Search Results
separate overlapping transitions when one transition goes into the reversing signal and the other into the nonreversing signal. But what if both go into the reversing signal such as a melting transition overlapping a glass transition due to a phase
glass transition kinetics of metallic alloys is of great importance to know its thermal stability, and finally to determine the useful range of operating temperatures for a specific technological application before the crystallization takes place [ 4
The glass transition
Finite size effect
Abstract
The subjects of the paper are the mechanism of vitrification and the glass transition, and a definition of the temperature of the glass transition. A comprehensive description of the structural changes occurring in the amorphous phase (‘real’ and ‘semi-ordered’) in a vicinity of the glass transition is presented. One of the major motivation of our studies is to investigate the finite size effect of the glass transition that could be related to the cooperative motion in supercooled liquids. Also, new formula, describing the relaxation time temperature change, is applied in order to better reveal themechanismof the supermolecular formation under different internal and external factors. The results of the basic methods of thermal analysis, obtained for different polymeric systems, were used in this study. The proposed approach let us correlate the thermodynamic and the structural parameters, which are estimated from the experiments, and describe all well known shapes of the DSC traces, which can be recorded in the glass transition region. Based on positron annihilation lifetime spectroscopy and dilatometric results, the significance of the free and the specific volumes for the activation of the relaxing units is discussed.
crystallographic phases, some of which are stabilized only under high pressure or recovered by decomposition to atmospheric pressure. The size-dependent glass transition is an important parameter for any phase transition process and is related to the
focus on the effects of size and shape on melting, glass transition, and Kauzmann temperatures of SnO 2 nanoparticles. The size-dependent glass transition is an important parameter for any phase transition process and is related to the thermodynamical
semiconducting chalcogenide glasses is crucial to understand their properties and functions. In fact, the understanding of glass transition kinetics of chalcogenide glasses aims at establishing their thermal stability and glass-forming ability (GFA). This enables
harder than amorphous Se. They also have higher glass transition and crystallization temperatures and a smaller ageing effect than pure amorphous Se [ 5 ]. Moreover, addition of third element such as In to binary chalcogenide glass produces a higher
study, we investigate the thermodynamic properties in the range of the glass transition temperature, T g . As reported, bound water plasticizes the silk fibroin films inducing a low T g during heating, and the water content within the silk film
state. Vitrification is the point at which the resin changes from the rubbery state to the solid glassy state. The TTT diagram may be augmented by adding iso-conversion, iso-glass transition temperature (iso- T g ), and iso-viscous contours as well as
Abstract
Enthalpic relaxation has been used to model the development of the glass transition in polymers, using kinetic parameters
determined separately. For this purpose the Kohlrausch-Williams-Watt stretched exponential function, relating the extent of
relaxation, Φ(t), to time t and an average relaxation time, τa, i.e.
