Phase equilibrium in aqueous two-phase systems containing ethylene oxide–propylene oxide block copolymers and dextran

Tada, Eduardo dos Santos; Loh, Watson; Pessôa-Filho, Pedro de Alcântara

doi:10.1016/j.fluid.2004.01.001

Cited by 22 publications

(15 citation statements)

References 19 publications

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“…A possible cause for this STL change is the transfer of water from the upper to the lower phase, increasing the polymer concentration at the top phase and decreasing the salt concentration at the bottom phase. A small variation in STL, at different temperatures, was also observed for F68 + dextran T500 systems 4 Tie Line Slope Values for L35 + Phosphate Systems at 283.15 K, 298.15 K and 313.15 K L35tie line283.15 K298.15 K313.15 K 1 2.06 2.76 3.35 2 1.66 2.10 3.36 3 1.65 2.36 3.02 4 1.68 2.49 2.37 …”

Section: Resultsmentioning

confidence: 64%

Equilibrium Phase Behavior of Triblock Copolymer + Salt + Water Two-Phase Systems at Different Temperatures and pH

Silva

Mesquita

et al. 2005

J. Chem. Eng. Data

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Data on phase equilibrium of aqueous two-phase systems formed by mixture of triblock copolymer, potassium phosphate, and water were measured as a function of three temperatures (283.15 K, 298.15 K, and 313.15 K), two pH values (7 and 12), and two copolymer molar masses (L35 of 1900 g mol -1 and F68 of 8400 g mol -1 ). The effect of the temperature was more pronounced on the behavior of the ATPS formed by the L35 copolymer as compared with that induced by the F68 copolymer. Temperature variation affected more intensively the tie line slope than the binodal position. The pH increase shifted the binodal curve to higher copolymer and phosphate concentrations corresponding to a decrease in the region of two-phase coexistence. The effect of the molar masses on the behavior of the phase diagrams for both copolymers was offset by the effects associated with the hydrophobicity of the macromolecules.

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Section: Resultsmentioning

confidence: 64%

Equilibrium Phase Behavior of Triblock Copolymer + Salt + Water Two-Phase Systems at Different Temperatures and pH

Silva

Mesquita

et al. 2005

J. Chem. Eng. Data

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“…The incompatibility between EOPOEO and polysaccharides (e.g. dextran) can lead to the formation of ATPS (Svensson, Berggren, Veide, & Tjerneld, 1999;Tada, Loh, & Pessôa-Filho, 2004), that is to say, EOPOEO and polysaccharides would enrich in the opposite phases. As for the EOPOEO-salt ATPS, with increasing salt concentration, the polymer concentration in the top phase and the salt concentration in the bottom would increase (Haraguchi, Mohamed, & Loh, 2004).…”

Section: Effect Of Salt Concentrationmentioning

confidence: 99%

Integrated method of thermosensitive triblock copolymer–salt aqueous two phase extraction and dialysis membrane separation for purification of lycium barbarum polysaccharide

Wang

Han

et al. 2016

Food Chemistry

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“…Generally, based on literature data, the uneven solute partitioning will increase with increasing tie-line length. 22 In very recently published papers, 10,15 we reported that in ATPS without any added extractant there occurs a preferential transfer of the anion [Fe(CN) 5 NO] 2from the salt-rich phase to the polymer-rich phase. In these investigations, we used ATPS formed with mixtures of aqueous solutions of PEO (MM ) 3350 and 35 000 g mol -1 ) 15 or triblock copolymers (L35 ) 1900 g mol -1 and F68 ) 8400 g mol -1 ) 23 with aqueous solutions of sulfate or phosphate salts (Li 2 SO 4 , Na 2 SO 4 , MgSO 4 , Na 3 PO 4 ).…”

Section: Resultsmentioning

confidence: 97%

PEO−[M(CN)₅NO]^x- (M = Fe, Mn, or Cr) Interaction as a Driving Force in the Partitioning of the Pentacyanonitrosylmetallate Anion in ATPS: Strong Effect of the Central Atom

Silva

Francisco

et al. 2008

J. Phys. Chem. B

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The partitioning behavior of pentacyanonitrosilmetallate complexes[Fe(CN) 5 NO] (2-), [Mn(CN) 5 NO] 3(-), and [Cr(CN) 5 NO] 3(-)has been studied in aqueous two-phase systems (ATPS) formed by adding poly(ethylene oxide) (PEO; 4000 g mol (-1)) to an aqueous salt solution (Li2 SO4, Na2 SO4, CuSO4, or ZnSO4). The complexes partition coefficients ( K complex) in each of these ATPS have been determined as a function of increasing tie-line length (TLL) and temperature. Unlike the partition behavior of most ions, [Fe(CN) 5 NO] 2(-) and [Mn(CN) 5 NO] 3(-) anions are concentrated in the polymer-rich phase with K values depending on the nature of the central atom as follows: K [Fe(C N) 5 NO] 2 - >> K [ Mn (CN 5 NO] 3 - > K [C r (C N) 5 NO ]3 - . The effect of ATPS salts in the complex partitioning behavior has also been verified following the order Li2 SO 4 > Na2 SO 4 > ZnSO4. Thermodynamic analysis revealed that the presence of anions in the polymer-rich phase is caused by an EO-[M(CN) 5 NO] ( x- ) (M = Fe, Mn, or Cr) enthalpic interaction. However, when this enthalpic interaction is weak, as in the case of the [Cr(CN) 5 NO]3(-) anion ( K [Cr(CN 5 NO] 3 - < 1), entropic driving forces dominate the transfer process, then causing the anions to concentrate in the salt-rich phase.

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Phase equilibrium in aqueous two-phase systems containing ethylene oxide–propylene oxide block copolymers and dextran

Cited by 22 publications

References 19 publications

Equilibrium Phase Behavior of Triblock Copolymer + Salt + Water Two-Phase Systems at Different Temperatures and pH

Equilibrium Phase Behavior of Triblock Copolymer + Salt + Water Two-Phase Systems at Different Temperatures and pH

Integrated method of thermosensitive triblock copolymer–salt aqueous two phase extraction and dialysis membrane separation for purification of lycium barbarum polysaccharide

PEO−[M(CN)₅NO]^x- (M = Fe, Mn, or Cr) Interaction as a Driving Force in the Partitioning of the Pentacyanonitrosylmetallate Anion in ATPS: Strong Effect of the Central Atom

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Phase equilibrium in aqueous two-phase systems containing ethylene oxide–propylene oxide block copolymers and dextran

Cited by 22 publications

References 19 publications

Equilibrium Phase Behavior of Triblock Copolymer + Salt + Water Two-Phase Systems at Different Temperatures and pH

Equilibrium Phase Behavior of Triblock Copolymer + Salt + Water Two-Phase Systems at Different Temperatures and pH

Integrated method of thermosensitive triblock copolymer–salt aqueous two phase extraction and dialysis membrane separation for purification of lycium barbarum polysaccharide

PEO−[M(CN)5NO]x- (M = Fe, Mn, or Cr) Interaction as a Driving Force in the Partitioning of the Pentacyanonitrosylmetallate Anion in ATPS: Strong Effect of the Central Atom

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PEO−[M(CN)₅NO]^x- (M = Fe, Mn, or Cr) Interaction as a Driving Force in the Partitioning of the Pentacyanonitrosylmetallate Anion in ATPS: Strong Effect of the Central Atom