Excess molar enthalpies and volumes of binary mixtures of nonafluorobutylmethylether with ethylene glycol ethers at TÂ =Â 298.15Â K

Excess molar enthalpies, HmE and volumes, VmE were reported for binary mixtures of {nonafluorobutylmethylether, (NFBME, C4F9-O-CH3)} + [five ethylene glycol ethers, EGEn,m-R, {CmH2m + 1-(OCH2CH2)n-R, n = 1 and 2, m = 1 to 4, R = OH and OCH3}] at 298.15 K. Results of excess molar enthalpies and volumes were positive over whole range of concentrations for all the mixtures. The magnitude was in order: EGE1,4-OH > EGE1,3-OH > EGE1,2-OH > EGE1,1-OH > EGE2,1-OH > EGE2,1-OCH3 for HmE and EGE2,1-OCH3 > EGE1,4-OH > EGE1,3-OH > EGE1,2-OH > EGE1,1-OH > EGE2,1-OH for VmE at the maximum point. The curves of HmE and VmE for the EGE2,1-OH system were depressed in the middle mole fraction of NFBME, x1 suggesting a quasi-stable state in the solution. We observed occurrences of the stable emulsification state in solutions in concentrations range of 0.35 < x1 < 0.55. From these results, excess partial molar enthalpies, Hm,2E,∞, and volumes, Vm,2E,∞, of EGEn,m-R at infinite dilution, apparent molar enthalpies of solvation, ΔsolvH2, of the EGEn,m-R in NFBME were evaluated. The dependence of these thermodynamic quantities on the number of carbon atoms in the alkyl group, m, the number of the ethylene oxide group, n, and the difference of R group were discussed in consideration of various kinds of intermolecular interactions in pure component liquids and solutions.