Photogeneration of silver nanoparticles induced by UV radiation and their use as a sensor for the determination of chloride in fuel ethanol using a flow-batch system

Photogeneration of silver chloride nanoparticles (AgCl-NPs) in fuel ethanol was used as a sensor for the spectrophotometric determination of chloride. A low-power UV radiation source (germicidal lamp) was placed close to a flow-batch chamber and a 3D-built support for the reaction chamber was used to couple fiber optic cables in the orthogonal direction with the UV-lamp beam, allowing the monitoring of nanoparticle formation in real-time using a spectrophotometer. The nanoparticles were characterized via high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and UV-vis spectroscopy. Most of the particles exhibited a spherical shape with an average diameter of 18 nm. The absorbance maximum was observed at 440 nm and was used for chloride determination in fuel ethanol. Under the optimized working conditions, the system exhibited a linear response from 0.05 to 0.8 mg L^-1 chloride, with a limit of detection (95%) and coefficient of variation (n = 8) were estimated to be 12 μg L^-1 chloride and 2.2%, respectively. The intra- and inter-day precisions (coefficient of variation) were 2.4% and 2.8%, respectively. This working range (0.05-0.8 mg L^-1) for the determination of chloride at low concentrations met the limit required by Brazilian legislation (limit of 1.0 mg kg^-1). Analyses of fuel ethanol were performed without sample treatment and the obtained results were compared with those obtained by ion-chromatography. No significant differences were observed between the two methods at the 95% confidence level.

Cohesively enhanced electrical conductivity and thermal stability of silver nanowire networks by nickel ion bridge joining

A facile method for producing high-performance nickel enhanced silver nanowire (Ag NW) transparent electrodes on a flexible substrate is reported. The modified electroplating method called enhanced nickel ion bridge joining of Ag NWs, which provides a new route for improving the loose junctions in bare Ag NW networks. The sheet resistance of Ag NW electrode drops from over 2000 Ω sq⁻¹ to 9.4 Ω sq⁻¹ with excellent thermal uniformity after the electroplating process within 10 s. Nickel enhanced Ag NW transparent films are applied on flexible heaters with good thermal stability (165 °C for 2 h) and mechanical flexibility (3500 cycles under 2.5 mm bending radius) after mechanical bending process. Moreover, the mechanism of nickel growth is also confirmed that the nickel electroplating of the Ag NWs obeyed Faraday’s Laws.

In situ spectroscopic studies of the one-pot synthesis of composition-controlled Cu–Ni nanowires with enhanced catalytic activity

Development of a novel alcohol reduction technique for the one-pot synthesis of Cu–Ni NWs by elucidating the formation mechanism by using in situ spectroscopic measurements.

Determination of nitrite ions in environment analysis with a paper-based microfluidic device

A new microfluidic paper-based analytical device, a (Ag-μPAD)-based chemiresistor composed of silver ink, has been developed for the selective, sensitive, and quantitative determination of nitrite ions in environmental analysis.

Synthesis and optoelectronic characteristics of 20 nm diameter silver nanowires for highly transparent electrode films

We demonstrate the polyol synthesis of ultrathin Ag nanowires with diameters of 20 nm and an aspect ratio as high as ∼1000 under high-pressure conditions.

Salt-mediated polyol synthesis of silver nanowires in a continuous-flow tubular reactor

Silver nanowires were successfully synthesized by a polyol reduction method in a continuous-flow reactor with a yield of 2 g h⁻¹.

Synthesis of Ag–Ni core–shell nanowires and their application in anisotropic transparent conductive films

Transparent conductive films with high anisotropic conductivity ratio (>10⁵) were prepared from Ag–Ni core–shell nanowires by applying a magnetic field.

Transparent conductive silver nanowire electrodes with high resistance to oxidation and thermal shock

Silver nanowire electrodes incorporated with polyethoxysiloxane reveal excellent resistance to oxidation and significantly increase conductivity by 1–2 orders of magnitude.

Degenerate quasicrystal of hard triangular bipyramids

We report a degenerate quasicrystal in Monte Carlo simulations of hard triangular bipyramids each composed of two regular tetrahedra sharing a single face. The dodecagonal quasicrystal is similar to that recently reported for hard tetrahedra [Haji-Akbari et al., Nature (London) 462, 773 (2009)] but degenerate in the pairing of tetrahedra, and self-assembles at packing fractions above 54%. This notion of degeneracy differs from the degeneracy of a quasiperiodic random tiling arising through phason flips. Free energy calculations show that a triclinic crystal is preferred at high packing fractions.

Shape changes in Au–Ag bimetallic systems involving polygonal Au nanocrystals to spherical Au/Ag alloy and excentered Au core Ag/Au alloy shell particles under oil-bath heating

Spherical Au/Ag alloy and excentered Au core Ag/Au alloy shell particles were prepared using shape changes in Au–Ag bimetallic systems involving polygonal Au nanocrystals under oil-bath heating.

Silver nanowires--unique templates for functional nanostructures

This feature article reviews the synthesis and application of silver nanowires with the focus on a polyol process that is capable of producing high quality silver nanowires with high yield. The as-synthesized silver nanowires can be used as both physical templates for the synthesis of metal/dielectric core/shell nanowires and chemical templates for the synthesis of metal nanotubes as well as semiconductor nanowires. Typical examples including Ag/SiO(2) coaxial nanocables, single- and multiple-walled nanotubes made of Au-Ag alloy, AgCl nanowires and AgCl/Au core/shell nanowires are discussed in detail to illustrate the versatility of nanostructures derived from silver nanowire templates. Novel properties associated with these one-dimensional nanostructures are also briefly discussed to shed the light on their potential applications in electronics, photonics, optoelectronics, catalysis, and medicine.