The Experts below are selected from a list of 2958 Experts worldwide ranked by ideXlab platform
Jiři Malek - One of the best experts on this subject based on the ideXlab platform.
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testing method for the johnson mehl Avrami Equation in kinetic analysis of crystallization processes
Journal of the American Ceramic Society, 2004Co-Authors: Jiři Malek, Takefumi MitsuhashiAbstract:The kinetics of crystallization processes in solids are usually described by the Johnson–Mehl–Avrami Equation. One of the most popular methods to test the applicability of this Equation is based on a double logarithmic plot of fraction crystallized (α). However, such plot is not very sensitive to small changes in α, and its reliability is rather limited. A simple and convenient testing method based on rate data (dα/dt) is proposed. The method can be applied to virtually any type of kinetic data obtained under isothermal or nonisothermal conditions.
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the applicability of johnson mehl Avrami model in the thermal analysis of the crystallization kinetics of glasses
Thermochimica Acta, 1995Co-Authors: Jiři MalekAbstract:The Johnson-Mehl-Avrami Equation is frequently used for analysis of experimental data of non-isothermal crystallization kinetics although this theoretical model has limited applicability for the non-isothermal transformations involving nucleation and growth. It is shown that the applicability of this model should be tested by reliable methods before a quantitative analysis of non-isothermal crystallization data is made. Such testing methods are described and their uses are demonstrated.
Shernlong Lee - One of the best experts on this subject based on the ideXlab platform.
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dynamics of supramolecular crystal growth at the liquid solid interface studied via scanning tunneling microscope and the Avrami Equation
Journal of Physical Chemistry C, 2021Co-Authors: Xingming Zeng, Lihua Wang, Bolun Fang, Sadaf Bashir Khan, Shernlong LeeAbstract:We report the study of supramolecular assembling from both experimental and theoretical points of view. A scanning tunneling microscope (STM) and the Johnson–Mehl–Avrami (JMA) Equation were, respec...
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dynamics of supramolecular crystal growth at the liquid solid interface studied via scanning tunneling microscope and the Avrami Equation
The Journal of Physical Chemistry, 2021Co-Authors: Xingming Zeng, Lihua Wang, Bolun Fang, Sadaf Bashir Khan, Shernlong LeeAbstract:We report the study of supramolecular assembling from both experimental and theoretical points of view. A scanning tunneling microscope (STM) and the Johnson–Mehl–Avrami (JMA) Equation were, respectively, used to reveal and to explain the “STM-directed” self-assembling of p-terphenyl-3,5,3′,5′-tetracarboxylic acid (TPTC) at the liquid–solid interface. The Avrami index helps in providing significant information regarding the surface supramolecular crystalline framework. It also helps us to calculate the domains of crystal growth, to distinguish the crystal development to be homogenous or heterogeneous, as well as to identify the dimension of the crystal growth. The JMA Equation was also used to evaluate whether (i) the close-packing crystal of TPTC can develop into a single crystal or (ii) the porous networks of TPTC may hinder the close packing to form during its progression.
Mike J Jenkins - One of the best experts on this subject based on the ideXlab platform.
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the effect of a secondary process on polymer crystallization kinetics 3 co poly lactic acid
European Polymer Journal, 2017Co-Authors: Azizan A Aziz, Sani Amril Samsudin, Mike J JenkinsAbstract:Abstract The crystallization kinetics of a copolymer of l -lactic acid with 4% d -lactic acid has been studied using FTIR spectroscopy by measuring the absorbance of the crystalline carbonyl stretching band at 1759 cm−1. Copolymerization greatly reduced the rate of crystallization and the technique directly measured the relative crystallinity over extended periods with sufficient accuracy to test the validity of the Avrami Equation. This was modified to account for the simultaneous presence of a secondary process from the onset of crystallization, such that the overall fractional crystallinity, Xt, is related to the lapsed time, t, by. X t = X p , ∞ ( 1 - exp - Z p t n ) 1 + k s t 1 2 where Xp,∞ is the final fractional crystallinity achieved by the primary process, Zp is the primary composite rate constant incorporating nucleation and growth, and ks is the secondary rate constant. The additional crystallinity produced by the secondary processes is sufficient to account for the observed fractional constant n values on analysis of the total development of crystallinity with time. It was concluded that the analysis using the Avrami Equation should be restricted to the time dependence of the crystallinity produced by the primary process alone.
Xingming Zeng - One of the best experts on this subject based on the ideXlab platform.
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dynamics of supramolecular crystal growth at the liquid solid interface studied via scanning tunneling microscope and the Avrami Equation
Journal of Physical Chemistry C, 2021Co-Authors: Xingming Zeng, Lihua Wang, Bolun Fang, Sadaf Bashir Khan, Shernlong LeeAbstract:We report the study of supramolecular assembling from both experimental and theoretical points of view. A scanning tunneling microscope (STM) and the Johnson–Mehl–Avrami (JMA) Equation were, respec...
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dynamics of supramolecular crystal growth at the liquid solid interface studied via scanning tunneling microscope and the Avrami Equation
The Journal of Physical Chemistry, 2021Co-Authors: Xingming Zeng, Lihua Wang, Bolun Fang, Sadaf Bashir Khan, Shernlong LeeAbstract:We report the study of supramolecular assembling from both experimental and theoretical points of view. A scanning tunneling microscope (STM) and the Johnson–Mehl–Avrami (JMA) Equation were, respectively, used to reveal and to explain the “STM-directed” self-assembling of p-terphenyl-3,5,3′,5′-tetracarboxylic acid (TPTC) at the liquid–solid interface. The Avrami index helps in providing significant information regarding the surface supramolecular crystalline framework. It also helps us to calculate the domains of crystal growth, to distinguish the crystal development to be homogenous or heterogeneous, as well as to identify the dimension of the crystal growth. The JMA Equation was also used to evaluate whether (i) the close-packing crystal of TPTC can develop into a single crystal or (ii) the porous networks of TPTC may hinder the close packing to form during its progression.
S. W. Kim - One of the best experts on this subject based on the ideXlab platform.
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dynamic dsc characterization of epoxy resin by means of the Avrami Equation
Journal of Thermal Analysis and Calorimetry, 1999Co-Authors: M. J. Shim, S. W. KimAbstract:A phenomenological approach was used to characterize the cure processes of epoxy resins (a diglycidyl ether of bisphenol A and its modifier CTBN) from dynamic experiments by DSC. Various kinetic parameters were obtained by using a modified Avrami expression. The resulting overall activation energies for the two systems agreed very well with the published data in the whole cure temperature range. In contrast with the isothermal results and the general dynamic models, a change in the exponent and the non-linear temperature dependence of the rate constant were also observed.
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Curing behavior of an unsaturated polyester system analyzed by Avrami Equation
Thermochimica Acta, 1998Co-Authors: M. J. Shim, S. W. KimAbstract:The isothermal cure behavior of an unsaturated polyester resin system is studied by differential scanning calorimetry. The reaction heats (at different curing temperatures) are presented and compared to the results of the previous studies. Various kinetic parameters as well as details of the curing process can be obtained and elucidated, based on the Avrami theory. The experimental results reveal that this analytical method is valid for describing the curing behavior of unsaturated polyester resins.
