Activity coefficient at infinite dilution measurements for organic solutes (polar and non-polar) in fatty compounds: Saturated fatty acids

Activity coefficient at infinite dilution measurements for organic solutes (polar and non-polar) in fatty compounds – Part II: C18 fatty acids

“…Analysing the values 13 for alkane, alkene, and cycloalkane with the same carbon number, it was found the follow hierarchy for the c 1 13 values in increasing order: cyclohexane < hex-1-ene < n-hexane. In the case of cycloalkanes, it should be considered that their molar volumes are smaller than those of linear alkane and alkene with the same number of carbons atoms, therefore the packing effect additionally increases the interaction with fatty acids, the same was observed in previous work [30] and for others solvents as ionic liquids [47][48][49]. The alkene double bond leads to stronger mutual interactions between the fatty acids and the solute hex-1-ene than between the fatty acids and n-hexane.…”

“…In terms of the overall magnitude of the c 1 13 values (maximum around 4.6 for linolenic acid), it can be noted that unlike our previous work with saturated fatty acids [30], the values of c 1 13 present more pronounced deviations from ideal mixture behaviour. For all solvents investigated, the lowest values of c 1 13 are observed for chloroform followed by other chlorine-containing compounds (trichloroethylene, chlorobenzene, and 1,2-dichloroethane) which means that independent of the presence of cis double bonds in the fatty acid chain, chloroform has a strong interaction with fatty acids (unsaturated or not), that can be result from van der Waals forces and polarity effects.…”

“…In a previous work [30], we have already noted that the combination of a rather long non-polar hydrocarbon chain and the strongly polar carboxylic acid group enables fatty acids to dissolve easily both polar and non-polar compounds. In this study we could observe the influence of the presence and number of cis double bonds in fatty acids in the interaction with several solutes.…”

“…In our previous work [30], the c 1 13 of several solutes in saturated fatty acids: capric acid (C10:0), lauric acid (C12:0), myristic acid (C14:0), and palmitic acid (C16:0) were measured and different trends for polar and non-polar solutes could be identified, both in the series of fatty acids and as function of temperature. This paper is a continuation of that work, and it discusses the role of the double bonds in the structure of the fatty acid (solvent) in the solvent-solute interaction with the aim to contribute to the pool of knowledge available to develop a greater understanding of the correlation between structure and function for the various fatty acids.…”

Measurement, correlation and prediction of isothermal vapor–liquid equilibria of different systems containing vegetable oils

“…This paper presents results of a part of our research work in field of fatty compounds and it complements the study of thermophysical properties of these components for the development of predictive thermodynamic models. In previous papers, activity coefficients at infinite dilution (g i 1 ) in saturated and unsaturated fatty acids (capric, lauric, myristic, palmitic, stearic, oleic, linoleic, and, linolenic acids) and in refined vegetable oils have already been reported [32][33][34] as well as excess enthalpies (H E ) of systems containing refined vegetable oils [35]. In this work, vapor-liquid equilibria (VLE) for mixtures of refined soybean, sunflower or rapeseed oils with methanol, ethanol or hexane have been measured at 348.15 K and 373.15 K. Additionally, the experimental VLE, g i 1 [34] and H E [35] data were simultaneously correlated using temperature-dependent interaction parameters for the g E -model UNIQUAC [36] and predicted by modified UNIFAC Dortmund (mod.…”