Sedimentation ternary system

At elevated concentrations, hydrodynamic and other interactions between sedimenting molecules become important. Two sorts of sedimentation measurement, involving respectively a binary and a ternary system, then suggest themselves. First, s in binary polymer systems may depend on polymer concentration and molecular weight. Second, the sedimentation rate of colloidal particles or probe polymer molecules through a solution of a second polymer, as might occur in ternary systems, may depend on the second polymer s properties. 

N. Nemoto, T. Inoue, Y. Tsunashima, and M. Kurata. Dynamics of polymer-polymer-solvent ternary systems. 2. Diffusion and sedimentation of poly(methyl methacrylate) in semidilute solutions of polystyrene in thiophenol. Macromolecules, 18 (1985), 2516-2522. 

Influence of SDS concentration on relative volume of coacervate phase in the ternary system, and turbidity of the system is shown in Figure 11. Coacervate layer formation appears at the onset of HPMC-SDS interaction. Relative volume of coacervate phase increases with SDS addition, and reaches maximum at the end of HPMC-SDS interaction (i.e. at PSP). The relative volume of coacervate phase increases on addition of SDS due to increased hydrophilic properties of HPMC/SDS complex, as more SDS molecules are bound to HPMC, which results in better solvation of HPMC/SDS complex. At SDS concentrations larger than PSP the coacervate disappears. On increase in SDS concentration turbidity of the ternary mixtures decreases until it reaches constant value, which is the same as is turbidity of binary HPMC/NaCMC mixture (Measured turbidity of the ternary mixtures having lowest SDS concentrations is low due to fast sedimentation of coacervate during the measurement.). The decrease in turbidity is attributed to increase in HPMC/SDS complex solvation as SDS concentration in the ternary system is increased. 

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