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The investigation of hydrogen oxidation reaction (HOR) in alkaline conditions has been the subject of a wide interest in the past few years with the rise of alkaline membrane fuel cells (AMFCs). In particular, the quest for the lowest content of platinum group metals (PGMs) in the HOR catalyst is ongoing. In this article, we propose the use of a nanoscale Pd layer partially covering a Ni film to provide the most efficient use of the PGM in the HOR catalyst. The Pd/Ni electrodes were prepared by spontaneous and electrolytic deposition of Pd onto smooth polycrystalline Ni surfaces with different surface compositions. The electrodes were characterized by cyclic voltammetry and atomic force microscopy. Electrocatalytic activity in HOR of the Pd/Ni electrodes was measured in alkaline solution by rotating disc electrode method. In the manuscript, we demonstrate that a Pd coverage as low as 1.5% vs. Ni coverage is sufficient to provide a high current density compared to pure Ni. The current density linearly increases with the Pd coverage up to a Pd coverage of 17%; upon further increase in the Pd coverage, the current density reaches a plateau, i.e. the diffusion limit for the HOR process.The comparison with Pd supported on carbon shows the clear benefit for the bimetallic catalyst.

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The adsorption layer of the nonionic surfactant triethoxy monooctylether C8E3 has been investigated at the free water surface by means of both experimental and computer simulation methods. The surface tension of the aqueous solution of C8E3 has been measured by pendant drop shape analysis in the entire concentration range in which C8E3 is soluble in water. The data obtained from these measurements are used to derive the adsorption isotherm. The critical micellar concentration and the surface excess concentration of the saturated adsorption layer are found to be 7.48 mM and 4.03 micromol/m2, respectively, the latter value corresponding to the average area per molecule of 41 A2. In order to analyze the molecular level structure of the unsaturated adsorption layer, Monte Carlo simulations have been performed at four different surface concentration values, i.e., 0.68, 1.36, 2.04, and 2.72 micromol/m2, respectively. It has been found that the water surface is already almost fully covered at the lowest surface density value investigated, and the adsorbed molecules show a strong preference for lying parallel with the interface in elongated conformations. No sign of the penetration of the hydrophilic triethoxy headgroups into the aqueous phase to any extent has been observed. With increasing surface densities the preferential orientation of the apolar octyl tails gradually turns from lying parallel with the interface to pointing toward the vapor phase by their CH3 end, whereas the conformation of the adsorbed molecules becomes gradually less elongated. Both of these changes lead to the increase of the number of C8E3 molecules being in a direct contact (i.e., forming hydrogen bonds) with water. However, the increasing number of the C8E3 molecules hydrogen bonded to water is found to be accompanied by the weakening of this binding, i.e., the decrease of both the number of hydrogen bonds a bound C8E3 molecule forms with water and the magnitude of the average binding energy of the adsorbed C8E3 molecules.

2 pH and CO 2 sensing by curcumin coloured cellophane test strip ABSTRACTCurcumin coloured cellophane test strip -fabricated without any synthetic material -is used to determine in situ the instantaneous pH changes in liquids and in the air. A low cost, portable sensor array for possible medical and food-industrial application is developed. Next to the pH detection, curcumin coloured test strip can be applied as CO 2 monitoring sensor, too. On-going processes and the structural changes are followed by UV-VIS spectrophotometer, ATR-FTIR and AFM.

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In this manuscript, the formation of nickel nanowires (average size: several tens to hundreds of µm long and 1.0-1.5 µm wide) at low temperature is found to be driven by dewetting of liquid organometallic precursors during spin coating process and by self-assembly of Ni clusters. Elaboration of metallic thin films by low temperature deposition technique makes the preparation process compatible with most of the substrates. The use of iron and cobalt precursor shows that the process could be extended to other metallic systems. In this work, AFM and SEM are used to follow the assembly of Ni clusters into straight or zigzag lines. The formation of zigzag structure is specific to the Ni precursor at appropriate preparation parameters. This template free process allows a control of anisotropic structures with homogeneous sizes and angles on standard Si/SiO 2 surface.

13Concern on different food colours has a rising tendency in the last decades. Many times the 14 labelled ingredients of a food product don't reflect the real composition. To expose products The presence of synthetic dyes in food shows a potential health risk, as several diseases 35(allergy, asthma, hyperactivity and even cancer) are directly linked to the use of these colours Cellophane, which is a thin, transparent, regenerated cellulose film produced from sodium 52 cellulose xanthate (Laity et al. 2000), has been an important industrial material for many 53 years. It is a well-known hydrophilic, water insoluble natural polymer -this property is 54 related to its crystallinity and the intermolecular hydrogen bonding between its hydroxyl 55 groups (Tome et al. 2011; Canas et al. 2002). 56It is used as packaging material for food and confectionary products (candies, cheese and 57 baked goods), and due to its good mechanical properties and hydrophilicity it finds 58 applications in industry (membranes for batteries) (Tome et al. 2011;Beach et al. 2000), and 59 medicine (semipermeable membranes for haemodialysis -since cellophane allows the 60 diffusion of ions and low molecular weight solutes but it does not permit the diffusion of 61 proteins or high molecular weight macromolecules) (Tome et al. 2011; Canas et al. 2002). 62Although nowadays its pre-eminence in the packaging industry has been largely superseded 63 by the oriented polypropylene film, cellophane still has special uses due to its physical 64 properties, which confer advantages compared to other polymers (Laity et al. 2000). 66Compared to cellulose, it has a differentiated 'skin-core' layer structure, with relatively thin, 67 dense skin on both side of the thicker, porous core (Fig. 1A). The swelling of cellophane in 68 water is well known, reaching equilibrium within a period of 2 hours, with no further changes 69 in dimensions. The thickness of the cellophane is 26 ± 1μm as received, 68 ± 2μm fully 70 swollen with water (Laity et al. 2000). 72Cellophane is transparent both to ordinary and UV-light; it exhibits the anisotropic properties 73 of cellulose due to its two optical axes and it has excellent dielectric properties. Per se it is not 76The goal of the present study is to build a quick, qualitative food colour test method using the ,3,3-trimethyl-2-[(1E,3E,5E,7E,9E,11E,13E,15E, 17E)-3,7,12,16-tetramethyl-18-(2,6,6-trimethylcyclohexen-1-yl)octadeca-1,3,5,7,9,11,13, 15,17-nonaenyl] The tested foods, beverages and special colours are listed in Table 3. Food products as soups colours the test strip, too (Fig. 1). The colouring effect is based on physisorption of the dye molecules in the swelled cellophane 146 capillaries ( Fig. 1Ab and 1Ac). Authors conjecture that the differences in the chemical 187 trisodium (4E)-5-oxo-1-(4-sulfonatophenyl)-4-[(4-sulfonatophenyl)hydrazono]-3-pyrazolecarboxylateFirst instant soups are tested and the absorbance spectra are compared to absorption spectrum 188 of curcumin (Fig. 4) In both cases ...