Physicochemical measurements (inverse gas chromatography)

Voelkel, Adam

doi:10.1016/b978-0-12-820675-1.00013-7

Cited by 1 publication

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“…It is known that the transport of gases in thin polymer layers is often described using the gas permeability value P, which includes both the thermodynamic component (solubility coefficient S) and the kinetic component (diffusion coefficient D S ). Solubility S is interpreted as a parameter proportional to Henry's equilibrium constant, which means that changes in solubility should correlate with the solute retention coefficient k [6][7][8][9]. Despite the different previous histories of the samples used in chromatography and membrane measurements, different film thicknesses, and different testing procedures, chromatographic data can be used to refine the results obtained by other methods.…”

Section: Introductionmentioning

confidence: 99%

Chromatographic Method for Evaluation of Polymeric GC Stationary Phases Ageing Using the Novel Non-Cross-Linked Poly(3-(Tributoxysilyl)Tricyclononene-7) as the Model Stationary Phase

et al. 2021

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The chromatographic properties and thermal stability are investigated for the polymeric stationary phase based on the norbornene polymer. It was shown that without additional cross-linking, poly(3-(tributoxysilyl)tricyclononene-7) demonstrates properties similar to liquid chromatographic stationary phases. It was also found to be more thermally stable than previously studied trimethylsilyl- and trimethoxysilyl- derivatives. The long-term heating at 170 °C resulted in an increase of mass transfer rate between stationary and mobile phases which could be observed as a decrease of parameter C of Van Deemter equation. This effect is rather unusual, as the polymeric stationary phases tend in decrease of the layer volume and porosity while ageing. Additionally, the values of thermodynamic parameters of sorption are calculated for the polymeric stationary phase: enthalpy of sorption varied −28 to −37 kJ/mol, entropy change was −41 to −51 J/mol K. The compensation curves were plotted for the alkanes, arenes, and alcohols, and the parameters of compensation plot were calculated, demonstrating the different sorption mechanisms both for hydrocarbons and oxygen-containing compounds, and different classes of organic compounds.

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Section: Introductionmentioning

confidence: 99%