Water: The Third Component in Polymer Two-Phase Systems
Phase systems which are close to the critical point can be changed from biphase to monophase by increasing temperature or adding urea or water. Lower temperature or tert. Butanol have the opposite effect. These observations imply that water structure plays an important part in phase separation. Flow calorimetry of dextran and PEG solutions shows that these polymers are strongly solvated and that solute: solvent: solvent interactions are predominant in these systems. In mixing experiments the critical point appears thermochemically trivial and it is suggested that like polymer hydates form micro-phases at concentrations below the critical point.
KeywordsWater Structure Guanidine Thiocyanate Polymer Hydrate Flow Calorimetry Lower Molecular Weight PEGs
Unable to display preview. Download preview PDF.
- 1.D.E. Brooks, K.A. Sharp and D. Fisher. Theoretical aspects of partitioning, in: “Partitioning in Aqueous Two-Phase Systems,” H. Walter, D.E. Brooks and D. Fisher, eds., Academic Press, London (1985)Google Scholar
- 2.A Sjöberg, H. Wennerstrom, F. Tjerneld, Microorganisms in aqueous two-phase systems, in: “Microbial Physiology for Biotechnological Innovation,” IVA Rapport 330, Swedish Academy of Engineering Sciences, Stockholm (1987)Google Scholar
- 3.P.J. Cheek, K.G. Davis and T.H. Lilley, J. Chem. Soc. Faraday Trans. in pressGoogle Scholar
- 4.T. Treffry and B. Sheth, in: “Separations Using Aqueous Phase Systems: Applications in Cell Biology and Biotechnology,” D. Fisher and I.A. Sutherland, eds., Plenum, New York (1989)Google Scholar
- 5.S.H. Gaffney, E. Haslam, T.H. Lilley and T.R. Ward, Homotactic and heterotactic interactions in aqueous solutions containing some saccharides. Experimental results and an empirical relationship between saccharide solvation and solute-solute interactions, J. Chem. Soc. Faraday Trans. 1:84 (1988), in pressGoogle Scholar
- 6.G.M. Blackburn, T.H. Lilley and E.W. Walmsley, J. Chem. Soc. Faraday Trans. 76:915 (1980)Google Scholar
- 7.D.A. Cesaro, in: “Thermodynamics for Biochemistry and Biotechnology,” H.J. Hiaz, ed., Springer Verlag, Berlin (1986)Google Scholar
- 8.S.H. Gaffney, E. Haslam, T.H. Lilley and T.R. Ward, Abs. L604, 8th Int. Symp. on Solute-Solute-Solvent Interactions, Regensburg (1987)Google Scholar
- 9.T.H. Lilley, Chapter 1, in: “Biochemical Thermodynamics,” M.N. Jones, ed., Elsevier (1987)Google Scholar
- 10.P. Molyneux, “Water Soluble Synthetic Polymers: Properties and Behaviour,” CRC Press, Boca Raton (1981)Google Scholar
- 11.D.W. Davidson, Clathrate hydrates, in: “Water: a Comprehensive Treatise,” F. Franks, ed., Plenum, New York & London (1973)Google Scholar
- 12.G. Johansson, unpublished observations after presentation of this paperGoogle Scholar