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The effect of electron‐beam patterning on the water uptake and ionic conductivity of Nafion films using a combination of X‐ray photoelectron spectroscopy, quartz crystal microbalance studies, neutron reflectometry, and impedance spectroscopy is reported. The aim is to further characterize the nanoscale patterned Nafion structures recently used as a key element in novel ion‐to‐electron transducers by Gluschke et al. To enable this, the electron beam patterning process is developed for large areas, achieving patterning speeds approaching 1 cm2 h−1, and patterned areas as large as 7 cm2 for the neutron reflectometry studies. It is ultimately shown that electron‐beam patterning affects both the water uptake and the ionic conductivity, depending on film thickness. Type‐II adsorption isotherm behavior is seen for all films. For thick films (≈230 nm), a strong reduction in water uptake with electron‐beam patterning is found. In contrast, for thin films (≈30 nm), electron‐beam patterning enhances water uptake. Notably, for either thickness, the reduction in ionic conductivity arising from electron‐beam patterning is kept to less than an order of magnitude. Mechanisms are proposed for the observed behavior based on the known complex morphology of Nafion films to motivate future studies of electron‐beam processed Nafion. [ABSTRACT FROM AUTHOR]

Reported herein is a neutron reflectometry (NR) study on hydrated Nafion thin films (∼30 nm) on a silicon substrate with native oxide. The Nafion morphology is investigated systematically across the whole relative humidity range using both H2O and D2O vapours to enable a comparative study. By utilising this systematic approach two key results have been obtained. The first is that by leveraging the strong positive scattering signal from the D2O vapour, a complete and systematic water adsorption isotherm (Type II) for a Nafion thin film is produced. Utilising the slight negative scattering signal of the H2O enabled the quantification of the hydration dependent evolution of the formation of Nafion/water lamellae near the substrate surface. The number of lamellae layers increases continuously with hydration, and does not form abruptly. We also report the effects of swelling on the thin films across the relative humidity ranges. The work reported should prove useful in quantifying other hydration dependent properties of Nafion thin films such as conductivity and understanding Nafion/semiconductor based devices, as well as showcasing a NR methodology for other hydrophilic polymers. [ABSTRACT FROM AUTHOR]

Combination the materials together is a direct and forceful strategy to improve the electrochemical properties of each raw material. Herein, we present the method of hydrothermal process and treatment/calcination combination that is easy to synthesize a NiCo2O4 nanoparticles‐mesoporous carbon composite (C/NiCo2O4). The result study electrochemical properties of materials revealed that the C/NiCo2O4 composite has excellent electrochemical properties compare with pristine NiCo2O4 or carbon. In particular, maximum specific capacitance of C/NiCo2O4 material at a current density of 1 A.g−1 is 204.28 F.g−1, meanwhile the Cs of carbon and NiCo2O4 are 25.06 F.g−1 and 178.78 F.g−1, respectively. In addition, C/NiCo2O4 material also showed excellent capacitance retention, Cs maintained to 90.35% after 3000 charge‐discharge continuous cycles. The results show that the C/NiCo2O4 is a promising material for application as supercapacitor electrode. [ABSTRACT FROM AUTHOR]

Abstract: In this study, triethylsilylethynyl‐anthradithiophene (TES‐ADT) films with different density of grain boundaries are used for systematic investigation of effects of grain boundary density on gas sensing properties of TES‐ADT field‐effect transistors (FETs). Grain boundary density is simply controlled by changing mixing time of TES‐ADT solution. Higher mixing time leads to higher grain boundary density, and field‐effect mobility decreases with increased grain boundary density. However, gas sensing properties exhibit the opposite behavior. Drain current and field‐effect mobility of FETs based on TES‐ADT film with higher grain boundary density increase much more upon exposure of NO2 with electron withdrawing character. In addition, dynamic gas sensing tests reveal that response rate and sensitivity of a TES‐ADT sensor are enhanced remarkably by an increase of grain boundary density in TES‐ADT films. Grain boundaries provide a pathway for diffusion of gas molecules into channel regions and thus increase of grain boundary density is beneficial for development of highly sensitive OFET gas sensors. [ABSTRACT FROM AUTHOR]

Triethylsilylethynyl anthradithiophene (TES-ADT) has been shown to be a promising soluble semiconductor for the active layer of organic field-effect transistors (OFETs) due to its solution processability, chemical stability and excellent electrical properties. However, there are still some problems that need to be resolved for the utilization of TES-ADT in OFETs. One of these problems is a patterning issue to minimize crosstalk between neighboring TES-ADT FETs. To this end, TES-ADT crystals of various shapes need to be patterned at the desired positions. Here, we demonstrated a simple method to fabricate patterned TES-ADT crystals by using a PDMS mold containing 1,2–dichloroethane (DCE) solvent. This method serves the dual purpose of preparing a variety of pattern shapes while simultaneously changing as-spun TES-ADT thin films into crystal patterns. The top-contact OFETs with the TES-ADT crystal patterns exhibited high performance, reaching a field-effect mobility of ∼0.3 cm 2 V −1 s −1 . [ABSTRACT FROM AUTHOR]