Acid-base interactions free energy

Peppas et al. divided the free energy change, g23, into three components originating from (i) dispersive forces (g23), (ii) the acid-base interactions (g23) and (iii) the hydrophobic effect (g23). 

Given that AH = —254.4 kJ mol-1 and S° = 14.81 J K-1 mol-1 for hexagonal solid boron nitride, use the data of Appendix C to calculate the free energy change for the hydrolysis of one mole of BN (s) by liquid water at 25 °C. Ignore the weak acid-base interaction of the products and the very slight solubility of B(OH)3(s). 

For test substance free energy of adsorption (AG ) is the sum of energies of adsorption attributed to dispersive and specific interactions. Adsorption of non-polar probes as n-alkanes is caused by dispersive interactions, whereas for polar probes both London and acid-base interactions contribute to AG ... 

Fowkes and Mostafa (51) demonstrated another fruitful approach to the problem of estimating surface energies of solids by separating the surface free energy into different components, of which dispersive and polar acid-base interactions dominate, thus giving the following ... 

In other words, the total potential energy of nanoparticle-liquid interactions is the sum of a Lifshitz-van der Waals interaction (y ), which means the surface free energy (dipole-dipole and dipole-induced dipole interaction), and Lewis acid-base interaction (y ). The Lewis acid-base interaction (y ) for the component i is simply calculated by the geometric mean of electron acceptor (y ) and donor (y ) ... 

Several probes are used to obtain the relationship between RTlnVN and ay. From this relationship the reference retention volume,, is calculated and used to calculate the acid-base interaction s contribution to the free energy of desorption ... 

Figure 10.1.7 shows the correlation between the number of carbon atoms in n-aUcanes and the net retention volume of solvent using IGC measurements. Such a correlation must be established to calculate the acid-base interaction s contribution to the free energy of desorption, AGab, as pointed out in discussion of equations [10.1.5] and [10.1.6]. Figure 10.1.8 shows that the Flory interaction parameter (measured by IGC) increases as the temperature increases. 

The thermodynamic model of adhesion, generally attributed to Sharpe and Schonhom [1], is certainly the most widely used approach in adhesion science nowadays. This theory considers that the adhesive will adhere to the substrate because of interatomic and intermolecular forces established at the interface, provided that an intimate contact between both materials is achieved. The most common interfacial forces result from van der Waals (London, Debye and Keesom) and Lewis acid-base interactions. The magnitude of these forces can generally be related to fundamental thermodynamic surface characteristics, such as surface free energies y, of both materials in contact. 

All other polar probes exhibit higher net retention volumes, En. and the difference between their net retention volume and that of the n-alkanes for the same value of the dispersive component of surface energy leads to the value of the free energy of desorption, AGjp, corresponding to the specific acid-base interaction, expressed as ... 

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