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671.
Thermally evaporated Ag nanoparticle films for plasmonic enhancement in organic solar cells: effects of particle geometry
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Gholamhosain Haidari Morteza Hajimahmoodzadeh Hamid Reza Fallah Andreas Peukert Alina Chanaewa Elizabeth von Hauff 《固体物理学:研究快报》2015,9(3):161-165
We report on the simple fabrication of Ag NP films via thermal evaporation and subsequent annealing. The NPs are formed on indium tin oxide electrodes, coated with PEDOT:PSS and implemented into PCPDTBT:PC70BM solar cells. Scanning electron microscopy and atomic force microscopy are used to determine the size distributions and surface coverage of the NP film. We apply finite‐difference time‐domain techniques to model the optical properties of different nanoparticle films and compare this with the absorption properties of the organic active layer. The simulations demonstrate that the absorption and scattering efficiency of the particles are very sensitive to particle geometry. Solar cells prepared with window electrodes containing NP layers with less surface coverage, show a 14.8% improvement in efficiency. We discuss variations in the external quantum efficiency of the devices in terms of forward scattering and parasitic absorption losses induced by the NP layer. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
672.
Lyudmyla V. Karabanova Raymond L. D. Whitby Vladimir A. Bershtein Alina V. Korobeinyk Pavel N. Yakushev Oksana M. Bondaruk Andrew W. Lloyd Sergey V. Mikhalovsky 《Colloid and polymer science》2013,291(3):573-583
Acid-oxidized multiwalled carbon nanotubes (MWCNTs) were introduced into a polyurethane (PU) matrix at low filler levels (0.01–0.25 wt%) through either van der Waals or covalent interactions, and their glass transition dynamics using dynamic mechanical analysis and laser-interferometric creep rate spectroscopy was investigated. The nanocomposites reveal substantial impact on the PU glass transition dynamics, which depends on the nanotube content and type of interfacial interactions. The pronounced dynamic heterogeneity within the glass transition covering 200 °C range and the displacement of main PU relaxation maxima from around 0 to 80–140 °C were registered. The results are treated in the framework of chemical inhomogeneity, constrained dynamics effects, and different motional cooperativities. The peculiariaties of the glass transition dynamics in the composites are reflected in their dynamic and static mechanical properties, in particular a two- to threefold increase in modulus and tensile strength for the covalent interfacial interaction of MWCNTs with PU. 相似文献
673.
Piotr Guga Krzysztof Domański Maria Koziołkiewicz Alina Owczarek Wojciech J. Stec 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6-7):1601-1604
Diastereomerically pure, isotopically labeled 5'- O -DMT-nucleoside-3'- O -(2-thio-4,4-"spiro"-pentamethylene-1,3,2-[ 18 O]oxathiaphospholane)s and -(2-oxo-4,4-"spiro"-pentamethylene-1,3,2-[ 18 O]oxathiaphospholane)s suitable for stereocontrolled synthesis of P-chiral oligonucleotide [ 18 O]phosphorothioates and [ 18 O]phosphates were synthesized. Obtained in that way "chimeric" oligonucleotide d[A PO A PS-Rp,Sp A PS-Rp , Sp A PS-Rp C PS(18O)-Rp G PS-Rp T PS-Rp T PS-Rp,Sp T PO T] was used for determination of the stereochemistry of hydrolysis by endonuclease from Serratia marcescens . 相似文献
674.
A new liquid chromatographic (LC) method for simultaneous determination of lidocaine hydrochloride (LH) and tribenoside (TR) along with their related compounds in pharmaceutical preparations is described. Satisfactory LC separation of all analytes after the liquid–liquid extraction (LLE) procedure with ethanol was performed on a C18 column using a gradient elution of a mixture of acetonitrile and 0.1 % orthophosphoric acid as the mobile phase. The procedure was validated according to the ICH guidelines. The limits of detection (LOD) and quantification (LOQ) were 4.36 and 13.21 μg mL?1 for LH, 7.60 and 23.04 μg mL?1 for TR, and below 0.11 and 0.33 μg mL?1 for their impurities, respectively. Intra- and inter-day precision was below 1.97 %, whereas accuracy for all analytes ranged from 98.17 to 101.94 %. The proposed method was sensitive, robust, and specific allowing reliable simultaneous quantification of all mentioned compounds. Moreover, a comparative study of the RP-LC column classification based on the quantitative structure-retention relationships (QSRR) and column selectivity obtained in real pharmaceutical analysis was innovatively applied using factor analysis (FA). In the column performance test, the analysis of LH and TR in the presence of their impurities was carried out according to the developed method with the use of 12 RP-LC stationary phases previously tested under the QSRR conditions. The obtained results confirmed that the classes of the stationary phases selected in accordance with the QSRR models provided comparable separation for LH, TR, and their impurities. Hence, it was concluded that the proposed QSRR approach could be considered a supportive tool in the selection of the suitable column for the pharmaceutical analysis. 相似文献
675.
Self-assembly processes are considered to be fundamental factors in supramolecular chemistry. Langmuir monolayers of surfactants or lipids have been shown to constitute effective 2D "templates" for self-assembled nanoparticles and colloids. Here we show that alkyl-coated gold nanoparticles (Au NPs) adopt distinct configurations when incorporated within Langmuir monolayers comprising two lipid components at different mole ratios. Thermodynamic and microscopy analyses reveal that the organization of the Au NP aggregates is governed by both lipid components. In particular, we show that the configurations of the NP assemblies were significantly affected by the extent of molecular interactions between the two lipid components within the monolayer and the monolayer phases formed by each individual lipid. This study demonstrates that multicomponent Langmuir monolayers significantly modulate the self-assembly properties of embedded Au NPs and that parameters such as the monolayer composition, surface pressure, and temperature significantly affect the 2D nanoparticle organization. 相似文献
676.
Alina Tirsoaga Diana Visinescu Bogdan Jurca Adelina Ianculescu Oana Carp 《Journal of nanoparticle research》2011,13(12):6397-6408
Nanosized metal aluminates, MAl2O4 (M = Ni, Co), have been prepared following a nonpolluting, low temperature, and self-sustaining starch single-fuel combustion
synthesis. The mixed fuel-coordinating actions of starch have given rise to an intermediary precursor which afforded monodisperse
metal aluminate nanoparticles. The thermal analysis of the [M(II), Al(III)]-starch precursors indicates a similar thermochemical
reactivity for the two compounds, displaying a sequence of well-defined decomposition stages associated with three endothermic
effects and three/four (nickel/cobalt) exothermic ones. The XRD data confirm the formation of spinelic phase and a continuous
growth of particle sizes with the increase of calcination temperatures. The mechanisms proposed for the formation of metal
aluminates essentially consist in a combination of solid-state reactions of amorphous NiO/Co3O4 and Al2O3 simple oxides. The evaluation criterion of Ni(II) cations into the spinelic lattice is original and is based on the distinct
occupancy degree of tetrahedral and octahedral sites in NiAl2O4 and γ-Al2O3. TEM/HRTEM investigations performed on the cobalt(II) and nickel(II) aluminate oxide powders resulted after calcination at
800 and 900 °C, respectively, for 1 h show the formation of irregular and isolated plate-like particles for Co(II)-based spinelic
oxides (the average particle size is 16.6 nm) and submicron aggregates of small, bimodal, and almost uniform (as shape and
size) of NiAl2O4 mixed oxide (the mean particle size is 33.6 nm). The NIR–UV–Vis spectra for the resulted MAl2O4 (M = Co, Ni) mixed oxides reveal a massive presence of tetrahedral divalent cations both for short- and long-time calcined
samples. NiO impurities are detected using FTIR and electronic spectra for all NiAl2O4 samples. 相似文献
677.
Raymond L. D. Whitby Alina Korobeinyk Sergey V. Mikhalovsky Takahiro Fukuda Toru Maekawa 《Journal of nanoparticle research》2011,13(10):4829-4837
Single-layer graphene oxide (SLGO) possesses carboxylic and hydroxyl groups suitable for reactions with aliphatic or aromatic
diisocyanate molecules. TEM analysis reveals that aliphatic diisocyanate molecules caused SLGO to scroll into star-like formations,
whereas aromatic diisocyanate molecules retained SGLO in a flat-sheet morphology. TGA confirms the stabilisation of the formed
urea and urethane groups on SLGO, but the onset of sheet pyrolysis occurs at a lower temperature due to isocyanate reactions
with anhydride and epoxide groups embedded in the sheet. Pendant isocyanate groups act as bridging units to facilitate the
attachment of pyrrole molecules, which are then used as anchor sites for the covalent polymerisation of pyrrole to polypyrrole
(PPy). The use of FeCl3 as the polymerisation catalyst generated both covalent and free PPy, but also iron hydroxide nanoparticles were observed
decorating the SLGO surface. When using ammonium persulfate as a catalyst and dodecylbenzenesulfonate as a dopant, free PPy
could be removed under treatment with solvents to leave a purely covalent system. Discrete regions of SLGO were observed decorated
with nanoparticles of PPy along the edge or across the surface of individual sheets. It was found that the flexibility of
the SLGO sheet and the type of diisocyanate used directly affected the electrical resistance of the final composite. 相似文献
678.
The fast neutron therapy facility at the University of Washington has been in routine clinical use for 25 years. 50.5 MeV protons produce neutrons in a beryllium target mounted on an isocentric gantry. Beam shaping is accomplished with a 40-leaf collimator. Dosimetry measurements for treatment planning and calibration are performed with tissue equivalent ion chambers. A layered phantom of alternating Solid Water® and Plastic Water® slabs has been developed for rapid dose verification measurements. The neutron field in the room has been used for radiation testing of electronic components. 相似文献
679.
Mihaela Homocianu Alina M. Ipate Corneliu Hamciuc Anton Airinei 《Journal of fluorescence》2018,28(5):1217-1224
The photophysical properties of the three 1,3,4-oxadiazole derivatives containing fluorene (Ox-FL); fluorene and phenolphtaleine (Ox-FL-FF); or fluorene and bisphenol A (Ox-FL-BPA) moieties in the main chain were investigated by the fluorescence and absorption spectroscopy in different solvents and in the solid state. The electronic absorption spectra included a strong absorption band located in the 270–395 nm region, with a maxima around at 302 nm. The fluorescence excitation spectra were also characterized by one broad band, appearing in the wavelength range of 220–340 nm. All samples displayed the emission bands around 356–373 nm and exhibit high quantum yields ranged from 31.61 to 90.77%, in chloroform solution. The sensitivity of the emission spectra on medium characteristics (polarity, acidity and basicity) were evaluated by using the Catalan solvent scale and the fluorescence titration with a dilute acid solution. 相似文献
680.
Alina Climova Ekaterina Pivovarova Bartomiej Rogalewicz Anita Raducka Magorzata Szczesio Izabela Korona-Gowniak Agnieszka Korga-Plewko Magdalena Iwan Katarzyna Gobis Agnieszka Czylkowska 《Molecules (Basel, Switzerland)》2022,27(11)
New coordination compounds of Mn(II), Fe(III), Co(II), and Ni(II) and the biologically active ligand L (N′-benzylidenepyrazine-2-carbohydrazonamide) were synthesized and characterized by appropriate analytical techniques: elemental analysis (EA), thermogravimetric analysis (TG–DTG), infrared spectroscopy (FTIR), and flame-atomic absorption spectrometry (F-AAS). The biological activity of the obtained compounds was then comprehensively investigated. Rational use of these compounds as potential drugs was proven by ADME analysis. All obtained compounds were screened in vitro for antibacterial, antifungal, and anticancer activities. Some of the studied complexes exhibited significantly higher activity than the ligand alone. 相似文献