Nanometer-Sized Bi Particles in Aqueous Solution:  Absorption Spectrum and Some Chemical Properties

1996 ◽  
Vol 100 (18) ◽  
pp. 7656-7661 ◽  
Author(s):  
Maritza Gutiérrez ◽  
Arnim Henglein
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectrum ◽  
Chemical Properties

scholarly journals Self-association of unconjugated bilirubin-IX α in aqueous solution at pH 10.0 and physical-chemical interactions with bile salt monomers and micelles

1979 ◽  
Vol 179 (3) ◽  
pp. 675-689 ◽  
Author(s):  
M C Carey ◽  
A P Koretsky
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectrum ◽  
Bile Salt ◽  
Bile Salts ◽  
Sodium Dodecyl ◽  
Chemical Properties ◽  
Critical Micellar Concentration ◽  
Solvent Mixtures ◽  
Physical Chemical ◽  
Self Association

Spectrophotometric measurements of bilirubin-IX alpha in water and in aqueous/organic solvent mixtures at pH 10.0 as a function of bilirubin-IX alpha concentration (approx. 0.6–400 microM) are consistent with the formation of dimers (KD - 1.5 microM) in dilute (less than 10 microM) aqueous solution and further self-aggregation to multimers at higher concentrations. Added urea (to 10M) and increases in temperature (to 62 degrees C) obliterate the dimer-multimer transition at 10 microM, but added NaCl (to 0.30 M) promotes strong aggregation of dimers over a narrow concentration range, suggesting a ‘micellization’ phenomenon. Concentrations of dioxan or ethanol greater than 60% (v/v) in water were required to obtain the absorption spectrum of bilirubin-IX alpha monomers, suggesting that both hydrophobic and electrostatic (pi-orbital) interactions are involved in stabilizing the dimeric state in water. Micellar concentrations of sodium dodecyl sulphate induced spectrophotometric shifts in the dimer absorption spectrum of bilirubin-IX alpha consistent with progressive partitioning of bilirubin-IX alpha monomers into a relatively non-polar region of the micelles and allowed a deduction of the apparent critical micellar concentration that closely approximated the literature values. The pattern of bilirubin IX alpha association with bile salts is complex, since the absorption spectrum shifts hypsochromically below and bathochromically above the critical micellar concentration of the bile salts. Consistent with these observations, bilirubin IX alpha appears to bind to the polar face of bile salt monomers and to the polar perimeter of small bile salt micelles. At higher bile salt concentrations some-bilirubin-IX alpha monomers partition into the hydrophobic interior of the bile salt micelles. Our results suggest that under physiological conditions the natural conjugates of bilirubin-IX alpha may exhibit similar physical chemical properties in bile, in that dimers, highly aggregated multimers and bile salt-associated monomers may co-exist.

scholarly journals Chemical Properties of Element 105 in Aqueous Solution: Halide Complex Formation and Anion Exchange into Triisoctyl Amine

1989 ◽  
Vol 48 (3-4) ◽  
Author(s):  
J. V. Kratz ◽  
H. P. Zimmermann ◽  
U. W. Scherer ◽  
M. Schädel ◽  
W. Brüchle ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Anion Exchange ◽  
Chemical Properties ◽  
Halide Complex

scholarly journals Chemical Properties of Element 105 in Aqueous Solution: Back Extraction from Triisooctyl Amine into 0.5 M HCl

1993 ◽  
Vol 60 (1) ◽  
Author(s):  
H. P. Zimmermann ◽  
M. Κ. Gober ◽  
J. V. Kratz ◽  
M. Schädel ◽  
W. Brüchle ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Chemical Properties ◽  
Back Extraction

The impact of β-cyclodextrin on biological and chemical properties of mianserin hydrochloride in aqueous solution

2020 ◽  
Vol 314 ◽  
pp. 113589 ◽  
Author(s):  
S. Belica-Pacha ◽  
K. Miłowska ◽  
M. Ionov ◽  
M. Bryszewska ◽  
A. Buczkowski ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Chemical Properties ◽  
The Impact ◽  
And Chemical Properties

Absorption Spectrum and Chemical Reactions of Colloidal Cadmium in Aqueous Solution

1992 ◽  
Vol 272 ◽  
Author(s):  
M. Gutiérrez ◽  
A. Henglein
Keyword(s):  
Aqueous Solution ◽  
Nitrous Oxide ◽  
Absorption Spectrum ◽  
Carbon Tetrachloride ◽  
Chemical Reactions ◽  
Redox Reactions ◽  
Methyl Viologen ◽  
Narrow Band ◽  
Optical Data

ABSTRACTA radiolysis method is described to prepare isolated cadmium particles in aqueous solution. The spectrum of these particles (narrow band at 260nm) agrees with the spectrum calculated from the optical data of cadmium. Clusters of particles absorb at longer wavelengths. Redox reactions of the particles with methyl viologen, nitrous oxide and carbon tetrachloride were also investigated. It is shown that the absorption spectrum of the particles changes during these reactions as de-clustering takes place.

Atomic absorption background of Ba in EXAFS analysis of BaFe12O19nanoparticles

2011 ◽  
Vol 18 (4) ◽  
pp. 557-563 ◽  
Author(s):  
Jana Padežnik Gomilšek ◽  
Alojz Kodre ◽  
Iztok Arčon ◽  
Simone de Panfilis ◽  
Darko Makovec
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectrum ◽  
Atomic Absorption ◽  
Energy Region ◽  
Structural Parameters ◽  
Simple Analytical Model ◽  
Absorption Signal ◽  
X Ray ◽  
Exafs Analysis ◽  
Atomic Absorption Spectra

The approximate barium X-ray atomic absorption in the energy region ofL-edges is reconstructed from the absorption spectrum of an aqueous solution of BaCl2. The result is corroborated by comparison with pure atomic absorption spectra of neighbour elements Xe and Cs. The application of the atomic absorption signal as a proper EXAFS background is demonstrated and discussed in the analysis of Ba hexaferrite nanoparticles with a very weak structural signal. The essential gain is found in the decrease of uncertainty intervals of structural parameters and their correlations. A simple analytical model of the absorption background for the practical EXAFS analysis is demonstrated.

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