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Introduction Iso-conversional methods are used for non-isothermal analysis, in which the transformation rate at a constant extent of conversion is only a function of temperature as suggested by Vyazovkin et al. [ 1 – 4 ] and
method, which can not detect the complex nature of the solid-state reaction, has been replaced by multiple scan method at different heating rates using iso-conversional and iso-temperature calculation procedures [ 12 – 14 ]. Among the iso-conversional
Abstract
The kinetics of bovine serum albumin (BSA) denaturation in the absence and the presence of urea was studied by the iso-conversional method and the master plots method using differential scanning calorimetry (DSC). The observed denaturation process was irreversible and approximately conformed to the simple order reaction, and the denaturation did not follow rigorously first-order kinetic model or other integral order reaction models. The denaturation temperature (T m), apparent activation energy (E a), approximate order of reaction (n), and pre-exponential factor (A) all distinctly decreased as the 2 mol L−1 urea was added, which indicated that the urea accelerated the denaturation process of BSA and greatly reduced thermal and kinetic stability of BSA. This study also demonstrated that the iso-conversional method, in combination with the master plots method, provides a valuable and useful approach to the study of the kinetic process of protein denaturation.
Abstract
The kinetics of protein thermal transition is of a significant interest from the standpoint of medical treatment. The effect of sucrose (0–15 mass%) on bovine serum albumin denatured aggregation kinetics at high concentration was studied by the iso-conversional method and the master plots method using differential scanning calorimetry. The observed aggregation was irreversible and conformed to the simple order reaction. The denaturation temperature (T m), the kinetic triplets all increased as the sucrose concentration increased, which indicated the remarkable stabilization effect of sucrose. The study purpose is to provide new opportunities in exploring aggregation kinetics mechanisms in the presence of additive.
whole course of the cross-linking reactions, they tend to produce highly uncertain kinetic predictions for rather complex cure mechanisms. Model-free (or iso-conversional) kinetic methods on the other hand rely on conversion-dependent, non
Some transition metal nitrate complexes with hexamethylenetetramine
Part LV. Preparation, X-ray crystallography and thermal decomposition
Abstract
Three hexamethylenetetramine (HMTA) metal nitrate complexes such as [M(H2O)4(H2O-HMTA)2](NO3)·4H2O (where M=Co, Ni and Zn) have been prepared and characterized by X-ray crystallography. Their thermal decomposition have been studied by using dynamic, isothermal thermogravimery (TG) and differential thermal analysis (DTA). Kinetics of thermal decomposition was undertaken by applying model-fitting as well as isoconversional methods. The possible pathways of thermolysis have also been proposed. Ignition delay measurements have been carried out to investigate the response of these complexes under condition of rapid heating.
methods of analysis of thermo-gravimetric curves were used, which are based on the Coats–Redfern equation: model fixing [ 11 ], and iso-conversional methods. In general, the rate law of a decomposition reaction in the solid state is expressed as dα/dt = A
Kinetics and safety analysis of sulfide mineral self-heating
Part 1. Effect of mineralogy
probability in terms of time to maximum rate under adiabatic conditions. In continuation of our research on sulfide mineral self-heating behavior [ 1 , 2 ], we report in this paper thermal safety prediction of self-heating based on iso-conversional
Catalytic effect of bases in impregnation of guanidine nitrate on Poplar (Populus) wood
Flammability and multiple heating rate kinetic study
calculated by “model free” iso-conversional methods. The methods used in calculating activation energy at different conversions ( α ) were Ozawa–Flynn–Wall (O–F–W) [ 12 , 13 ] and Coats–Redfern (modified) [ 14 ]. The final equations used for calculation of
the following steps [ 25 , 26 ]: (i) Assume h ( x ) = 1 or H ( x ) = 1 to estimate the initial value of the activation energy E a1 . The conventional iso-conversional methods stop the calculation at this step; (ii) using E a1 , calculate a new
