143-19-1Relevant articles and documents
Shape Transition of TiO2 Nanocube to Nanospindle Embedded on Reduced Graphene Oxide with Enhanced Photocatalytic Activity
Mukhopadhyay, Soumita,Maiti, Debabrata,Saha, Arindam,Devi, Parukuttyamma Sujatha
, p. 6922 - 6932 (2016)
In this study, we report a facile synthetic route for the transition of anatase TiO2 nanocube to nanospindle with coexposed {001} and {101} facets on a reduced graphene oxide (rGO) platform. Initially, a TiO2 nanocubes/graphene oxide suspension in an ethanol-water solvent mixture was hydrothermally treated at 180 °C for various reaction durations to perform the in situ growth of TiO2 and simultaneous reduction of graphene oxide to rGO. All composites resulted in the formation of anatase TiO2 with a surface heterojunction formed by coexposed {101} and {001} facets embedded on an rGO sheet. Interestingly, it was observed that 4 h of hydrothermal treatment resulted in the formation of a TiO2 nanospindle with enhanced {001} high energy facet % embedded on an rGO sheet. The photocatalytic performance of the products was evaluated for the photodegradation of malachite green under simulated solar irradiation. All TiO2@ rGO composites exerted enhanced activity as compared to the native TiO2 cube owing to enhanced adsorption and fast electron migration by the rGO platform. Furthermore, the TiO2 spindle @rGO exhibited the highest photocatalytic activity with a 6 fold increase in efficiency over the native TiO2 cube. This superior performance of the nanospindle was ascribed to the synergistic effect of enhanced {001} facet percentage in the surface heterojunction and close interfacial contact with the rGO platform.
Adsorption of Anions of Higher Carboxylic Acids on Magnesium from Weakly Alkaline Aqueous Solutions
Andreeva, N. P.,Chirkunov, A. A.,Kuznetsov, Yu. I.,Luchkin, A. Yu.,Ogorodnikova, V. A.
, p. 1104 - 1110 (2020)
Abstract: The adsorption of sodium salts of higher carboxylates on oxidized magnesium is studied via in situ reflective ellipsometry. It is shown that the free energies of adsorption of sodium oleyl sarcosinate (OsS) and sodium linoleate (LiS) is >55 kJ/mol, indicating the chemisorption of carboxylates on oxidized magnesium surfaces. Electrochemical impedance spectra, voltammetry, and corrosion testing show that sodium oleate (OlS) has the best protective properties on pure and oxidized magnesium. The strong protective properties of OlS are confirmed by Mg plate testing under conditions of a wet atmosphere with daily condensation. Tentative passivation of chemically oxidized Mg in a 16 mmol/L OlS solution protects against corrosion for 92–96 h.
Rapid Synthesis of Sub-10 nm Hexagonal NaYF4-Based Upconverting Nanoparticles using Therminol 66
Hesse, Julia,Klier, Dennis T.,Sgarzi, Massimo,Nsubuga, Anne,Bauer, Christoph,Grenzer, J?rg,Hübner, René,Wislicenus, Marcus,Joshi, Tanmaya,Kumke, Michael U.,Stephan, Holger
, p. 159 - 168 (2018)
We report a simple one-pot method for the rapid preparation of sub-10 nm pure hexagonal (β-phase) NaYF4-based upconverting nanoparticles (UCNPs). Using Therminol 66 as a co-solvent, monodisperse UCNPs could be obtained in unusually short reaction times. By varying the reaction time and reaction temperature, it was possible to control precisely the particle size and crystalline phase of the UCNPs. The upconversion (UC) luminescence properties of the nanocrystals were tuned by varying the concentrations of the dopants (Nd3+ and Yb3+ sensitizer ions and Er3+ activator ions). The size and phase-purity of the as-synthesized core and core–shell nanocrystals were assessed by using complementary transmission electron microscopy, dynamic light scattering, X-ray diffraction, and small-angle X-ray scattering studies. In-depth photophysical evaluation of the UCNPs was pursued by using steady-state and time-resolved luminescence spectroscopy. An enhancement in the UC intensity was observed if the nanocrystals, doped with optimized concentrations of lanthanide sensitizer/activator ions, were further coated with an inert/active shell. This was attributed to the suppression of surface-related luminescence quenching effects.
Potassium Bromide Surface Passivation on CsPbI3-xBrx Nanocrystals for Efficient and Stable Pure Red Perovskite Light-Emitting Diodes
Yang, Jun-Nan,Song, Yang,Yao, Ji-Song,Wang, Kun-Hua,Wang, Jing-Jing,Zhu, Bai-Sheng,Yao, Ming-Ming,Rahman, Sami Ur,Lan, Yi-Feng,Fan, Feng-Jia,Yao, Hong-Bin
, p. 2956 - 2967 (2020/02/04)
All-inorganic lead halide perovskite nanocrystals (NCs) are potential candidates for fabricating high-performance light-emitting diodes (LEDs) owing to their precisely tunable bandgaps, high photoluminescence (PL) efficiency, and excellent color purities. However, the performance of pure red (630-640 nm) all-inorganic perovskite LEDs is still limited by the halide segregation-induced instability of the electroluminescence (EL) of mixed halide CsPbI3-xBrx NCs. Herein, we report an effective approach to improving the EL stability of pure red all-inorganic CsPbI3-xBrx NC-based LEDs via the passivation of potassium bromide on NCs. By adding potassium oleate to the reaction system, we obtained potassium bromide surface-passivated (KBr-passivated) CsPbI3-xBrx NCs with pure red PL emission and a photoluminescence quantum yield (PLQY) exceeding 90%. We determine that most potassium ions present on the surface of NCs bind with bromide ions and thus demonstrate that potassium bromide surface passivation of NCs can both improve the PL stability and inhibit the halide segregation of NCs. Using KBr-passivated CsPbI3-xBrx NCs as an emitting layer, we fabricated stable and pure red perovskite LEDs with emission at 637 nm, showing a maximum brightness of 2671 cd m-2, maximum external quantum efficiency of 3.55%, and good EL stability. The proposed KBr-passivated NC strategy will open a new avenue for fabricating efficient, stable, and tunable pure color perovskite NC LEDs.
Fatty acid ionic liquids as environmentally friendly lubricants for low friction and wear
Gusain, Rashi,Khatri, Om P.
, p. 3462 - 3469 (2016/01/20)
Vegetable oils are environmentally-friendly, sustainable and rich source of fatty acids, and have been used as lubricants since ancient times. The carboxylic group of fatty acids interacts with metal surface and forms the tribo-chemical thin film of low shear strength under the boundary lubrication, which reduces the friction and the wear. Herein, four fatty acids having variable chain length and unsaturated sites are selected as anionic precursors to prepare the tetrabutylammonium-fatty acid ionic liquids. The preparation of these ionic liquids is confirmed by FTIR and NMR (1H and 13C) analyses. The chain length and degree of unsaturation in the fatty acid anions control the viscosity, melting temperature, crystallization temperature and latent heat of fatty acid ionic liquids. These ionic liquids as lubricants exhibited significantly lower friction (18-50%) compared to polyol ester lube base oil. Further, the degree of friction reduction is largely influenced by the structure of the constituent fatty acid anion. The oleate anion showed the best tribo-performance among all fatty acid ionic liquids being studied. The elemental mapping of worn surfaces revealed the formation of fatty acid ionic liquids constituted a tribo-chemical thin film. Being halogen-free and abundantly available sources of fatty acid precursors, these ionic liquids promise immense potential for tribological applications, where the friction and environment are of prime importance.
ANTIVIRAL AGENT AND CLEANSING AGENT
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, (2012/03/10)
It is an object to provide an antiviral agent that can be used for persons having sensitive skin or on the face, inactivates viruses such as a norovirus and an influenza virus, and is excellent in germicidal properties. Further provided is a cleansing agent that does not lead to environmental pollution since the cleansing agent is easily decomposed in the natural environment, scarcely causes eczema and allergic dermatitis since no germicidal agent is added, and has an antiviral performance. The antiviral agent containing a surface-active agent having a C18 unsaturated alkyl group as an active component. It is not always necessary to lather or rinse off with water like cleansing agents such as medicated soaps since the antiviral agent of the present invention at a very low concentration can inactivate the virus.
CLEAR PHARMACEUTICAL AQUEOUS MICROEMULSION COMPRISING PROPOFUOL AND PROCESS FOR PREPARATION
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Page/Page column 8, (2008/06/13)
The present invention concerns a clear pharmaceutical aqueous emulsion composition which comprises Propofol and a surfactant system and which is particularly usable for a safe administration through intravenous injection. A composition according to the invention is characterized in that said surfactant system comprises in combination at least one pharmaceutically acceptable monovalent metal salt of a fatty acid having from 5 to 23 carbon atoms, and at least one polyethylene glycol hydroxystearate. This combination allows to use a mass ratio (w/w) surfactant system / Propofol which is less than 4 and preferably less than or equal to 2.8, while obtaining such a clear composition.
Aminosulfonylcarboxylic acids and their salts
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, (2008/06/13)
Aminosulfonylcarboxylic acids and their manufacture from diamines and chlorosulfonylcarboxylic acids.
