Glasses dynamics

Chirife, J. and Buera, M.B. 1996. Water activity, water glass dynamics, and the control of microbiological growth in foods. Crit. Rev. Food Sci. Nutr. 36, 465-513. 

Fig. 3.22 Frequency-dependent dynamic modulus G"(co) from a PE chain of M =800 kg/mol at 509 K. The solid line gives the reptation prediction of G co)-cor . The peak here may not be confused with the a-relaxation of the glass dynamics. It immediately follows from the Fourier transform of strongly depends on molecular weight. The glass relaxation...

SUPERPARAMAGNETISM AND SPIN GLASS DYNAMICS OF INTERACTING MAGNETIC NANOPARTICLE SYSTEMS... 

Superparamagnetism and Spin Glass Dynamics of Interacting Magnetic Nanoparticle Systems By Petra E. Jonsson... 

Figure 1-23 Relationship Between Water Activity aw) and Glass Transition Temperature (Tg) of Some Plant Materials and Biopolymers. Source Reprinted with permission from J. Cherife and M. del Pinar Buera, Water Activity, Water Glass Dynamics and the Control of Microbiological Growth in Foods, Critical Review Food Sci. Nutr., Vol. 36, No. 5, p. 490, 1996. Copyright CRC Press, Boca Raton, Florida.

The glass transition processes in foods may result from a rapid removal of water from solids. Based on that, e.g., the Tg values of anhydrous polysaccharides are high, and the food materials may decompose at temperatures below Tg (Kokini et al 1994 Roos and Karel, 1991b). The glass temperature transition affects viscosity, stickiness, crispness, collapse, crystallization, and ice formation, and can strongly influence deteriorative reaction rates. This provides a new theoretical and experimental framework for the study of food systems to unify structural and functional aspects of foods, described in terms of water dynamics and glass dynamics. 

The term water dynamics indicates the mobility of the plasticizing diluent and a theoretical approach to understanding how to control the water movement in glassforming food systems. The term glass dynamics deals with the time and temperature dependence of relationships among composition, structure, and thermomechanical properties, as well as the functional behavior of food systems. 

The functional aspects, in terms of water dynamics and glass dynamics, and the appropriate kinetic description of the nonequilibrium thermomechanical behavior of food systems have been illustrated as a dynamics map, shown in Figure 8.13. 

These unified concepts, based on water dynamics and glass dynamics, have been used to explain and predict the functional and rheological properties of food systems during processing and their effects on time-dependent structural and mechanical factors related to quality and storage stability of food microstructures. 

Keywords Colloidal dispersions Colloidal glasses Dynamics Grafted particles Hairy particles Micelles Nanoparticle-polymer hybrids Phase diagrams Polymers Rheology Soft colloids- Softness Stars... 

Cresyl violet in ethanol at 1.3K has been used to probe low temperature glass dynamics by the fast generation and detection of optical holes. Relaxation processes of the 3,3 -diethyloxadicarbocyanine iodide (DODCI) photoisomer have been characterised spectroscopically. ... 

Soles CL, Tsai AM, Cicerone MT (2006) Glass dynamics and the preservation of proteins. In Murphy RM, Tsai AM (eds). Misbehaving proteins. Springer, New York, pp 193-214 Spok A (2006) Safety regulations of food enzymes. Food Technol Biotechnol 44(2) 197-209 Stuart WD, Ivy JM, Koo K (1997) Neurospora expression system. US Patent 5695965, 9 December 1997... 

Theoretical Basis of the Characterization Method - Tg Glass Dynamics the State Diagram as a Dynamics Map Used to Trace "Collapse" Phenomena in Foods... 

Glass dynamics deals with the time- and temperature-dependence... 

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