Dependence of the thermodynamic characteristics of the hydration and solvation of ions on temperature and the composition of the mixed solvent

1984 ◽  
Vol 25 (2) ◽  
pp. 258-259
Author(s):  
V. V. Aleksandrov ◽  
V. I. Lebed
Keyword(s):  
Mixed Solvent ◽  
Thermodynamic Characteristics ◽  
Solvation Of Ions

Conductance Study of Benzyl Bromide Reaction with Cyclicamines in Aqueous-Ethanol Medium

2018 ◽  
Vol 7 (3.3) ◽  
pp. 143
Author(s):  
Veerati Radhika ◽  
. .
Keyword(s):  
Electrostatic Interactions ◽  
Mixed Solvent ◽  
Aqueous Ethanol ◽  
Benzyl Bromide ◽  
Frontier Molecular Orbital ◽  
Orbital Interactions ◽  
R Factor ◽  
Ethanol Medium ◽  
Solvation Of Ions ◽  
Homo Lumo

Nucleophilic substitution reaction of benzyl bromide and cyclicamines in ethanol aqueous intermediate reactivity can suggest that the nucleophile increases through their pKa values. A linear correlation exists between computed values of the dipole moment, rate and electronegativity of the nucelophiles. The two reactants suggest that frontier molecular orbital interactions ion-solvation and correlation of time with the HOMO-LUMO breach of that the reaction.  But it is not orbital controlled as well as forbidden by the electrostatic interactions along with mixed solvent composition between the reactants. The influence on the solvation of ions before reaction has been discuss with facilitate by R-factor. Thermodynamic properties are evaluate and report. The consequences of the learning to be interpreted in terms of ion-solvent exchanges and solvent properties comparing with electrostatic interaction between the reactants.   

ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

2019 ◽  
pp. 56-66
Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Titanium Carbide ◽  
Temperature Dependence ◽  
Carbon Concentration ◽  
Room Temperature ◽  
Thermodynamic Characteristics ◽  
Liquid Nitrogen Temperature ◽  
Analysis Data ◽  
Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

Solvation of ions by dipolar aprotic solvents and water. A CNDO/2 study

1985 ◽  
Vol 50 (11) ◽  
pp. 2493-2508 ◽  
Author(s):  
Petr Kyselka ◽  
Zdeněk Havlas ◽  
Ivo Sláma
Keyword(s):  
Binary Mixtures ◽  
Quantum Chemical ◽  
Chemical Method ◽  
Molecular Structures ◽  
Dimethyl Sulphoxide ◽  
Ternary Mixtures ◽  
Aprotic Solvents ◽  
Quantum Chemical Method ◽  
Solvation Of Ions ◽  
Dipolar Aprotic Solvents

Solvation of Li+, Be2+, Na+, Mg2+, and Al3+ ions has been studied in binary mixtures with dimethyl sulphoxide, dimethylformamide, acetonitrile and water, and in ternary mixtures of the organic solvents with water. The CNDO/2 quantum chemical method was used to calculate the energies of solvation, molecular structures and charge distributions for the complexes acetonitrile...ion (1:1, 2:1, 4:1), dimethyl sulphoxide...ion (1:1), dimethylformamide...ion (1:1), and acetonitrile (dimethyl sulphoxide, dimethylformamide)...ion...water (1:1:1).

Study of Sedimentation Velocity of Block Copolymer Micelles

1993 ◽  
Vol 58 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Minmin Tian ◽  
C. Ramireddy ◽  
Stephen E. Webber ◽  
Petr Munk
Keyword(s):  
Block Copolymer ◽  
Methacrylic Acid ◽  
Mixed Solvent ◽  
Hard Spheres ◽  
Sedimentation Velocity ◽  
Hydrodynamic Coefficient ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Size Heterogeneity ◽  
Good Agreement

No anomalies were observed during the measurement of sedimentation coefficients of block copolymer micelles formed by copolymers of styrene and methacrylic acid in a mixed solvent; 80 vol.% of dioxane and 20 vol.% of water. The shapes of the sedimenting boundaries suggest that the size heterogeneity of the micelles is small. Linear relations between 1/s and c were obtained. The value of the hydrodynamic coefficient κ was between 2 and 4 in a good agreement with the value 2.75 or 2.86 that was obtained by combining Burgers' or Fixman's values of the coefficient of the concentration dependence kvs for hard spheres with Einstein's value of [η] for spheres.

Nanoporous polyethersulfone membranes prepared by mixed solvent phase separation method for protein separation

2021 ◽  
pp. 119507
Author(s):  
Peipei Li ◽  
Roshni L. Thankamony ◽  
Xiang Li ◽  
Zhen Li ◽  
Xiaowei Liu ◽  
...  
Keyword(s):  
Phase Separation ◽  
Protein Separation ◽  
Mixed Solvent ◽  
Separation Method ◽  
Solvent Phase
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