Preferential solvation and elasticity of the hydrogen bonds network in tertiary butyl alcohol–water mixture

Molecular dynamics simulations have been performed for water–tertiary butyl alcohol (TBA) mixtures in the water rich region. Examination of the Kirkwood–Buff integrals, local composition, and potential mean force for concentration in the range 0.05–0.07 TBA mole fraction leads to insight into the unexpected behaviors of some thermodynamics properties. Hydrophobic hydration phenomena and solvent–solute association are discussed at the molecular level. Since the hydrogen bond network elasticity modulus is a quantitative measure of the resistance of the water hydrogen bonds network to external perturbation arising from solvent–solute interactions, a first principle calculation of the elasticity modulus was carried out.