Estimate of the Vapor Pressure of Squalane at Approximately 293 K Using a Knudsen Cell Method

Abstract

I report the vapor pressure of squalane hydrocarbon (2,6,10,15,19,23-hexamethyltetracosane, C 30 H 62 ) estimated from a statistical analysis of multiple weight loss measurements of Knudsen cells with orifice diameters of 4 and 8 mm exposed in vacuum for aggregated durations 5400 and 2400 h, respectively, at 293.61 ± 1.47 K. The estimated vapor pressure p v = (4.15 ± 0.17) × 10 −6 Pa is more than a factor of 6 larger than the value of ∼6.5 × 10 −7 Pa derived from estimates reported in the literature. Plausible systematic errors cannot account for this discrepancy, which suggests that the vapor pressure of squalane at temperatures near 293.61 K may be substantially higher than previously estimated. Empirical equations for the vapor pressure of squalane are proposed for the temperature range 293.61 K ≤ T ≤ 795.9 K.

Comparison of CP-PC-SAFT and PC-SAFT with k12 = 0 and PPR78 in Predicting Binary Systems of Hydrocarbons with Squalane, n-dodecylbenzene, cis-decalin, Tetralin, and Naphthalene at High Pressures

“…This inaccuracy is less pronounced for cis -decalin, tetralin, and naphthalene and more in the cases of n -dodecylbenzene and squalane, whose vapor pressures are very low. Remarkably, the available data of the latter compounds were recently put under question . Inaccuracy in predicting vapor pressures at low temperatures is a well-known drawback of CP-PC-SAFT because its parametrization does not consider these data.…”

Estimation of Fuel Properties for the Heavy Fraction of Biomass Pyrolysis Oil Consisting of Proposed Structures for Pyrolytic Lignin and Humins

“…Among all others, the heat of vaporization may be the most difficult to measure experimentally. Examples of high-quality experimental work to measure H VAP using Knudsen effusion cells can be found in Gourdin for squalane and Suuberg and Oja for primary coal tars [85,86]. However, the correlations given in Equations ( 7)-( 10) may provide reliable empirical estimates if there is a high degree of confidence in T B and some level of chemical intuition about the polarity/non-polarity of the molecule.…”

Slippery or sticky nano‐porous silica coatings impregnated with squalane: The role of oil over‐layer

“…Squalane (99%) and hexane (95.0%, anhydrous), used for the preparation of different concentrations of the impregnation oil solutions, were purchased from Sigma‐Aldrich. Squalane was selected because it has a very low vapour pressure (4 × 10 −6 Pa at 20°C) 31 and is therefore practically non‐volatile at room temperature. For comparison, the vapour pressure of hexane provided by the supplier is 1.8 × 10 7 Pa at 20°C (132 mmHg), that is, more than 12 orders of magnitude higher than that of squalane.…”