Determination of the Flory–Huggins χ parameter, the heat of dilution, and the excess heat capacity of some alkanes in polydimethylsiloxane by gas chromatography

The change in standard chemical potential of a number of alkanes on PDMS going from dilute solution to the perfect vapor Δ Ḡ was measured by gas chromatography over a large range of temperatures. The change in standard chemical potential of the alkane going from the pure liquid to the perfect vapor Δ Ḡ was calculated from fugacity data. These data were fitted separately to three Taylor's series expansions wherein the (partial) heat capacity of vaporization is zero, constant, and linearly dependent on temperature, respectively. On the basis of statistical and physical arguments it was concluded that the partial excess functions determined by gas chromatography should be described with a temperature‐independent partial excess heat capacity.