Search results
Results from the WOW.Com Content Network
Recrystallization kinetics are commonly observed to follow the profile shown. There is an initial 'nucleation period' t 0 where the nuclei form, and then begin to grow at a constant rate consuming the deformed matrix. Although the process does not strictly follow classical nucleation theory it is often found that such mathematical descriptions ...
The equation was first derived by Johnson, Mehl, Avrami and Kolmogorov (in Russian) in a series of articles published in the Journal of Chemical Physics between 1939 and 1941. [2] [3] [4] Moreover, Kolmogorov treated statistically the crystallization of a solid in 1937 (in Russian, Kolmogorov, A. N., Izv. Akad. Nauk. SSSR., 1937, 3, 355).
In physical chemistry, the Arrhenius equation is a formula for the temperature dependence of reaction rates.The equation was proposed by Svante Arrhenius in 1889, based on the work of Dutch chemist Jacobus Henricus van 't Hoff who had noted in 1884 that the van 't Hoff equation for the temperature dependence of equilibrium constants suggests such a formula for the rates of both forward and ...
Recrystallization is a method used to purify chemicals by dissolving a mixture of a compound and its impurities, in an appropriate solvent, prior to heating the solution. [1] Following the dissolution of crude product, the mixture will passively cool, yielding a crystallized compound and its impurities as separate entities.
The methods used to determine the degree of crystallinity can be incorporated over time to measure the kinetics of crystallization. The most basic model for polymer crystallization kinetics comes from Hoffman nucleation theory. The crystallization process of polymers does not always obey simple chemical rate equations. Polymers can crystallize ...
Dynamic recrystallization (DRX) is a type of recrystallization process, found within the fields of metallurgy and geology. In dynamic recrystallization, as opposed to static recrystallization, the nucleation and growth of new grains occurs during deformation rather than afterwards as part of a separate heat treatment.
The Eyring equation (occasionally also known as Eyring–Polanyi equation) is an equation used in chemical kinetics to describe changes in the rate of a chemical reaction against temperature. It was developed almost simultaneously in 1935 by Henry Eyring , Meredith Gwynne Evans and Michael Polanyi .
The Van 't Hoff equation relates the change in the equilibrium constant, K eq, of a chemical reaction to the change in temperature, T, given the standard enthalpy change, Δ r H ⊖, for the process. The subscript r {\displaystyle r} means "reaction" and the superscript ⊖ {\displaystyle \ominus } means "standard".