19 documents found, page 1 of 2
Unveiling the use of hydrophobic eutectic solutions as task-specific solvents t...
Kholany, Mariam; Schaeffer, Nicolas; Macário, Inês P. E.; Veloso, Telma; Caetano, Tânia; Pereira, Joana L.; Dias, Ana C. R. V.; Coutinho, João A. P.Haloarchaea make up a class of untapped marine microbial resources that constitute a promising source of valuable compounds with unique characteristics. Bacterioruberin is a C50 carotenoid produced by haloarchaea that possesses interesting antioxidant properties and bioactivities relevant to the food and cosmetic industries. As a substitute for the conventional organic solvents used in the extraction of nonpola...
Simple gold recovery from e-waste leachate by selective precipitation using a q...
Nogueira, André F.M.; Carreira, Ana R.F.; Vargas, Sílvia J.R.; Passos, Helena; Schaeffer, Nicolas; Coutinho, João A.P.Precipitation processes, if selective, present a simple and economical alternative for the recovery of critical metals from primary and secondary ores including electronic wastes. In this work, the recovery of gold by precipitation from both mono-elemental solutions and real CPU leach solution was demonstrated using hydrophilic quaternary ammonium salts. The gold precipitation yield is shown to be dependent on ...
Tuning the ionic character of sodium dodecyl sulphate via counter-ion binding: ...
Perez-Sanchez, German; Schaeffer, Nicolas; Greaves, Tamar L.; Pereira, Jorge F. B.; Coutinho, João A. P.Solutions of surfactants exhibit remarkable features, such as a tunable amphiphilic character, which can further be varied for ionic surfactants through variations in their Coulombic interactions. These properties are very useful in many industrial applications such as in extraction, purification, and formulation processes, as detergents, wetting agents, or emulsifiers. Rather unexpectedly, the addition of tetr...
Factors driving metal partition in ionic liquid-based acidic aqueous biphasic s...
Carreira, Ana R.F.; Passos, Helena; Schaeffer, Nicolas; Svecova, Lenka; Papaiconomou, Nicolas; Billard, Isabelle; Coutinho, João A.P.The factors influencing metal partition in acidic aqueous biphasic systems (AcABS) containing phosphonium-based ILs are still poorly explored. To assess their influence the effect of the IL counter anion, acid and its concentration, and temperature, were systematically evaluated on the extraction of four transition metals (Cu(II), Co(II), Ni(II), and Mn(II)) and the lanthanide Ce(IV). The AcABS based on HCl sho...
Selective sequential recovery of zinc and copper from acid mine drainage
Passos, Helena; Cruz, Brayan; Schaeffer, Nicolas; Patinha, Carla; Silva, Eduardo Ferreira da; Coutinho, João A. P.The observed imbalance between the unsustainable consumption of available natural metal resources and finite deposits makes the recovery and recycling of metals from metal-containing wastes an imperative. Here, ionic-liquid-based aqueous biphasic systems (IL-based ABSs) are proposed as an efficient alternative for selective metal recovery from real copper acid mine drainage (AMD) effluents. ABSs composed of dif...
Synthesis of purine-based ionic liquids and their applications
Carreira, Ana R. F.; Veloso, Telma; Schaeffer, Nicolas; Pereira, Joana L.; Ventura, Sónia P. M.; Rizzi, Cécile; Plénet, Juliette Sirieix; Passos, HelenaBio-based ionic liquids (ILs) are being increasingly sought after, as they are more sustainable and eco-friendly. Purines are the most widely distributed, naturally occurring N-heterocycles, but their low water-solubility limits their application. In this work, four purines (theobromine, theophylline, xanthine, and uric acid) were combined with the cation tetrabutylammonium to synthesize bio-based ILs. The phys...
A HNO3-responsive aqueous biphasic system for metal separation: application tow...
Schaeffer, Nicolas; Vargas, Silvia J. R.; Passos, Helena; Brandão, Paula; Nogueira, Helena I. S.; Svecova, Lenka; Papaiconomou, NicolasAn acidic aqueous biphasic system (AcABS) presenting a desired and reversible phase transition with HNO3 concentration and temperature was developed herein as an integrated platform for metal separation. The simple, economical, and fully incinerable (C,H,O,N) AcABS composed of tetrabutylammonium nitrate ([N4444][NO3])+HNO3 +H2O was characterized and presented an excellent selectivity towards CeIV against other ...
Using coarse-grained molecular dynamics to understand the effect of ionic liqui...
Pérez-Sánchez, Germán; Schaeffer, Nicolas; Lopes, André M.; Pereira, Jorge F. B.; Coutinho, João A. P.This study is aimed to enhance the understanding of the interaction between ionic liquids (ILs) and non-ionic Pluronic triblock copolymers in aqueous two-phase micellar systems (ATPMS) used for the selective separation/purification of hydrophobic biomolecules. The ILs allow a precise control of the cloud point phase separation temperature (CPT), particularly important when the stability of the molecule is highl...
Unravelling the interactions between surface-active ionic liquids and triblock ...
Pérez-Sánchez, Germán; Vicente, Filipa A.; Schaeffer, Nicolas; Cardoso, Inês S.; Ventura, Sónia P. M.; Jorge, Miguel; Coutinho, João A. P.The tunable properties of surface-active ionic liquids (SAILs) and Pluronics are dramatically magnified by combining them in aqueous solutions. The thermo-controlled character of both, essential in the extraction of valuable compounds, can be fine-tuned by properly selecting the Pluronic and SAIL nature. However, further understanding of the nanoscale interactions directing the aggregation in these complex mixt...
Integrated leaching and separation of metals using mixtures of organic acids an...
Vargas, Silvia J. R.; Passos, Helena; Schaeffer, Nicolas; Coutinho, João A. P.In this work, the aqueous phase diagram for the mixture of the hydrophilic tributyltetradecyl phosphonium ([P44414]Cl) ionic liquid with acetic acid (CH3COOH) is determined, and the temperature dependency of the biphasic region established. Molecular dynamic simulations of the [P44414]Cl + CH3COOH + H2O system indicate that the occurrence of a closed "type 0" biphasic regime is due to a "washing-out" phenomenon...