The next-generation application of pressure sensors is gradually being extended to include electronic artificial skin (e-skin), wearable devices, humanoid robotics and smart prosthetics. In these advanced applications, high sensing capability is an essential feature for high performance. Although surface patterning treatments and some special elastomeric interlayers have been applied to improve sensitivity, the process is complex and this inevitably raises the cost and is an obstacle to large-scale production. In the present study a simple printing process without complex patterning has been used for constructing the sensor, and an interlayer is employed comprising elastomeric composites filled with silver nanowires. By increasing the relative permittivity, εr, of the composite interlayer induced by compression at high nanowire concentration, it has been possible to achieve a maximum sensitivity of 5.54 kPa(-1). The improvement in sensitivity did not sacrifice or undermine the other features of the sensor. Thanks to the silver nanowire electrodes, the sensor is flexible and stable after 200 cycles at a bending radius of 2 mm, and exhibits outstanding reproducibility without hysteresis under similar pressure pulses. The sensor has been readily integrated onto an adhesive bandage and has been successful in detecting human movements. In addition to measuring pressure in direct contact, non-contact pressures such as air flow can also be detected.

Self-organized, freestanding titania (TiO2) membrane with ultrahigh aspect ratio of the length/diameter (∼1500) was fabricated via electrochemical anodization of highly pure titanium (Ti) foil in fluorine-containing ethylene glycol, followed by a simple and safe detachment of the formed TiO2 membrane from the metallic Ti substrate. The resulting membrane consists of highly ordered, vertically aligned, one-side open TiO2 nanotube arrays. The pore diameter, wall thickness, and length of the nanotube arrays are 90 nm, 15 nm, and 135 µm, respectively, at a certain anodization condition.

Silver nanowires (AgNWs) have emerged as a promising nanomaterial for next generation stretchable electronics. However, until now, the fabrication of AgNWbased components has been hampered by complex and time-consuming steps. Here, we introduce a facile, fast, and one-step methodology for the fabrication of highly conductive and stretchable AgNW/polyurethane (PU) composite electrodes based on a high-intensity pulsed light (HIPL) technique. HIPL simultaneously improved wire-wire junction conductivity and wire-substrate adhesion at room temperature and in air within 50 μs, omitting the complex transfer-curing-implanting process. Owing to the localized deformation of PU at interfaces with AgNWs, embedding of the nanowires was rapidly carried out without substantial substrate damage. The resulting electrode retained a low sheet resistance (high electrical conductivity) of <10 Ω/sq even under 100% strain, or after 1,000 continuous stretching-relaxation cycles, with a peak strain of 60%. The fabricated electrode has found immediate application as a sensor for motion detection. Furthermore, based on our electrode, a light emitting diode (LED) driven by integrated stretchable AgNW conductors has been fabricated. In conclusion, our present fabrication approach is fast, simple, scalable, and costefficient, making it a good candidate for a future roll-to-roll process.

A suitable seawater adsorbent for extraction of uranium(vi) with a removal rate of up to 80%.

Transparent electrode based on silver nanowires (AgNWs) emerges as an outstanding alternative of indium tin oxide film especially for flexible electronics. However, the conductivity of AgNWs transparent electrode is still dramatically limited by the contact resistance between nanowires at high transmittance. Polyvinylpyrrolidone (PVP) layer adsorbed on the nanowire surface acts as an electrically insulating barrier at wire–wire junctions, and some devastating post-treatment methods are proposed to reduce or eliminate PVP layer, which usually limit the application of the substrates susceptible to heat or pressure and burden the fabrication with high-cost, time-consuming, or inefficient processes. In this work, a simple and rapid pre-treatment washing method was proposed to reduce the thickness of PVP layer from 13.19 to 0.96 nm and improve the contact between wires. AgNW electrodes with sheet resistances of 15.6 and 204 Ω sq−1 have been achieved at transmittances of 90 and 97.5 %, respectively. This method avoided any post-treatments and popularized the application of high-performance AgNW transparent electrode on more substrates. The improved AgNWs were successfully employed in a capacitive pressure sensor with high transparency, sensitivity, and reproducibility.Electronic supplementary materialThe online version of this article (doi:10.1007/s40820-014-0018-0) contains supplementary material, which is available to authorized users.

Rutile and anatase titanium dioxide (TiO(2)) powders were used as sonocatalysts for the degradation of methyl orange which was used as a model compound. Ultrasound was used as an irradiation source. It was found that the sonocatalytic degradation ratios of methyl orange in the presence of TiO(2) powder were much better than ones without any TiO(2), but the sonocatalytic activity of rutile TiO(2) particles was obviously higher than that of anatase TiO(2) particles. Although there are many factors influencing sonocatalytic degradation of methyl orange, the experimental results show that the best degradation ratio of methyl orange can be obtained when the experimental conditions of the initial methyl orange concentration of 10 mg/l, rutile TiO(2) added amount of 500 mg/l, ultrasonic frequency of 40 kHz, output power of 50 W, pH=3.0 and 40 degrees C within 150 min were adopted. In addition, the catalytic activity of reused rutile TiO(2) catalyst was also studied and found to be better than new rutile TiO(2) catalyst sometimes. All experimental results indicated that the method of the sonocatalytic degradation of organic pollutants in the presence of TiO(2) powder was an advisable choice for treating non- or low-transparent organic wastewaters.

A new strategy via coupling a polyol route with an oxidation process has been developed to successfully synthesize p-n junction CuO/BiVO4 heterogeneous nanostructures. The experimental results reveal that the as-prepared p-n junction CuO/BiVO4 heterogeneous nanostructures exhibit much higher visible-light-driven photocatalytic activity for the degradation of model dye rhodamine B (RhB) than the pure BiVO4 nanocrystals. The photocatalytic degradation rate (C/C0) of the RhB for p-n junction CuO/BiVO4 heterogeneous nanostructures is about two times higher than that of pure BiVO4 nanocrystals. The enhanced photocatalytic efficiency is attributed to a large number of p-n junctions in CuO/BiVO4 heterogeneous nanostructures, which effectively reduces the recombination of electrons and holes by charge transfer from n-type BiVO4 to the attached p-type CuO nanoparticles. This work not only provides an efficient route to enhance the visible-light-driven photocatalytic activity of BiVO4, but also offers a new strategy for fabricating p-n junction heterogeneous nanostructure photocatalysts, which are expected to show considerable potential application in solar-driven wastewater treatment and water splitting.

Synthesis of novel furan-containing tetrafunctional fluorene-based benzoxazine monomer and its high performance thermoset.