ISSN:
1572-8927
Keywords:
Orientational order
;
torsional oscillations
;
n-alkanes
;
gas chromatography
;
thermodynamics
;
Patterson
;
Flory
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Using retention voluems, obtained from gas-liquid chromatography with then-alkanesn-C28,n-C32, andn-C36 and the branched alkane squalane (2,6,10,15,19,23-hexamethyltetracosane) as the solvents and small branched andn-alkane molecules as solutes, excess chemical potentials were determined at 80, 100, and 120°C. From these data Flory'sX 12 parameter was calculated, which is related to differences in force field and in orientatinal order of the two compounds. After correction for end effects, theX 12 parameter in then-alkane solvents appeared to decrease with rising temperature and to increase with increasing chain length of then-alkane solvent. In addition,X 12 was dependent on the shape of the order-disturbing substance. These results all point to the presence of short-range orientational order in liquidn-alkanes, which was deduced to occur before from enthalpies of mixing by Patterson and from depolarized Rayleigh scattering by Bothorel. In addition, it is shown that theX 12 values are influenced by coupling of torsional oscillations of the molecules of the mixture components.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01074866
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