Kinetics of glass formation

Authors have proposed a novel process not to dispose to landfill sites both waste PVC and waste glass but to utilize them to produce fuel and neutralize each other at the same moment. It has been successfully demonstrated that hydrogen chloride produced during flash pyrolysis of PVC was completely neutralized by the fixed glass bed and thus chlorine-lree fuel was produced [1-2]. To carry forward our proposed process we need to know the kinetics of the neutralization process. Also we have to solve the problem of formation of metal chlorides in the product char during pyrolysis of PVC, which is a critical issue for its thermal utilization. Consequently, in the present study the evaluations of neutralization kinetics of glass cullets and the decomposition of CaCl2 in char by steam were conducted. 

In summary, Fig. 6 exhibits the four characteristic temperatures of glass formation the Arrhenius temperature 7a, the crossover temperature Tj, the ideal glass transition temperature Tb, and a kinetic glass-formation temperature Tg (dehned in Section VI), to illustrate their relative locations with respect to the temperature variation of s. ... 

Experiments indicate that the smooth variations of thermodynamic properties (e.g., V, Ky, and the specific heat at constant pressure Cp) with temperature are intermpted by the kinetic process of glass formation, leading to cooling rate dependent kinks in these properties as a function of temperature. In our view, these kinks cannot be described by an equilibrium statistical mechanical theory, but rather are a challenge for a nonequilibrium theory of glass formation. Nonetheless, some insight into the origin of these kinks and the qualitative... 

Unimolecular films provide a rich area for study in interfacial chemistry which has only been briefly introduced here. Other investigations include the kinetics of film formation, the viscosity of the monolayer, and measurements of surface potential changes [Gl]. Unimolecular films in condensed format may be removed from the surface of the liquid on which they are formed using a glass plate or other suitable solid substrate. The hydrophilic ends of the molecules in the film remain in contact with the solid surface, and the hydrophobic ends, with the air. This type of unimolecular film, which is called a Langmuir-Blodgett film, is also the subject of considerable research interest. 

The answer to our problem is provided by the general kinetic approach to glass formation. The ease of glass formation can be defined... 

D. R. Uhlmann, A kinetic treatment of glass formation, J. Non-cryst. Solids, 7,337-348 (1971). 

A kinetic treatment of glass formation VI1 transient nudeation in non-isothermal crystallization during cooling. J. Non-Cryst. Solids, 50, 189-202. 

TumbuU D (1969) Under what conditions can a glass be formed Contemp Phy 10(5) 473-488 Uhhnann DR (1972) A kinetic treatment of glass formation. J Non-Cryst Sohds 7(4) 337-348 Van den Mooter G, Augustijns P, Kinget R (1999) Stabtiity prediction of amorphous benzodiazepines by calculation of the mean relaxation time constant using the WiUiams-Watts decay function. Eur J Pharm Biopharm 48(l) 43-48... 

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