The sedimentation diffusion equilibrium of a ternary gel
The well know theory of a binary gel, which is considered to be an elastic liquid mixture consisting of a crosslinked polymer component and a low molecular solvent, is extended to a ternary system, where instead of the pure solvent a polymer solution is given. The equations describing the continuous equilibria are derived for the solution and the gel phase. As soon as the gel is placed into the centrifugal field, an osmotically active pressure in the gel phase appears, which is identical to a swelling pressure. The latter can be calculated from the distribution of the solvent and the soluble uncrosslinked component in the grel phase. At higher fields a discontinuous phase boundary gel/solution will occur. In case no gel phase is present, the system reduces to a binary solution in the centrifugal field. At the phase boundary gel/solution the well known deswelling effect is expected if the soluble polymer is expelled from the network. The discussion includes the necessary experimental quantities for the determination of the thermodynamic properties of physically crosslinked gels where a soluble part is present which is not built into the network but is acting as a second solvent.
Key wordsThernary gel continuous equilibrium swelling swelling pressure centrifugal field
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- 2.Borchard W, Cölfen H (1992) Makromol Chem Makromol Symp 61:143Google Scholar
- 3.Svedberg T, Pedersen KO (1940) Die Ultrazentrifuge. Steinkopff-Verlag, DresdenGoogle Scholar
- 4.Haase R (1963) Thermodynamik der irreversiblen Prozesse. Steinkopff-Verlag, DresdenGoogle Scholar
- 5.Fujita H (1962) Mathematical Theory of Sedimentation AnalysisGoogle Scholar
- 6.Haase R (1956) Thermodynamik der Mischphasen. Springer-Verlag, Berlin-Göttingen-HeidelbergGoogle Scholar
- 8.Scholte Th G (1968)J Polym Sci (A-2) 6:91 (1970) European Polym J 6:51Google Scholar
- 10.Tompa H (1956) Polymer Solutions Butterworths Scientific Publication, LondonGoogle Scholar
- 11.Cölfen H (1993) dissertation, DuisburgGoogle Scholar