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Abstract: The partitioning behavior of the [Fe(CN)5(NO)]2− and [Fe(CN)6]3− anions were studied in aqueous two-phase systems (ATPS) formed by potassium phosphate and macromolecules—poly(ethylene oxide) (1500gmol−1) and triblock copolymers, PEO–PPO–PEO, where PEO and PPO are poly(ethylene oxide) and poly(propylene oxide), respectively. Two copolymers with different hydrophobicity were used, L35 (50% EO and 1900gmol−1) and F68 (80% EO and 8400gmol−1). The partition coefficient for the [Fe(CN)5(NO)]2− and [Fe(CN)6]3− anions in each ATPS were investigated as a function of the temperature, tie-line length and phases hydrophobicity. The relative order of the partition coefficient is L35

Abstract: This work developed a new and efficient method of extracting and separating Co(II), Ni(II) and Cd(II) in aqueous two-phase systems (ATPS) composed of triblock copolymer (L64)+Na2C4H4O6 +water and L64+Li2SO4 +water using the hydrophobic extractant 1-nitroso-2-naphtol, which complexes the metal ions and partitions in the triblock copolymer micelles in the ATPS top phase. Metal extraction from the salt-rich phase to the copolymer – rich phase is strongly affected by the fine-tuning of the following parameters: amount of added extractant, type of electrolyte, pH, and tie-line length. Excellent separation factors (S i,j) between the metals were obtained at pH = 3.00 (S Co,Cd = 1550 and S Ni,Cd = 16,700) and pH = 1.00 (S Co,Ni = 826). In the interference study, Co(II) was selectivity extracted in the top phase in the presence of Ni(II) and Cd(II) in a concentration of up to 20 times the cobalt level in the system. [Copyright &y& Elsevier]

Polydiacetylene (PDA) vesicles have been applied as optical sensors in different areas, although there are difficulties in controlling their responses. In this study, we prepared nanoblends of PDA with triblock copolymers (TC) as a better sensor system for detecting temperature change. The influences of diacetylene (DA) monomer, and the TC chemical structure and concentration on the colorimetric response (CR) were examined. The TC/PDA nanoblend was remarkably more sensitive to temperature change, than classical vesicles. A higher L64 concentration of 12.0% (w/w) reduced the chromatic transition temperature (T tr ) to as low as 24 °C. When using different TCs, the T tr values can be ordered as L35 < F68< L64 < F127

Polydiacetylene (PDA) and triblock copolymer nanoblends were synthesized to detect micellar casein (MC), the main milk protein and an indicator of milk quality. UV–Vis spectrum showed that MC induced blue-to-red transition in nanoblends. When nanoblends and MC were separated by dialysis membrane colorimetric response (CR) was similar, whereas a remarkable CR reduction was noticed after addition of dialyzed-MC, suggesting that small molecules present in MC (salts) caused PDA color change. Interaction enthalpy variation between nanoblends and MC showed an abrupt increase that coincided with MC concentration when colorimetric transition occurred. Copolymer hydrophobic/hydrophilic balance and presence of other molecules in the system affected nanoblends CR. MC salts were found to interact with nanoblends leading to color changes. MC concentration, MC salt release, copolymer hydrophobic/hydrophilic balance, and presence of other molecules in the system affected responses of the sensors. These results contribute to future applications of PDA/copolymer nanosensors to dairy models. [ABSTRACT FROM AUTHOR]

Highlights: [•] A green and low cost technique for metal separation was discovered. [•] Aqueous two-phase system (ATPS) is predominantly composed by water. [•] ATPS is an efficient substitute for liquid-liquid extraction using organic solvent. [•] Excellent separation factor for Cu and Zn was obtained. [Copyright &y& Elsevier]

Abstract: The separation of Cd and Ni from Ni–Cd batteries using an aqueous two-phase system (ATPS) composed of copolymer L35, Li2SO4 and water is investigated. The extraction behavior of these metals from the bottom phase (BP) to the upper phase (UP) of the ATPS is affected by the amount of added extractant (potassium iodide), tie-line length (TLL), mass ratio between the phases of the ATPS, leaching and dilution factor of the battery samples. Maximum extraction of Cd (99.2±3.1)% and Ni (10.6±0.4)% is obtained when the batteries are leached with HCl, under the following conditions: 62.53% (w/w) TLL, concentration of KI equal to 50.00mmolkg−1, mass ratio of the phases equal to 0.5 and a dilution factor of battery samples of 35. This novel methodology is efficient to separate the metals in question, with the advantage of being environmentally safe, since water is the main constituent of the ATPS, which is prepared with recyclable and biodegradable compounds. [Copyright &y& Elsevier]

Abstract: This work aimed to study the partition of cheese whey proteins α-lactoalbumin and β-lactoglobulin using aqueous two-phase system by applying the cloud point extraction technique. The cloud point temperatures were determined under different concentrations of copolymer and salt. The system providing the best protein separation conditions was 20mass% of copolymer PE61 and potassium phosphate salt solution of 100mM, at pH 7. The protein α-lactoalbumin remained preferentially in the aqueous phase and the β-lactoglobulin was transferred to the copolymer phase. [Copyright &y& Elsevier]