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Mixed Aqueous Solution (mixed aqueous + solution)
Selected AbstractsMesoporous Hydrous Manganese Dioxide Nanowall Arrays with Large Lithium Ion Energy Storage CapacitiesADVANCED FUNCTIONAL MATERIALS, Issue 7 2009Dawei Liu Abstract Novel nanowall arrays of hydrous manganese dioxide MnO2,·,0.5H2O are deposited onto cathodic substrates by the potentiostatic method from a mixed aqueous solution of manganese acetate and sodium sulfate. The deposition is induced by a change of local pH resulting from electrolysis of H2O, and hierarchical mesoporous nanowall arrays are formed as a result of simultaneous precipitation of manganese hydroxide and release of hydrogen gas bubbles from the cathode. The morphology and lithium ion intercalation properties are found to change appreciably with the concentration of the precursor electrolyte, with a significant reduction in specific surface area with an increased precursor concentration. For example, mesoporous nanowall arrays deposited from 0.1,M solution possess a surface area of ,96,m2 g,1 and exhibit a stable high intercalation capacity of 256,mA hg,1 with a film of 0.5,µm in thickness, far exceeding the theoretical limit of 150,mA hg,1 for manganese dioxide bulk film. Such mesoporous nanowall arrays offer much greater energy storage capacity (e.g., ,230,mA hg,1 for films of ,2.5,µm) than that of anodic deposited films of the same thickness (,80,mA hg,1). Such high lithium ion intercalation capacity and excellent cyclic stability of the mesoporous nanowall arrays, especially for thicker films, are ascribed to the hierarchically structured macro- and mesoporosity of the MnO2,·,0.5H2O nanowall arrays, which offer large surface to volume ratio favoring interface Faradaic reactions, short solid-state diffusion paths, and freedom to permit volume change during lithium ion intercalation and de-intercalation. [source] Combustion synthesis and characterization of nano-crystalline LaFeO3 powderPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2009Hui Shen Abstract Nano-crystalline LaFeO3 was synthesized by a sol,gel auto-combustion method from a mixed aqueous solution of lanthanum and iron nitride, using citric acid as the fuel. Powder X-ray diffraction and TG/DTA analysis show that the LaFeO3 crystallites can be directly obtained by the sol,gel combustion process, without any other undesired phase. The results of SEM and TEM reveal that the as-burnt samples and powder calcined at 700 °C are agglomerated with particle size in the range of 25,50 nm and 60,80 nm, respecitvely. The M (T) and M (H) curves measurements show the existence of a weak ferromagnetism and the mainly anti-ferromagnetic ordering of the spins in the calcined sample. Compared with the powder calcined at 600 °C and 700 °C, the as-burnt LaFeO3 exhibits much stronger ferromagnetic behavior, with larger magnetization and smaller coercive field. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Structure and physico-chemical properties in mixed aqueous solution of sodium alkylcarboxylate-alkyltrimethylammonium bromideCHINESE JOURNAL OF CHEMISTRY, Issue 3 2000Huang Jian-Bin Abstract The physico-chemical properties of organized assemblies (micelle or vesicle) from sodium alkylcarboxylate - alkyltrimethyl -ammonium bromide mixture have been investigated systematically. In different mixed cationc-anionic surfactant systems, micelles and vesicles can coexist or be transformed into each other on different conditions. The experimental results are explained prelimilarily from the viewpoint of molecular packing geometry. The solubilization of organic compound in the mixed surfactant system was also studied in detail. [source] Predictive Equations for Dielectric Properties of NaCl, D-sorbitol and Sucrose Solutions and Surimi at 2450 MHzJOURNAL OF FOOD SCIENCE, Issue 6 2002P. Yaghmaee And ABSTRACT: Variation in dielectric properties of aqueous solutions with different concentrations and ratios of NaCl, D-sorbitol, and sucrose were investigated at 21 °C using the open-ended coaxial probe technique at 2450 MHz. Several equations to estimate dielectric properties of mixed or pure solutions were formulated. The equations were tested with other concentrations of solutions and surimi as a food sample containing the solutes. The correlation between the new measured dielectric properties and the calculated values were analyzed using a General Linear Model. The resultant prediction equations are suitable for pure and mixed aqueous solutions of (0 to 6%) NaCl, (0 to 18%) D-sorbitol and (0 to 60%) sucrose. For surimi, only loss factor was successfully predicted. [source] Structural compatibility of novel nucleotide modifications with shortened linkages designed for antigene/antisense therapyJOURNAL OF RAMAN SPECTROSCOPY, Issue 5 2004J. Hanu Abstract The impact of isopolar shortened internucleotide linkage modification on the hybridization properties of potential antisense or antigene oligonucleotides was studied by using a model molecular system consisting of polyuridylic acid (PolyU) and analogs of diadenosine monophosphate with the modified linkage. Raman spectra of mixed aqueous solutions were measured at various temperatures and compositions of the mixtures for four types of modified linkage and natural ApA (3,,5,) as a reference. Analysis of the spectral sets provided amounts of formed complexes and their Raman spectra. It has been found that as in the case of ApA (3,,5,), the studied ApA analogs form with PolyU triplex-like complexes containing a central pseudo-chain of closely arranged adenosine dimers. In the case of S - and R -configured 2,,5, and 3,,5, ApCOH A analogs, respectively, the amounts of complexes formed even exceed the ApA. This hybridization effectiveness is reached, however, by a more feasible prolongation of the pseudo-chain, while the stability constant for the initiation step is significantly lower. Raman spectra of the complexes showed that for both of the above analogs the structural compatibility with the natural nucleic acid chain is decreased, because of the distorted position of one adenine residue. This distortion influences the Watson,Crick hydrogen bonds. The two types of linkages may be suitable just for construction of longer antigene or antisense oligonucleotides with alternating lengthened and shortened linkages. There is, however, a warning of possible decreased binding specificity. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||