Influence of the molecular weight of polymer, temperature and pH on phase diagrams of poly (ethylene glycol) + di-potassium tartrate aqueous two-phase systems

Barani, Alireza; Pirdashti, Mohsen; Heidari, Zahra; Drăgoi, Elena Niculina

doi:10.1016/j.fluid.2017.11.037

Cited by 30 publications

(25 citation statements)

References 52 publications

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“…2), it can be observed that PEG 4000 (of higher molar mass) presented a larger two-phase region. A similar behavior was observed by Barani et al (2018) in the conventional ATPS formed by PEG (1500 or 6000) and salt (di-potassium tartrate). Rodríguez et al (2009) found that polymers with higher molecular weights are less soluble in ionic liquid and are more easily separated from the aqueous medium, due to decreased PEG solubility in water with increased polymer molar mass.…”

Section: Phase Diagramssupporting

confidence: 78%

“…ATPS are formed by two phases coexisting in equilibrium due to the dissolution, at appropriate concentrations, of solute pairs in water (Freire et al 2012;Wu et al 2017). They are formed by two immiscible or partially miscible aqueous phases which can be obtained by the addition of two aqueous solutions of two natural or synthetic hydrophilic polymers, of a polymer solution and a saline solution, an ionic liquid and a salt or polymer, a surfactant and polymer or salt or a low molecular weight alcohol and a salt (Rodríguez et al 2009;Pereira et al 2013;Liu et al 2015;Hekayati et al 2016;Fan et al 2017; Barani et al 2018;Junqueira et al 2018;Oliveira et al 2018;Escudelo et al 2019;Penido et al 2019).…”

Section: Introductionmentioning

confidence: 99%

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Aqueous two-phase system (polyethylene glycol + ionic liquid) for extraction of α-amylase: phase diagrams, systems characterization and partition study

Gandolfi

Gonçalves

Batista

et al. 2020

Braz. J. Chem. Eng.

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The increasing demand for safe and effective methods for the separation of biological materials combining the advantageous properties of polyethylene glycol (PEG) (1500 g mol −1 or 4000 g mol −1) and ionic liquid has led to attractive and promising applications of the new aqueous biphasic systems. In this work, the liquid-liquid extraction process with aqueous two-phase systems (ATPS) was studied for α-amylase partitioning. The phase diagrams composed of PEG (1500 or 4000) g mol −1 + 1-ethyl-3-methylimidazolium chloride + water, were determined experimentally by the turbidimetric method at different temperatures T = (293.15, 303.15, 313.15 and 323.15) K. The effect of temperature and polymer molar mass on the phase diagrams, as well as the phase densities, refractive indexes and electrical conductivity were evaluated. Subsequently, the α-amylase partitioning was performed, where the partition coefficient was determined, besides the activity and selectivity. It was found that a temperature decrease and a polymer molar mass increase favored the formation of two phases. It was also found that α-amylase showed a preference for the bottom phase composed of PEG and the systems composed of PEG 1500 presented better results. Keyword Liquid-liquid extraction • Enzyme • Partition • Amylase Abbreviations ATPS Aqueous two-phase systems PEG Polyethylene glycol [C 2 min]Cl 1-Ethyl-3-methylimidazolium chloride TLL Tie-line lengths STL Tie-line slope U One enzyme activity unit releases 1 mmol of reducing sugar per mL of extract per minute, U mL −1 ART Total reducing sugars produced in the hydrolysis step, mg mL −1 VT Total volume used in the hydrolysis, mL V c Volume of sample used in the hydrolysis, mL R t Reaction time, min BSA Bovine serum albumin K p Protein partition coefficient C t Equilibrium concentration of the total protein in the top, mg mL −1 C b Equilibrium concentration of the total protein in the bottom, mg mL −1 K e Partition coefficient for enzyme activity A t Enzyme activity in the top, mg mL −1 A b Enzyme activity in the bottom, mg mL −1 Δ tr G Gibbs free energy variation, kJ mol −1 T Absolute temperature, K R Ideal gas constant, kJ mol −1 K −1

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Section: Phase Diagramssupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Aqueous two-phase system (polyethylene glycol + ionic liquid) for extraction of α-amylase: phase diagrams, systems characterization and partition study

Gandolfi

Gonçalves

Batista

et al. 2020

Braz. J. Chem. Eng.

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“…It is important to note that temperature control is essential during the whole experimental procedure. The experimental procedure has been described in detail in previous studies, ,− and all devices used in this study were essentially the same as in our previous work . Stock solutions of PEGs (50 and 80 wt %), zinc sulfate (30 wt %), and ammonium sulfate (40 wt %) were prepared.…”

Section: Experimental Evaluationmentioning

confidence: 99%

Phase Equilibria of Aqueous Two-Phase Systems of PEG with Sulfate Salt: Effects of pH, Temperature, Type of Cation, and Polymer Molecular Weight

et al. 2021

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The present work reports the liquid–liquid equilibrium (LLE) measurements and the construction of binodal curves for polyethylene glycols (PEG) + zinc sulfate/ammonium sulfate + water at three different temperatures (298.15, 303.15, and 308.15 K) and pH values (3.00, 4.70, and 5.21). PEGs with different molecular weights of 2000 g·mol–1 (PEG 2000), 3000 g·mol–1 (PEG 3000), and 8000 g·mol–1 (PEG 8000) were chosen for this study. The phase composition was obtained by measuring the refractive index (n D) and density (ρ) and was further used to obtain the tie-line length (TLL) and the slope of tie-line (STL). The tie-lines are reported at different polymer lengths, pH values, and temperatures. The values of the effective excluded volume (EEV) were employed to analyze the effect of the parameters on the binodal curves. Moreover, the impact of those parameters on the TLL and STL and plait point are discussed and compared with the results of the literature. Furthermore, the binodal curves data and the tie-lines’ ends were fitted using some semiempirical equations with satisfactory results. Finally, the UNIFAC is used to calculate the LLE data of the above system and the adjusted binary group interaction parameters of the model were reported.

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“…Different electrolytes have been used in the literature to obtain ATPS composed of macromolecules, such as sulfates, 17−21 phosphates, 22,23 citrates, 24,25 thiocyanates, 26 and tartrates. 23,25,27,28 However, as far as we know, liquid−liquid equilibrium data made up of ammonium thiosulfate are not related in the literature. Two studies reporting the use of sodium thiosulfate to obtain ATPS with PEO with a molar mass of 1500, 4000, or 6000 g mol −1 .…”

Section: Introductionmentioning

confidence: 99%

“…The acquisition of liquid–liquid equilibrium data for new green ATPS with greater hydrophobicity, investigating the effect of the hydrophobic/hydrophilic balance of the macromolecule on the formation of the systems, can assist in elucidating the mechanisms that lead to their formation to expand the potential applications in the field of separation/purification. Different electrolytes have been used in the literature to obtain ATPS composed of macromolecules, such as sulfates, − phosphates, , citrates, , thiocyanates, and tartrates. ,,, However, as far as we know, liquid–liquid equilibrium data made up of ammonium thiosulfate are not related in the literature. Two studies reporting the use of sodium thiosulfate to obtain ATPS with PEO with a molar mass of 1500, 4000, or 6000 g mol –1 . , The use of ammonium thiosulfate ((NH 4 ) 2 S 2 O 3 ) as the electrolyte is an excellent strategy for the separation of analytes, mainly metal ions, because, compared to many other salts, it is inexpensive and nontoxic and has reducing and complexing characteristics.…”

Section: Introductionmentioning

confidence: 99%

Liquid–Liquid Equilibrium Data of Macromolecule + Ammonium Thiosulfate + Water Ternary Systems at 283.2, 298.2, and 313.2 K

et al. 2021

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Liquid−liquid equilibrium data were obtained for aqueous two-phase system (ATPS) composed of [poly(ethylene oxide) (PEO1500), poly(propylene oxide) (PPO425), poly(ethylene oxide) 11 −poly(propylene oxide) 17 −poly(ethylene oxide) 11 (L35), or poly(propylene oxide) 8 −poly(ethylene oxide) 22 −poly(propylene oxide) 8 (10R5)] + ammonium thiosulfate + water, at 283.2, 298.2, and 313.2 K. The consistencies of the all tie-line experimental compositions were improved by applying the Othmer− Tobias and Bancroft equations, resulting in linear correlation coefficients (R 2 ) ≥ 0.95. For all the ATPS, an increase in the temperature resulted in increases in the biphasic region and the tie-line slope, indicating that the phase separation process was entropically driven. Among the macromolecules studied, PPO425 produced the largest biphasic region, due to its greater hydrophobicity, followed by L35 ≈ 10R5 > PEO1500.

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Influence of the molecular weight of polymer, temperature and pH on phase diagrams of poly (ethylene glycol) + di-potassium tartrate aqueous two-phase systems

Cited by 30 publications

References 52 publications

Aqueous two-phase system (polyethylene glycol + ionic liquid) for extraction of α-amylase: phase diagrams, systems characterization and partition study

Aqueous two-phase system (polyethylene glycol + ionic liquid) for extraction of α-amylase: phase diagrams, systems characterization and partition study

Phase Equilibria of Aqueous Two-Phase Systems of PEG with Sulfate Salt: Effects of pH, Temperature, Type of Cation, and Polymer Molecular Weight

Liquid–Liquid Equilibrium Data of Macromolecule + Ammonium Thiosulfate + Water Ternary Systems at 283.2, 298.2, and 313.2 K

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