Melting, thermodynamics

One implication of the ability of the database to make reasonable predictions about the thermodynamics of duplex melting is that base sequence, rather than total base composition, determines duplex stability. This conclusion is supported by the observation that the second and third entries in Table 16.6, which involve only A and T, have the same base composition but yield significantly different melting thermodynamics. 

We will conclude with a description of how the database can be used to provide baseline values for normal duplexes against which to compare the melting thermodynamics observed in duplexes that have been altered by ligand binding, crosslinking, or other effects. 

This seetion will deseribe the eurrent status of research in two different aspects of nanocrystal phase behaviom melting and solid-solid phase transitions. In the case of melting, thermodynamic considerations of smface energies can explain the redueed melting point observed in many nanoerystals. Strictly thermodynamic models, however, are not adequate to deseribe solid-solid phase transitions in these materials. 

Simha, R., Polymer and oligomer melts, thermodynamics, correlations, and lattice-hole theory. Polymer Engineering and Science, 36(12), pp. 1567-1573 (1996). 

Jiang Q, Shi HX, Zhao M. Melting thermodynamics of organic nanocrystals./. Chem. Phys. 1999 111 2176-2180. 

In the Flory-Huggins description of polymer melt thermodynamics, the interactions between segments, depending only on the local concentration of the different types of chemical functions, constitute the enthalpy contribution, whereas the entropy is a non-local contribution, depending on the number of allowed conformation of the entire copolymer chains [27, 28]. Entropy is related to elasticity and will be optimized when all tensions are released within the chains. 

Hug] Method of distribution copper between liquid silver and C-Cu melts. Thermodynamic calculation of interaction parameters The activity of copper in melt (0 to 25) mass% C-(0 to 25) mass% Cu-Fe, 1550°C... 

Having determined the structure of the polymer liquid, it is in principle possible to compute most thermodynamic properties of interest. Whereas the structure or radial distribution functions at liquid density are primarily controlled by the repulsive part of the intersite potentials, thermodynamic quantities will also be sensitive to the attractive potentials. In the case of a one-component melt, thermodynamic quantities of interest include the pressure P, isothermal compressibility k, and the internal or cohesive energy U. Since in general one theoretically knows g(r) only approximately, the thermodynamic properties derived from structure will be approximate. Moreover, integral equation theory leads to thermodynamically inconsistent results in the sense that the predictions depend on the particular thermodynamic route used to relate the thermodynamic quantity to the structure. ... 

Kammer H-W (1977) Surface and interfacial tension of polymer melts - thermodynamic theory of interface between immiscible polymers. Z Phys Chem (Leipzig) 258 1149-1161... 

The focal point of s section pertains to the strong correlation between enthalpy and entropy changes observed for the dissociation/association of DNA base pairs and their next nearest neighbours impact on a particular base pair. In short this is called enthalpy-entropy compensation in DNA melting thermodynamics. 

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