Thermodynamic study of (perfluoroalkane + alkane) mixtures : Excess and solvation enthalpies

摘要: Abstract A newly designed calorimetric technique and calculation procedure have been used to obtain partial molar enthalpies, H ¯ i , excess HE, for binary mixture of hexane + perfluoro-n-alkanes (C5–C8) perfluorohexane + n-alkanes (C5–C8), + cyclohexane, + 2-methylheptane. All mixtures are endothermic, the heat effects increase with size second component. The HE values found largest ever observed non-polar compounds. An estimate capacity (perfluorohexane + 2-methylheptane) has obtained from at two different temperatures. From infinite dilution known enthalpies vaporization, solvation, ΔsolvH∘, evaluated either alkanes perfluoroalkanes in both hexane perfluorohexane solvent. Solute–solvent interactions examined by describing ΔsolvH∘ an additive scheme surface applying Scaled Particle Theory. chain lengthening, branching, cyclization discussed. Perfluoroalkanes proved be inert molecules that interact weakly themselves as well alkanes.