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[en] During the current contract period, the variation of coordination number of tervalent lanthanides observed earlier with 8-quinolinol extraction systems was exploited in the development of mixed ligand (so-called synergistic) extraction systems involving 1, 10-phenanthroline (phen) and 8-quinolinol (HOx). Using a mixture of HOx and phen significantly enhanced the difference between adjacent lanthanide ions and facilitated their separation
[en] Vibrational spectra of lanthanide oxines have been measured in the far-infrared region. In addition, the similar yttrium complex was investigated for further experimental evidence for the proposed band assignments. The most important metal-oxygen and metal-nitrogen bond vibrations have been attributed to absorptions between 390-350cm-1 and 210-170cm-1, respectively. (Author)
[en] The on-line incorporation of cloud point extraction (CPE) with/without 8-hydroxyquinoline (8-Ox) as chelating agent into flow injection analysis associated with inductively coupled plasma optical emission spectrometry (ICP-OES) for determining trace rare earth elements (REEs) is presented and evaluated. The significant parameters affecting on-line cloud point extraction of REEs such as sample pH, flow rate, 8-Ox concentration, Triton X-114 concentration were systematically studied. Under the optimized conditions, with the consumption of 3.0 mL sample solution, the limits of detection (3σ) were ranged from 41.4 pg mL-1 (Yb) to 448 pg mL-1 (Gd) with relative standard deviations (RSDs) of 1.0% (Eu)-5.9% (Sm) for on-line CPE-ICP-OES with 8-Ox as chelating agent, and 69.0 pg mL-1 (Sc) to 509.5 pg mL-1 (Sm) with RSDs of 2.9% (Yb)-7.5% (Ho) for on-line CPE-ICP-OES without 8-Ox as chelating agent, respectively. The sample throughput of 17 samples h-1 was obtained for both systems. The developed methods of on-line CPE-ICP-OES were validated by the analysis of certified reference material (GBW07605, tea leaves) and real biological samples of pig liver, Auricularia auricula and mushroom.
[en] Under high humidity and appropriate temperature, tris (8-hydroxyquinoline) aluminum (Alq3) solid micro/nanostructures may be etched into hollow structures and still retain their crystalline structures and surface morphologies. The shapes and sizes of the hollow structures are easily adjusted by varying the experimental parameters. Throughout the entire process, water is introduced into the system instead of organic or corrosive solvents, making this method convenient and environmentally friendly; it can also be extended to application in other materials such as TCNQ.
[en] Amorphous tris-(8-hydroxyquinoline)aluminum (Alq3) layers, which first form Alq3 islands and then grow into submicrometre thorns, with different nominal thicknesses are investigated. The field emission characteristics of Alq3 submicrometre thorns with nominal thicknesses of 20 nm, 50 nm and 100 nm include low turn-on fields of 3.2 V µm−1, 6.8 V µm−1 and 9.0 V µm−1 at 10 µA cm−2, and low threshold fields of 5.1 V µm−1, 10.0 V µm−1 and 13.0 V µm−1 at 1 mA cm−2, respectively. The enhanced field emission properties are governed by the morphology of Alq3 submicrometre thorns, which can be controlled by the evaporation rate and the layer thickness. A significant hysteresis in the cycle testing of the current density with a rise and fall electric field process, which is an undesirable property for practical applications, is observed in the case of the considered samples. This hysteresis can be eliminated via an increase in the nominal thicknesses and tests, and this is important for practical applications. The microstructure and adsorption/desorption effect are responsible for this hysteresis phenomenon. Amorphous Alq3 submicrometre thorns with good field emission properties are promising candidates for application as field emitters. (paper)
[en] A selective method of molybdenum determination has been developed which is based on adsorption preconcentration of molybdenum (6) complex with oxine at a stationary mercury microelectrode without its external polarization. With cathodic polarization of the electrode, a catalytic hydrogen wave due to a molybdenum (5) complex, formed during adsorbed complex electroreduction, is recorded. Down 2·10-3 μg Mo/ml can be determined from the catalytic current
[en] Extraction of uranium(VI) in presence of a mixture of oxine and β-diketones, viz. benzoyltrifluoroacetone, trifluoroacetylacetone, thenoyltrifluoroacetone and furoyltrifluoroacetone was studied. Extraction was found to be higher than that for oxine or β-diketone alone and the loss of uranium due to precipitation by oxine was eliminated completely. The synergistic species was found to be a mixed chelate and the nature of the species and equilibrium constant were evaluated. A correlation between the two phase stability constants and dissociation constants and partition coefficients of the β-diketones was also established. (author)
[en] We report the effect of oblique angle deposition of α-naphthylphenylbiphenyl diamine (α-NPD) on the performance of organic light-emitting diodes (OLEDs) based on tris-(8-hydroxyquinoline) aluminium (Alq3). OLEDs were fabricated by depositing α-NPD using both conventional and oblique angles of incidence α = 850 from the substrate normal. Due to oblique angle deposition tilted granular nano-structures of α-NPD were observed. It was found that the granular structure of α-NPD enhances the external coupling efficiency of the device. Significant enhancement in luminance was observed in the case of OLEDs fabricated using oblique angle deposition of α-NPD