ISSUE 1

ISSUE 2

ISSUE 3

ISSUE 4

ISSUE 5

ISSUE 6

ISSUE 7

ISSUE 8

ISSUE 9

ISSUE 10

ISSUE 11

ISSUE 12

ISSUE 1

Year 2005, Month 1 (Section Full Articles, Page 141)

Inf luence of the chemical nature of siloxanes on the thermodynamic characteristics of sorption for a series of linear and cyclic saturated hydrocarbons

T. M. Roshchina and M. S. Shepeleva*

The thermodynamic characteristics of sorption (Henry´s constants of sorption equilibrium Ksorp, heats of sorption q, and standard entropies of sorption ∆S°) were studied by gas chromatography to describe the behavior of linear and cyclic saturated hydrocarbons on phenylmethylsiloxane HP-5, fluoromethylsiloxane OV-210, and methylsiloxane OV-1. The Ksorp and q values and, correspondingly, the energy of dispersion interactions decrease in the series HP-5 > OV-1 > OV-210. The difference in structures of adamantane, trans-decalin, and decane molecules has almost no effect on the heats of sorption. Henry´s constants increase on going from decane to trans-decalin and, further, to adamantane. This effect becomes more pronounced with an increase in the sorbent polarity (OV-1 < HP-5 < OV-210). The entropy factor can play a key role in sorption processes on siloxanes.

BACK   I wish to order PDF file of this article for 25.00 USD