.813 S cm-1. Three devices based on PPy/CNCs conductive paper were proposed and fabricated. Therefore, this ink-jet printing provides a new method for the preparation of conductive materials, sensors, energy storage and electromagnetic shielding, etc.

A Review: Preparation, Performance, and Applications of Silicon Oxynitride Film.

Silicon oxynitride (SiNxOy) is a highly promising functional material for its luminescence performance and tunable refractive index, which has wide applications in optical devices, non-volatile memory, barrier layer, and scratch-resistant coatings. This review presents recent developments, and discusses the preparation methods, performance, and applications of SiNxOy film. In particular, the preparation of SiNxOy film by chemical vapor deposition, physical vapor deposition, and oxynitridation is elaborated in details.

Nano-Silver Ink of High Conductivity and Low Sintering Temperature for Paper Electronics.

Highly conductive ink with low sintering temperature is important for printed electronics on paper substrate. Silver nanoparticles (Ag NPs) of different average radii ranging from 48 to 176 nm were synthesized by adjusting the Ag+ concentration in the reaction process. The electric resistivity of the Ag NP-based ink film in relation to Ag NP size, sintering temperature, amount of PVP capping agent on Ag NP surface, and morphology evolution of the film during heating process was investigated. It was found that the resistivity of the films reduced very rapidly with increasing particle size due above all to reduced amount of protective agent capping on the Ag NPs. A semi-empirical relationship between the resistivity and the particle size was proposed. With the help of this mathematical expression, one gains both systematic and detailed insight to the resistivity evaluation with regard to the Ag particle size. The optimal electric resistivity of 4.6 µΩ cm was achieved at 140 °C for 10 min which was very close to the resistivity value of bulk Ag (1.58 µΩ cm). Mechanical flexibility of the printed electronics with the Ag NP-based ink on paper substrates was investigated. The prints on the art coated paper exhibited better flexibility compared to that on the photopaper. This might be attributed to the surface coating composition, surface morphology of the paper, and their corresponding ink absorption property.

Synthesis and Applications of Silver Nanowires for Transparent Conductive Films.

Flexible transparent conductive electrodes (TCEs) are widely applied in flexible electronic devices. Among these electrodes, silver (Ag) nanowires (NWs) have gained considerable interests due to their excellent electrical and optical performances. Ag NWs with a one-dimensional nanostructure have unique characteristics from those of bulk Ag. In past 10 years, researchers have proposed various synthesis methods of Ag NWs, such as ultraviolet irradiation, template method, polyol method, etc. These methods are discussed and summarized in this review, and we conclude that the advantages of the polyol method are the most obvious. This review also provides a more comprehensive description of the polyol method for the synthesis of Ag NWs, and the synthetic factors including AgNO3 concentration, addition of other metal salts and polyvinyl pyrrolidone are thoroughly elaborated. Furthermore, several problems in the fabrication of Ag NWs-based TCEs and related devices are reviewed. The prospects for applications of Ag NWs-based TCE in solar cells, electroluminescence, electrochromic devices, flexible energy storage equipment, thin-film heaters and stretchable devices are discussed and summarized in detail.

Silver Nanoparticles Based Ink with Moderate Sintering in Flexible and Printed Electronics.

Printed electronics on flexible substrates has attracted tremendous research interest research thanks its low cost, large area production capability and environmentally friendly advantages. Optimal characteristics of silver nanoparticles (Ag NPs) based inks are crucial for ink rheology, printing, post-print treatment, and performance of the printed electronics devices. In this review, the methods and mechanisms for obtaining Ag NPs based inks that are highly conductive under moderate sintering conditions are summarized. These characteristics are particularly important when printed on temperature sensitive substrates that cannot withstand sintering of high temperature. Strategies to tailor the protective agents capping on the surface of Ag NPs, in order to optimize the sizes and shapes of Ag NPs as well as to modify the substrate surface, are presented. Different (emerging) sintering technologies are also discussed, including photonic sintering, electrical sintering, plasma sintering, microwave sintering, etc. Finally, applications of the Ag NPs based ink in transparent conductive film (TCF), thin film transistor (TFT), biosensor, radio frequency identification (RFID) antenna, stretchable electronics and their perspectives on flexible and printed electronics are presented.

A gold nanoparticle ink suitable for the fabrication of electrochemical electrode by inkjet printing.

Inkjet printing is a non-contact and low-cost method for high resolution deposition of nanomaterials and mass production of electro-devices. In this study, an environmentally friendly gold nanoparticles (AuNPs) ink was prepared and electrochemical electrodes were fabricated through inkjet printing technology. Electrochemical behaviors of the printed electrodes with different printing layers and laser sintering intensities were studied by cyclic voltammetry. Electrode sintered at 0.6 A with double layers showed a good reproducibility and well linear relation in voltammetric measurement of potassium ferricyanide. Moreover, the prepared electrode was found to be effective for formaldehyde electro-oxidation in alkaline medium. The above results indicated that this AuNPs ink, which can be facilely prepared, may have great potential applications for the preparation of flexible and low-cost electrochemical sensing devices and biosensors by inkjet printing.

Controlled inkjetting of a conductive pattern of silver nanoparticles based on the coffee-ring effect.

Conductive patterns with line widths of 5-10 µm are successfully fabricated by utilizing the coffee-ring effect in inkjet printing, resulting in transmittance values of up to 91.2% in the visible to near-infrared region. This non-lithographic approach broadens the range of fabrication procedures that can be used to create various nanoparticle-based microstructures and electronic devices.

Continuous microwire patterns dominated by controllable rupture of liquid films.

Controllable microwire patterns are prepared by dominating the rupture of liquid films. Regular rhombic-shaped micropillar arrays serve as wetting defects to pin or depin liquids, yielding continuous, herringbone, bead-shaped polystyrene microwire patterns or bead arrays. The results provide a deeper understanding of the controllable rupture of liquid films and offer a general strategy for the organization of polymers into structures needed for wiring, interconnects, and functional devices for future microfabrication.

Synthesis of monodisperse silver nanoparticles for ink-jet printed flexible electronics.

In this study, monodisperse silver nanoparticles were synthesized with a new reduction system consisting of adipoyl hydrazide and dextrose at ambient temperature. By this facile and rapid approach, high concentration monodisperse silver nanoparticles were obtained on a large scale at low protectant/AgNO(3) mass ratio which was highly beneficial to low cost and high conductivity. Based on the synthesized monodisperse silver nanoparticles, conductive inks were prepared with water, ethanol and ethylene glycol as solvents, and were expected to be more environmentally friendly. A series of electrocircuits were fabricated by ink-jet printing silver nanoparticle ink on paper substrate with a commercial printer, and they had low resistivity in the range of 9.18 × 10( - 8)-8.76 × 10( - 8) Ω m after thermal treatment at 160 °C for 30 min, which was about five times that of bulk silver (1.586 × 10( - 8) Ω m). Moreover, a radio frequency identification (RFID) antenna was fabricated by ink-jet printing, and 6 m wireless identification was realized after an Alien higgs-3 chip was mounted on the printed antenna by the flip-chip method. These flexible electrocircuits produced by ink-jet printing would have enormous potential for low cost electrodes and sensor devices.

The research of manufacture of flexible conductive tracks at room temperature.

Nano silver is widely used in conductive lines for its advantages, nano size, low melt temperature and excellent conductivity. In general, nano silver of less than 50 nm need be sintered at 200 centigrade in order to acquire conductivity, but it limits the choice of the substrates, only high temperature resistant substrate can be used, for example, PI film and glass. In order to acquire flexible tracks with excellent conductivity at room temperature on paper and PET, nano silver emulsion of 2 percent silver content was prepared through liquid phase chemical reduction, and then the concentration of silver was improved to 17 percent by centrifuging at high speed. And the emulsion was adjusted to meet the demand of inkjet printing, such as surface tension, and viscosity, pH value, then was jetted onto photo paper and PET film. High conductivity was acquired after treated by 830 nm infrared laser, and the sheet resistance is less than 2 omega/(see symbol). After aging test, the conductivity was stable. The method can be used in solar cells, flexible LED, intelligent packaging and can replace the traditional screen printing method at low cost.