Gibbs free energy glass

Fig. 25. Relationship between the measured interfacial strength and the (negative) Gibbs free energy of mixing, (-AG )o5, for glass beads treated with various silane coupling agents embedded in a PVB matrix. Error bars correspond to 95% mean confidence intervals. Redrawn from ref. [165].

We also note that the values obtained for the prefactor Q are the same for room-temperature and low-temperature glass also, in both glasses, the values of are about two orders of magnitude lower than in the case of bare protoheme. This latter difference was interpreted by Ye et al. (2007) as entropic control in the protein. This idea may be rationalized upon glancing at Equation (1.1), which predicts that, if not used explicitly in data analysis, a possible entropic contribution to the change in Gibbs free energy would be collected in the prefactor Q. 

Gibbs energy See free energy. glass An ionic solid with an amorphous structure resembling that of a liquid. 

The glass transition is characterized in part by an observed second-order transition distinguished by a discontinuity of the Gibbs free energy with respect to the aforementioned state variables, but by continuity of entropy, volume, and enthalpy. Hence, heat capacity, Cp, as well as the thermal expansion coefficient, a, as defined below, both exhibit a discontinuity at the glass transition temperature (McKenna, 1989). 

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