Experimental determination of the (vapor + liquid) equilibrium data of binary mixtures of fatty acids by differential scanning calorimetry

Interfacial Tension of the Lipid Membrane Formed from Phosphatidylcholine–Decanoic Acid and Phosphatidylcholine–Decylamine Systems

“…Many investigations have been reported on the effect of fatty acids on physical and chemical properties of model membranes, particularly on the phase behavior of hydrated phospholipid bilayers, using various techniques, such as differential thermal analysis (Ulkowski et al 2005 ), differential scanning calorimetry (Ohta and Hatta 2002 ; Matricarde Falleiro et al 2010 ; Inoue et al 2001 ), fluorescence spectroscopy (Borst et al 2000 ), X-ray diffraction (Kumar et al 2005 ), magnetic resonance (Heimburg et al 1990 ; Rama Krishna and Marsh 1990 ) and Fourier transform infrared spectroscopy (Inoue et al 2001 ).…”

Evaluation of a Variation of the Differential Scanning Calorimetry Technique for Measuring Boiling Points of Binary Mixtures at Subatmospheric Pressures

“…Very recently, Khoshooei et al 5 measured VLE data of binary mixtures of The temperature of 433.12 K is out of the range of adjusted parameters of the Antoine eq (Table S.1) for tridecane. In this case, the extended Antoine equation with parameters retrieved from the software Aspen Plus v. 10 5 for systems evidence that there is a relation between the way that the vapor escapes within the pinhole and the relative volatility between the compounds in the mixture. In fact, Brozena 8 pointed out that the pinhole size balances both preboiling vaporization and self-pressurization.…”

“…On the other hand, in the case of systems 7 (C9OH + C11OH) and 8 (C10OH + C12OH), inadequate DIF values were found for almost all the molar fractions investigated, which was not the case for system 1 (C12 + C13). In terms of Δ T b pure , systems 7 and 8 were 25.5 and 25.7 K, respectively, while for systems 1, 2, 4–6, 9, 11, and 12, Δ T b pure values were between 7.5 and 27.0 K. It is of note that Damaceno and Ceriani , and Cunico et al, which used this same technique with a heating rate of 25 K·min –1 and a sample size of 4–5 mg, worked with of Δ T b pure ranging from 13.0 to 24.6 K. Matricarde Falleiro et al and Akisawa Silva et al obtained boiling points of binary mixtures of fatty compounds using a manufacture pinhole of 0.25 mm on the lid. While Akisawa Silva et al kept a heating rate of 25 K·min –1 and worked with Δ T b pure between 18.3 and 22.6 K, Matricarde Falleiro et al applied two different heating rates depending on the difference between the carbon chain length of the compounds, that is, for Δ T b pure of 42.2 K they used a heating rate of 15 K·min –1 , and for Δ T b pure between 20.0 and 22.0 K they used 25 K·min –1 as the heating rate.…”

“…Usually, in the presence of preboiling vaporization, the endothermic peak presents a nonflat baseline and a reduced leading edge. , As pointed out by Khoshooei et al and Matricarde Falleiro et al, this effect may be more pronounced in the case of a binary mixture in comparison with a pure compound. The dynamic equilibrium that is present inside the crucible for a mixture leads to a continuous change in its boiling point, as the vapor phase escapes, and the liquid phase becomes heavier (less volatile).…”

“…Considering the experimental determination of boiling points (vapor pressure or vapor–liquid equilibrium data), a nontraditional technique that has been under study is the differential scanning calorimetry (DSC) technique and its variations. The main reasons that support its use are (a) it requires a very small amount of sample (4–5 mg), which is a relevant factor when dealing with high-priced compounds, (b) its short analysis time, and (c) in the case of mixtures (more recent use), it does not require other chemical analysis for direct or indirect quantification (calibration curves) of the compositions of phases in thermodynamic equilibrium. − Yet, it is capable of providing only PTx data, which is a hindrance in terms of thermodynamically consistent experimental data. Detailed information about the DSC technique itself applied for measuring vapor–liquid equilibria and/or vapor pressure of data could be obtained from selected works in the literature. ,,− , …”