Solvation energy of water

Li+ (0.77) < Na+ (1.0) < K+ (1.48) < Rb+ (1.55) < Cs+ (1.56). While indeed the order is the same, the significant point is that the range of discrimination has been expanded by almost an order of magnitude. The concern then becomes the mechanism whereby the Gramicidin channel effects this enhancement of selectivity. An important source of selectivity that must be considered is the relative solvation energy of water... 

In the presence of DMSO, the AG values are equal to 5-6 kJ/mol for the majority of samples of native human bone tissue and protein or mineral components of water in DMSO in the interfacial layers under action of the surface forces of the materials. Taking into account that the heat effect of water crystallization is 4 kJ/mol, one can conclude that the solvation energy of water in DMSO (J< 273 K) is higher than the interaction energy of water with functionalities of both protein and mineral components of bone tissue. 

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