Kinetics of electrodeposition reactions in mixed solvents—A quantitative description

It is currently well established that, for an Al-Ag alloy quenched from the α phase and aged within the metastable solvus, the aging sequence is: supersaturated α → GP zones → γ’ → γ (Ag2Al). While GP zones and plate-shaped γ’ are metastable phases, continuously distributed in the matrix, formation of the equilibrium phase γ takes place at grain boundaries by discontinuous precipitation (DP). The crystal structure of both γ’ and γ is hep with the following orientation relationship with respect to the fee α matrix: {0001}γ′,γ // {111}α, <1120>γ′,γ, // <110>α.The mechanisms and kinetics of continuous matrix precipitation (CMP) in dilute Al-Ag alloys have been studied in considerable detail. The quantitative description of DP kinetics, however, has received less attention. The present contribution reports the microstructural evolution resulting from aging an Al-Ag alloy with Ag content higher than those previously reported in the literature, focusing the observations of γ' plate-shaped metastable precipitates.

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Kinetic medium effects. IV. Transition state activity coefficients in mixed solvents

Australian Journal of Chemistry ◽

10.1071/ch9720777 ◽

1972 ◽

Vol 25 (4) ◽

pp. 777 ◽

Cited By ~ 1

Author(s):

PT McTigue ◽

AR Watkins

Keyword(s):

Transition State ◽

Activity Coefficients ◽

Mixed Solvents ◽

State Theory ◽

Medium Effects ◽

State Activity ◽

Medium Activity ◽

Solvent Systems ◽

Kinetics Of ◽

Hydrolysis Of

The kinetics of acid hydrolysis of a number of aliphatic acetals have been studied in dimethyl sulphoxide-water and dioxan-water mixtures. Where possible, experimentally measured medium activity coefficients for the acetals in the solvent systems have been used in order to calculate the transition state activity coefficients as a function of solvent composition. These activity coefficients are compared with those calculated for the transition states of other hydrolytic reactions, and with the known activity coefficients of some stable ions. The results show no features inconsistent with the assumptions of transition state theory.

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Dependence of track etching kinetics on chemical reactivity around the ion path

Scientific Reports ◽

10.1038/s41598-019-51748-y ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

S. A. Gorbunov ◽

R. A. Rymzhanov ◽

A. E. Volkov

Keyword(s):

Chemical Reactivity ◽

Quantitative Description ◽

Sample Surface ◽

Numerical Approach ◽

Heavy Ion ◽

Ion Trajectory ◽

Track Etching ◽

Wet Chemical ◽

Kinetics Of ◽

Account Variation

Abstract Etching kinetics of swift heavy ions (SHI) tracks in olivine is investigated in frame of experimentally verified numerical approach. The model takes into account variation of induced chemical reactivity of the material around the whole ion trajectory with the nanometric accuracy. This enables a quantitative description of wet chemical etching of SHI tracks of different lengths and orientations towards to the sample surface. It is demonstrated that two different modes of etching, governed by diffusion of etchant molecules and by their reaction with the material must be observed in experiments using techniques with different resolution thresholds. Applicability limits of the optical microscopy for detection of heavy ion parameters by measuring of the lengthwise etching rates of the ion track are discussed.

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