Electrostatic and electrokinetic potentials in two polymer aqueous phase systems

Brooks, Donald E.; Sharp, Kim A.; Bamberger, Stephan; Tamblyn, Cherry H.; Seaman, G. V. F.; Walter, Harry

doi:10.1016/0021-9797(84)90195-4

Cited by 88 publications

(60 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The potentials measured are in the range 0-7 mV. Previous studies (Reitherman, 1973;Johansson, 1973;Brooks et al, 1984;Sharp, 1987) have also reported values in this range, although for phase systems with different polymer molecular weights and salt concentrations. As expected, extrapolation of these plots result in zero potential difference (within experimental error = 0.1 mV) at a tie-line length of zero (a homogeneous solution).…”

Section: Resultsmentioning

confidence: 67%

See 1 more Smart Citation

Molecular thermodynamics of aqueous two‐phase systems for bioseparations

1988

View full text Add to dashboard Cite

Aqueous polymer-polymer two-phase systems provide a powerful method for separating biomolecules by extraction. When a complex mixture of biomolecules (e.g., a fermentation broth or a solution of lysed cells) is added to such a system, biomolecules partition uniquely between the two phases, achieving separation.A thermodynamic framework is presented for optimizing extraction performance in biological separations. First, a rnolecular-thermodynamic model, based on the osmotic virial equation, is proposed to describe phase equilibria for dilute aqueous mixtures containing polymers and protein. Second, experimental phase-equilibrium data (protein partition coefficients) are reported for a number of model proteins including albumin, lysozyme, and a-chymotrypsin. To interpret and correlate the experimental data, Low-Angle Laser-Light Scattering (LALLS) measurements were made to determine osmotic second virial coefficients for aqueous mixtures containing polymers, proteins, salts (KCI, KH,PO, and K,S04 at concentrations of 50 and 100 mM) and several combinations of polymer-polymer and polymer-protein pairs. Combined with electrochemical measurements (differences in potential between the two phases and protein net charge), these data provide parameters for the model to calculate the desired phase equilibria. A comparison of calculated and experimental results indicates that the virial-equation model provides good prediction of binodals and a reliable basis for estimating infinite-dilution protein partition coefficients for biotechnical process design.

show abstract

Section: Resultsmentioning

confidence: 67%

“…Figure 1 shows a schematic of the microelectrode apparatus used to measure an electric potential difference between the two aqueous phases. The protocol followed is the same as that of Brooks et al (1984) and Sharp (1987).…”

Section: Partition-coefficient Measurementsmentioning

confidence: 99%

Molecular thermodynamics of aqueous two‐phase systems for bioseparations

1988

View full text Add to dashboard Cite

show abstract

“…Most of these previous modeling efforts have focused on a description of nonelectrostatic forces, in particular excluded-volume forces, affecting phase diagrams and partition coefficients. For example, an 1974a; Reitherman et al, 1973;Bamberger et al, 1984;Brooks et al, 1984;Sharp et al, 1986;Zaslavsky et al, 1978Zaslavsky et al, -1983Zaslavsky et al, , 1986Zaslavsky et al, -1988Zaslavsky et al, , 1991. For realistic engineering applications, it is essential that electrostatic forces be included in any model for aqueous solutions containing proteins.…”

Section: Spainmentioning

confidence: 98%

“…However, salts which partition unevenly between the phases of such systems are known to create interfacial electrostatic-potential differences Bamberger et al, 1984;Sharp et …”

Section: Salt Partition Coefficients In Polymer-polymer Aqueous Two-pmentioning

confidence: 99%

Application of integral‐equation theory to aqueous two‐phase partitioning systems

et al. 1993

View full text Add to dashboard Cite

“…Some inorganic salts are more able to promote this effect (e.g., CaCl 2 , MgCl 2 , AlCl 3 ) when the ions form association complexes with the ether groups. 7 The effects of polymer molar mass, concentration, phase density and the presence of salts in aqueous two-phase polymeric systems have been studied by many authors: Albertsson 6,[18][19][20][26][27][28][29][30][31]41 The partitioning coefficient of proteins and biomolecules in conventional aqueous two-phase polymeric systems is not extreme. In order to enhance partitioning it is possible to add to the system affinity ligands.…”

Section: Aqueous Two-phase Polymeric Systems -Atppsmentioning

confidence: 99%

Liquid–liquid extraction of biomolecules: an overview and update of the main techniques

Mazzola

Lopes

Hasmann

et al. 2007

J of Chemical Tech & Biotech

220

119

View full text Add to dashboard Cite

Two-phase systems can be exploited in separation science for the extraction/purification of desired biomolecules. This article reviews recent experimental work on the use of aqueous two-phase polymer systems, two-phase aqueous micellar systems and reversed micellar systems for the extraction/purification of biomolecules. The experimental partitioning behavior of different biomolecules is reviewed and new results with nisin and lipopolysaccharides are presented. An extensive description of each system is presented, based on the biomolecules behavior and the tools employed to improve their extraction and purification.

show abstract

Electrostatic and electrokinetic potentials in two polymer aqueous phase systems

Cited by 88 publications

References 15 publications

Molecular thermodynamics of aqueous two‐phase systems for bioseparations

Molecular thermodynamics of aqueous two‐phase systems for bioseparations

Application of integral‐equation theory to aqueous two‐phase partitioning systems

Liquid–liquid extraction of biomolecules: an overview and update of the main techniques

Contact Info

Product

Resources

About