TY - JOUR
T1 - Applications of thermoanalytical techniques to the study of crystallization kinetics in glass-forming liquids, part I
T2 - Theory
AU - Yinnon, H.
AU - Uhlmann, D. R.
N1 - Funding Information:
Financial support for the present work was provided by the National Science Foundation. This support is gratefully acknowledged, as is the support of the John Simon Guggenheim Foundation, who provided one of the authors (DRU) with a Fellowship for the 1981-1982 year.
PY - 1983/3
Y1 - 1983/3
N2 - A critical review is presented of mathematical methods advanced over the last 20 years for the analysis of data obtained from non-isothermal thermoanalytical studies of crystallization of glass-forming liquids. Methods proposed by Ozawa, Piloyan and Borchardt, Coats, Redfern and Sestak, Ozawa and Chen, Takhor, Kissinger, and Augis and Bennett are examined in detail. All these methods are based on the Avrami treatment of transformation kinetics and define an effective crystallization rate coefficient having an Arrhenian temperature dependence. Several different ways of mathematically treating the data have been proposed. Most are shown to be based on an incorrect neglect of the temperature dependence of the rate coefficient. By taking proper account of the temperature dependence of the crystallization rate coefficient, all the methods are shown to lead to similar conclusions. In detail, it is shown that the effective activation energy of the overall crystallization process can be calculated from the slope of the line obtained by plotting 1n[Q/(TP - T0)] versus 1/TP is the temperature of maximum crystallization rate, TO is an initial temperature and Q is the heating rate employed in the experiment. It is further argued that in general the overall crystallization rate coefficient is not Arrhenian in character. Thus, in general, non-isothermal transformation cannot be treated analytically. A detailed description of nonisothermal transformation can, however, be obtained by numerical methods. Such a method is described and its uses in obtaining kinetic data from thermoanalytical studies are demonstrated.
AB - A critical review is presented of mathematical methods advanced over the last 20 years for the analysis of data obtained from non-isothermal thermoanalytical studies of crystallization of glass-forming liquids. Methods proposed by Ozawa, Piloyan and Borchardt, Coats, Redfern and Sestak, Ozawa and Chen, Takhor, Kissinger, and Augis and Bennett are examined in detail. All these methods are based on the Avrami treatment of transformation kinetics and define an effective crystallization rate coefficient having an Arrhenian temperature dependence. Several different ways of mathematically treating the data have been proposed. Most are shown to be based on an incorrect neglect of the temperature dependence of the rate coefficient. By taking proper account of the temperature dependence of the crystallization rate coefficient, all the methods are shown to lead to similar conclusions. In detail, it is shown that the effective activation energy of the overall crystallization process can be calculated from the slope of the line obtained by plotting 1n[Q/(TP - T0)] versus 1/TP is the temperature of maximum crystallization rate, TO is an initial temperature and Q is the heating rate employed in the experiment. It is further argued that in general the overall crystallization rate coefficient is not Arrhenian in character. Thus, in general, non-isothermal transformation cannot be treated analytically. A detailed description of nonisothermal transformation can, however, be obtained by numerical methods. Such a method is described and its uses in obtaining kinetic data from thermoanalytical studies are demonstrated.
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U2 - 10.1016/0022-3093(83)90069-8
DO - 10.1016/0022-3093(83)90069-8
M3 - Article
AN - SCOPUS:0020717184
SN - 0022-3093
VL - 54
SP - 253
EP - 275
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
IS - 3
ER -