Search results for "ionic"
showing 10 items of 2016 documents
Monolayer black phosphorus by sequential wetchemical surface oxidation
2018
We report a straightforward chemical methodology for controlling the thickness of black phosphorus flakes down to the monolayer limit by layer-by-layer oxidation and thinning, using water as solubilizing agent.
Polymeric nanospheres as strategy to increase the amount of triclosan retained in the skin: passive diffusion vs. iontophoresis
2012
The aim of this study was to evaluate the passive and iontophoretic permeation of triclosan in human skin using a triclosan solution and triclosan-loaded cationic nanospheres in order to determine which of the two strategies is more effective in allowing the deposition of triclosan within the skin. Triclosan-loaded nanospheres were prepared by the emulsification-solvent displacement technique using aminoalkyl methacrylate (Eudragit® RL 100) as polymer matrix. Nanospheres of 261.0 ± 15.1 nm with a positive surface charge (Ψz = 26.0 ± 3.2 mV) were obtained. Drug loading was 62.0 ± 1.7%. Results demonstrated that the amount of triclosan retained within the skin was significantly greater (8.5-f…
Stability of the fergusonite phase in GdNbO 4 by high pressure XRD and Raman experiments
2017
Abstract We describe the results of high pressure x-ray diffraction and Raman measurements on gadolinium orthoniobate. The ambient pressure monoclinic fergusonite phase remains stable in a remarkable large pressure range. There is no significative evolution of the monoclinic distortion up to 25 GPa , the maximum pressure achieved. Instead, the anisotropic compressibility is associated to the stiffness of NbO 4 tetrahedra in respect to the GdO 8 polyhedra. The high pressure evolution of external modes parallels the wavenumber dependence on ionic radius along the lanthanide series. The chemical pressure analogy is attributed to the compression of GdO 8 polyhedra. There is no evidence of any p…
Non-linear optical study of hierarchical 3D Al doped ZnO nanosheet arrays deposited by successive ionic adsorption and reaction method
2020
Abstract Successive ionic layer adsorption and reaction (SILAR) method is based on the adsorption and reaction of the ions in the cationic solution and the ionic solution, respectively. This method is simple, inexpensive, large-scale deposition, effective way for deposition on 3D substrates, low-temperature process and represents an easy way for the preparation of doped, composite and heterojunction materials. To take advantage of this method and the ZnO nanostructures, various parameters have been optimized. Undoped and Aluminum (Al) doped ZnO nanostructures were prepared by the SILAR technique. The characterization of the nanostructures prepared was carried out using X-ray diffraction (XR…
Temperature dependent optical properties of stacked InGaAs/GaAs quantum rings
2008
4 páginas, 3 figuras, 2 tablas.-- MADICA 2006 Conference, Fifth Maghreb-Europe Meeting on Materials and their Applicatons for Devices and Physical, Chemical and Biological Sensors
Temperature Effect of Ionic Transition Metal Complex Light-Emitting Electrochemical Cells
2013
ABSTRACTLight-Emitting Electrochemical Cells (LECs) consist of solution processable ionic light-emitting materials and use air stable electrodes. Their operational mechanism relies on both ionic and electronic conduction. The dynamic behavior is primarily determined by the ionic conductivity. Here, we demonstrate that with increasing temperature the LECs turn-on faster yet without decreasing the efficiency. This is due to the activation energy of ionic transport and the temperature independent photoluminescence quantum yields.
Exploring the effect of the cyclometallating ligand in 2-(pyridine-2-yl)benzo[d]thiazole-containing iridium(III) complexes for stable light-emitting …
2018
The preparation and characterization of a series of iridium(III) ionic transition-metal complexes for application in light-emitting electrochemical cells (LECs) are reported. The complexes are of the type [Ir(C^N)2(N^N)][PF6] in which C^N is one of the cyclometallating ligands 2-(3-(tert-butyl)phenyl)pyridine (tppy), 2-phenylbenzo[d]thiazole (pbtz), 1-phenyl-1H-pyrazole (ppz) and 1-phenylisoquninoline (piq), and N^N is 2-(pyridine-2-yl)benzo[d]thiazole (btzpy). The variation in the C^N ligands allows the HOMO energy level to be tuned, leading to HOMO–LUMO gaps in the range 2.76–3.01 eV and values of Eox1/2 of 0.81–1.11 V. In solution, the complexes are orange to deep-red emitters (λmax in t…
Synthesis, structure and spectroscopic properties of luminescent GdVO 4 :Dy 3+ and DyVO 4 particles
2018
Part of this research was done during visit of D.J. to IFN-CNR CSMFO Lab. and FBK Photonics Unit, Povo-Trento, Italy, in the framework of the STSM (Grant No. 38223) from the project: COST Action MP 1401 Advanced Fibre Laser and Coherent Source as tools for Society, Manufacturing and Lifescience” (2014e2018). The authors from Vinca Institute of Nuclear Sciences acknowledge the financial support of the Ministry of Education, Science and Tech-nological Development of the Republic of Serbia (Project No: 45020 and 172056). L.T.N. Tran acknowledges the scholarship of the Ministry of Education and Training, Vietnam International Education Development. T. G. acknowledges the ERDF PostDoc project No…
Angstrom-Size Defect Creation and Ionic Transport through Pores in Single-Layer MoS2
2018
Atomic-defect engineering in thin membranes provides opportunities for ionic and molecular filtration and analysis. While molecular-dynamics (MD) calculations have been used to model conductance through atomic vacancies, corresponding experiments are lacking. We create sub-nanometer vacancies in suspended single-layer molybdenum disulfide (MoS2) via Ga+ ion irradiation, producing membranes containing ∼300 to 1200 pores with average and maximum diameters of ∼0.5 and ∼1 nm, respectively. Vacancies exhibit missing Mo and S atoms, as shown by aberration-corrected scanning transmission electron microscopy (AC-STEM). The longitudinal acoustic band and defect-related photoluminescence were observe…
Surface modification of all-inorganic lead halide perovskite nanocrystals
2021
Abstract Newly emerged all-inorganic lead halide perovskite nanocrystals have shown unprecedented optical properties for a variety of display applications. Their superior optical properties over traditional semiconductor nanocrystals have opened a new paradigm in luminescent materials research. Because of their defect tolerance, the photoluminescent quantum yield of lead halide perovskite nanocrystals can reach near-unity. However, the ionic character of these nanocrystals causes extreme lability, which deteriorates its structural and optical properties. Moreover, the binding ability of surface ligands are quite weak and thus easily desorb during conventional purification techniques. Despit…