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The activity coefficients at infinite dilution, γ 13 ∞ , for hydrocarbons and methanol solutes in the ionic liquid 1-butyl-3-methylimidazolium octyl sulfate, [BMIM][OcOSO 3 ], have been determined by gas-liquid chromatography at temperatures of 298.15 K, 313.15 K, and 328.15 K. This work is part of our research focus on activity coefficients at infinite dilution, γ 13 ∞ , in ionic liquids. The selectivity values have been calculated at T ) 298.15 K, and the results indicate that the ionic liquid [BMIM][OcOSO 3 ] should not be considered to be a solvent for the separation of alkanes and aromatics. The partial molar excess enthalpy values at infinite dilution ∆H 1 E∞ have also been determined at temperature 298.15 K and have been discussed in terms of intermolecular interactions and packing effects. The results have been discussed in terms of measurements of γ 13∞ for other ionic liquids taken from the recent literature.

Solid + liquid) and (liquid + liquid) phase diagrams have been determined for (1-octanol, 1-nonanol, 1-decanol, or 1-undecanol + acetonitrile, propanenitrile, or butanenitrile) mixtures. Only mixtures with acetonitrile show immiscibility in the liquid phase with an upper critical solution temperature. The excess molar volumes (V m E ) have been determined for a 1-alkanol (1-octanol, 1-nonanol, 1-decanol, or 1-undecanol + propanenitrile) and (1-undecanol + butanenitrile) at 298.15 K and atmospheric pressure. For all the mixtures investigated in this work, the V m E is small and positive. Mixtures were investigated in terms of the modified UNIFAC (MU) model using the interaction parameters cited in the literature. The model describes in the correct range of temperature and composition the liquidus curves, critical points, and excess molar enthalpies. The Extended Real Associated Solution (ERAS) and Flory-Benson-Treszczanowicz (FBT) models were also used to represent the V m E data and to predict excess molar enthalpies of the investigated systems. Excess molar volumes and enthalpies (literature data) are wellrepresented by the ERAS model. The ERAS model gives the better prediction than that of the MU model for excess molar enthalpies. The calculated curves using ERAS are closer to the experimental points except in the region of low concentration in alcohol. This means that, in terms of ERAS, the contribution to the excess molar enthalpy from the self-association of the alcohol is overestimated. The MU model underestimates the excess molar enthalpy. The FBT model cannot be used to predict these data as the interaction of the unlike molecules is not described in this model.

Electrochemical aided abrasive flow machining (ECAFM) is possible using polymeric electrolytes. The ion conductivity of electrolytes is many times lower than the conductivity of electrolytes employed in ordinary electrochemical machining (ECM). Additions of inorganic fillers to electrolytes in the form of abrasives decrease conductivity even more. These considerations explain why the interelectrode gap through which the polymeric electrolyte is forced should be small. This in turn results in greater flow resistance of polymeric electrolyte, which takes the form of a semi-liquid paste. Rheological properties are also important for performance considerations. Experimental investigations have been carried out for smoothing flat surfaces and process productivity in which polymer electrolytes as gelated polymers and water-gels based on acryloamide were used.

Solid + liquid phase diagrams have been determined for 1-octanol, 1-nonanol, 1-decanol, or 1-undecanol + decylamine mixtures. Solid addition compounds form with the empirical All are congruently melting compounds. Compound formation is attributed to a strong A-B interaction. The excess molar volumes, V m E , have been determined for these mixtures at 298.15 K and atmospheric pressure. The systems exhibit very large negative excess molar volumes, V m E , and excess molar enthalpies, H m E . The V m E curves are nearly symmetrical. Strong crossassociation between hydroxyl and amine groups (OH‚‚‚NH 2 ) is a dominant effect, and it causes high negative values of V m E and H m E and 1:1 congruently melting solid compounds at lower temperatures. Our experimental data on V m E and the literature data on H m E were treated in terms of the ERAS model, DISQUAC, and modified UNIFAC. The ERAS model consistently describes V m E and H m E of the studied mixtures. IntroductionIn this series of papers, 1,2 our general aim is to confirm, from solid + liquid equilibrium (SLE) measurements, the interactions between unlike molecules in systems that exhibit very strong negative deviations from Raoult's law. Mixtures of alcohols and amines show large negative values of excess molar volumes, V m E , and excess molar enthalpies, H m E . Strong intermolecular interactions between the hydroxyl group and the amine group lead to the largest negative values found for organic mixtures in the literature, as was very well described by the extended real associated solution model, ERAS. 3-9 A new systematic characterization, using different models of interactions between unlike molecules and new experimental data on excess molar volumes, was shown for n-alkane + triethylamine or tributylamine 10 and alkanols + dipropylamine 11 or methylbutylamine 12 systems. In the systems under study, the strong intermolecular hydrogen bonds O-H‚ ‚‚N predominate over the O-H‚‚‚O and N-H‚‚‚N bonds. Thus, mixtures of long-chain 1-alcohols and long-chain amines also comprise an interesting class of systems that exhibit very strong negative deviations from Raoult's law. In fact, such systems show extremely negative excess molar volumes, V m E , and enthalpies, H m E , which are confirmed by the congruently melting compounds in the solid state at much lower temperatures. The disruption of semi-association between A-A and B-B molecules upon mixing leads to a positive contribution to V m E and H m E . Strong intermolecular A-B interactions contribute negatively to V m E and H m E . Generally, amines (primary, secondary, tertiary, or aromatic) are good proton acceptors, and the values of A-B cross-hydrogenbonding energies of between -32 and -45 kJ‚mol -1

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