Non-equilibrium glassy state

Experience has shown that these films must have a high glass transition temperature, Qrpically > 180 C, to insure thermal stability for many years. An important focus of current research is therefore directed to the enhancement of the thermal and temporal stability of x X The stability of polar order in the thermodynamically non-equilibrium glassy state varies from polymer to polymer. Chemical attachment of the chromophore to the polymer as a sidechain (2), as part of the mainchain (J), orinacrosslinkedstructure(4), has been found to retard the relaxaticm of alignment... 

In the study on enthalpy relaxation, we studied the response of polymers subjected to aging in a non-equilibrium (glassy) state. We monitored relaxation of... 

The glassy state of materials prepared under normal conditions is in a non-equilibrium state, in which an excess volume and enthalpy exist. When such a non-equlibrium glassy state is held at temperatures a few degrees lower than T, the excess thermodynamic properties decrease to those of an ideally equilibrium state. At the same time, the mechanical properties of the materials change (lOj. 

Therefore, Equations 1.20 and 1.21 are fulfilled for polymers simultaneously, i.e., suprasegmental structure formation represents a non-equilibrium transition resulting in formation of non-equilibrium structures. It is significant that the beginning of their formation corresponds to the glass transition, i.e., to the transition from an equilibrium devitrified state to a weakly non-equilibrium glassy one. 

Various authors have considered the glassy state behaviour, and in particular the sorption of gases and supercritical fluids. The main dificulty is to find a thermodynamic model suitable for the description of the properties of the glassy state. Also, the normal equations of state specially developed for polymeric systems are not directly applicable to the non-equilibrium conditions of this state. 

Tsuji, K., Sorai, M. and Seki, S. New finding of glassy liquid crystal — a non-equilibrium state of cholesteryl hydrogen phthalate. Bull. Chem. Soc., Japan 44, 1452 (1971)... 

The kinetic character of the glass transition and the resulting non-equilibrium character of the glassy state are responsible for the phenomena of structural relaxation, glass transition hysteresis, and physical aging (Kovacs, 1963 Struik, 1978). 

Ono and Ware"" have measured the absorption, emission, and excitation spectra, the fluorescence decay times, and the quantum yields of a series of substituted diphenylmethylenes in rigid matrices at low temperatures. Acean-thrylene shows S2- So emission in hexane with a yield of 0.017 and lifetime of 4.3 ns. The low-temperature fluorescence spectra of bis-2-naphthyl-alkanes and their derivatives have been studied. Excimer formation is an activated process. The fluorescence and absorption spectra of 1,1-diphenyl-ethylenes have been analysed in some detail by Gustav and Bolke. " The S — Si transitions in trans isomers of phenylnaphthylethylenes have been assigned by picosecond absorption spectroscopy. Effects of solvent viscosity and the role of conformers in the mechanism of isomerization are elucidated. The production of non-equilibrium conformer concentrations in glassy solutions of diarylethylenes at 77 K due to restrictions imposed by the solid matrix has also been reported. Free jet excitation and emission spectra of diphenyl-butadiene show clearly the lowest excited Ag state and give a lifetime of 52.8 ns for 0-0 excitation.Electric field-induced charges in the optical... 

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