scholarly journals Избирательная сольватация красителя 4-DASPI в бинарном растворителе вода-этиленгликоль

2021 ◽  
Vol 129 (12) ◽  
pp. 1502
Author(s):  
А.С. Степко ◽  
А.А. Медведева ◽  
А.В. Кошкин -=SUP=-1-=/SUP=- ◽  
П.В. Лебедев-Степанов
Keyword(s):  
Experimental Data ◽  
Dielectric Constant ◽  
Preferential Solvation ◽  
Solvation Shell ◽  
Theoretical Interpretation ◽  
Effective Dielectric Constant ◽  
Binary Solvent ◽  
Solvatochromic Shift ◽  
Solvent Water ◽  
Solvatochromic Shifts

Solvatochromic shifts of the absorption spectra maxima of the dye 4-DASPI (4- [4- (dimethylamino) styryl] -1-methylpyridinium iodide) in a binary solvent water-ethyleneglycol in the concentration range 0-100% were experimentally investigated. The dependence of the solvatochromic shift on the macroscopic dielectric constant of the solution and the concentration of ethyleneglycol was determined. The Onsager-Liptay model was used for the theoretical interpretation of the experimental data. It made it possible to estimate the effective dielectric constant in the microscopic area that contacts with dye chromophore taking into account the measured solvatochromic shifts. It was found that the value of the dielectric constant in the solvation shell of this dye differs significantly from the macroscopic value. The solvation shell is significantly enriched by ethyleneglycol (preferential solvation) over the components’ concentration range. The enrichment reaches its maximum approximately in the middle of this range. The composition of the dye solvation shell at different concentration is discussed.

Contributions to Silicon-Hydrogen Bond-Stretching Frequency in Amorphous Si Alloys

1992 ◽  
Vol 258 ◽  
Author(s):  
Z. Jing ◽  
J. L. Whitten ◽  
G. Lucovsky
Keyword(s):  
Experimental Data ◽  
Hydrogen Bond ◽  
Dielectric Constant ◽  
Ab Initio ◽  
Effective Dielectric Constant ◽  
Bond Energies ◽  
Calculated Frequency ◽  
Bond Stretching ◽  
Amorphous Si ◽  
Good Agreement

ABSTRACTWe have performed ab initio calculations and determined the bond-energies and vibrational frequencies of Si-H groups that are: i) attached to Si-atoms as their immediate, and also more distant neighbors; and ii) attached to three O-atoms as their immediate neighbors, but are connected to an all Si-atom matrix. These arrangements simulate bonding geometries on Si surfaces, and the calculated frequency for i) is in good agreement with that of an Si-H group on an Si surface. To compare these results with a-Si:H alloys it is necessary to take into account an additional factor: the effective dielectric constant of the host. We show how to do this, demonstrating the way results of the ab initio calculations should then be compared with experimental data.

Kinetic order with respect to solvent: Acid hydrolysis and preferential solvation of the Reineckate ion

1967 ◽  
Vol 45 (24) ◽  
pp. 3049-3053 ◽  
Author(s):  
Cooper H. Langford ◽  
John F. White
Keyword(s):  
Acid Hydrolysis ◽  
Preferential Solvation ◽  
Solvation Shell ◽  
Resonance Technique ◽  
Kinetic Order ◽  
Solvent Water ◽  
Acetone Water ◽  
Magnetic Resonance Technique ◽  
Hydrolysis Of

The nuclear magnetic resonance technique of preferential solvation analysis developed by Frankel, Stengle, and Langford is applied to determination of the composition of the solvation shell about trans-[Cr(NH3)2(NCS)4]− in acetone–water mixtures. The composition of the solvation shell is correlated with the rate of acid hydrolysis of the chromium complex. It emerges that the solvolysis reaction is second order with respect to the solvolytically reactive solvent, water. The mechanistic implications of the rate law are considered as is the significance of analysis of preferential solvation for the determination of kinetic order of solvolytic reactions.

Theoretical Interpretation of High-Performance Chromatographic Data for a Heterogeneous Series of Compounds

1992 ◽  
Vol 57 (1) ◽  
pp. 33-45
Author(s):  
Vladimír Jakuš
Keyword(s):  
Experimental Data ◽  
High Performance ◽  
Theoretical Interpretation ◽  
Retention Data ◽  
Theoretical Evaluation ◽  
New Approach ◽  
Free Energy Of Solvation ◽  
Rp Hplc ◽  
Mobile Phases ◽  
Reversed Phases

A new approach to theoretical evaluation of the Gibbs free energy of solvation was applied for estimation of retention data in high-performance liquid chromatography on reversed phases (RP-HPLC). Simple and improved models of stationary and mobile phases in RP-HPLC were employed. Statistically significant correlations between the calculated and experimental data were obtained for a heterogeneous series of twelve compounds.

Measurement of effective dielectric constant : A comparison

2011 ◽  
Author(s):  
Aakashdeep ◽  
Saurav Kr. Basu ◽  
G. V. Ujjwal ◽  
Sakshi Kumari ◽  
V. R. Gupta
Keyword(s):  
Dielectric Constant ◽  
Effective Dielectric Constant

On the bursting mechanism in rotating rings

1993 ◽  
Vol 28 (3) ◽  
pp. 153-162 ◽  
Author(s):  
C Bandera ◽  
M Nicolich ◽  
A Strozzi
Keyword(s):  
Experimental Data ◽  
Correction Factor ◽  
Static Loading ◽  
Experimental Information ◽  
Theoretical Interpretation ◽  
Dynamic Correction

The bursting mechanism in roatating, bored discs is theoretically reviewed in the light of published experimental information. In particlar, the segmentation sequence in bursting wheels is analysed according to a curved bar modelling and to a quasi-static loading, where a dynamic correction factor is introduced which reconciles theory with experiments. Finally, a diagram reporting the number of wheel fragmented pieces in terms of the ratio of ring inner to outer radii is presented, based upon available experimental data and theoretical interpretation.

scholarly journals Characterization of percolation behavior in conductor–dielectric 0-3 composites

2014 ◽  
Vol 04 (04) ◽  
pp. 1450035 ◽  
Author(s):  
Lin Zhang ◽  
Patrick Bass ◽  
Zhi-Min Dang ◽  
Z.-Y. Cheng
Keyword(s):  
Dielectric Constant ◽  
Percolation Threshold ◽  
Frequency Dependence ◽  
Experimental Results ◽  
Effective Dielectric Constant ◽  
Filler Concentration ◽  
Percolation Behavior ◽  
The Matrix ◽  
The Relationship

The equation ε eff ∝ (ϕc - ϕ)-s which shows the relationship between effective dielectric constant (εeff) and the filler concentration (φ), is widely used to determine the percolation behavior and obtain parameters, such as percolation threshold φc and the power constant s in conductor–dielectric composites (CDCs). Six different systems of CDCs were used to check the expression by fitting experimental results. It is found that the equation can fit the experimental results at any frequency. However, it is found that the fitting constants do not reflect the real percolation behavior of the composites. It is found that the dielectric constant is strongly dependent on the frequency, which is mainly due to the fact that the frequency dependence of the dielectric constant for the composites close to φc is almost independent of the matrix.

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