Ionic Liquid Cyphos Research Articles

A novel Cyphos IL 104-based polymer inclusion membrane (PIM) probe to mimic biofilm zinc accumulation.

The presence of Zn in surface waters from abandoned mining zones is a critical issue since excess Zn concentrations may affect aquatic life and whole ecosystems. We present, for the first time, a simple tool based on a polymer inclusion membrane (PIM) intended to monitor Zn in river water by mimicking metal accumulation in the biofilm. The PIM-based probe contains a polymeric membrane prepared using cellulose triacetate (CTA, 50% w/w) as the base polymer, nitrophenyloctyl ether (NPOE) as the plasticizer (20% w/w), and the ionic liquid (IL) Cyphos 104 as the extractant (30% w/w). The accumulation of Zn in the acceptor phase (0.01 M HNO3) was evaluated for different free metal concentrations at 4 h accumulation time resulting in a good correlation between the free metal concentration and the accumulated one. We also found that the metal accumulated agrees with the free metal fraction upon addition of EDTA in the donor solution. The results for Zn accumulation with the PIM-based probe were found to be comparable to those obtained for a biofilm that was grown in a stream from an abandoned mine area and subsequently translocated to the laboratory and put in contact with Zn polluted stream water, so confirming the effectiveness of this new probe in mimicking Zn accumulation in the biofilm.

Studies on the solvent extraction of indium (III) from aqueous chloride medium using Cyphos IL 104

With inimitable chemical and physical properties makes indium critical for a wide variety of high technology, chemical, metallurgical and pharmaceutical industries. As conferred by its location in the periodic table near the borderline between metals and non-metals; indium shows ductility, malleability, conductivity and transparency. In particular, the last two properties are the main reason for indium use in the semiconductor industry for flat panel displays and screens manufacturing by far the most important applications of indium in technical uses. The present study emphasized the extraction ability of a phosphonium based ionic liquid Cyphos IL 104 (trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl) phosphinate) towards indium(III) extraction from acidic chloride medium. The effect of various parameters such as equilibrium time, acid concentration, chloride ion and hydrogen ion was investigated on In(III) extraction. Quantitative extraction of 97.2% was attained with 0.005 mol/L Cyphos IL 104 in toluene at 2.0 mol/L HCl. The effect of thermodynamic parameters i.e., ΔH°, ΔS° and ΔG° were also studied which suggested that the extraction process was endothermic and spontaneous that moves in the forward direction. Using 0.1 mol/L HCl, 100% of indium(III) was recovered from the loaded organic phase.

Non-aqueous solvent extraction of indium from an ethylene glycol feed solution by the ionic liquid Cyphos IL 101: speciation study and continuous counter-current process in mixer-settlers.

A solvometallurgical process for the separation of indium(iii) and zinc(ii) from ethylene glycol solutions using the ionic liquid extractants Cyphos IL 101 and Aliquat 336 in an aromatic diluent has been investigated. The speciation of indium(iii) in the two immiscible organic phases was investigated by Raman spectroscopy, infrared spectroscopy, EXAFS and 115In NMR spectroscopy. At low LiCl concentrations in ethylene glycol, the bridging (InCl3)2(EG)3 or mononuclear (InCl3)(EG)2 complex is proposed. At higher lithium chloride concentrations, the first coordination sphere changes to two oxygen atoms from one bidentate ethylene glycol ligand and four chloride anions ([In(EG)Cl4]−). In the less polar phase, indium(iii) is present as a tetrahedral [InCl4]− complex independent of the LiCl concentration. After the number of theoretical stages had been determined using a McCabe–Thiele diagram for extraction by Cyphos IL 101, the extraction and scrubbing processes were performed in lab-scale mixer–settlers to test the feasibility of working in continuous mode. Indium(iii) was extracted quantitatively in four stages, with 19% co-extraction of zinc(ii). The co-extracted zinc(ii) was scrubbed selectively in six stages using an indium(iii) scrub solution. Indium(iii) was recovered from the loaded less polar organic phase as indium(iii) hydroxide (98.5%) by precipitation stripping with an aqueous NaOH solution.

Solvent Extraction of Metal Ions from Sulfate Solutions Obtained in Leaching of Spent Ni-MH Batteries

Abstract The nickel metal hydride batteries (Ni-MH) are used in many electronic equipment, like cell phones, computers, cameras as well as hybrid cars. Spent batteries can be a rich source of many metals, especially rare earth elements (REE), such as lanthanum (La), cerium (Ce), neodymium (Nd), praseodymium (Pr), samarium (Sm), gadolinium (Gd). Ni-MH batteries also contain iron (Fe) as well as non-ferrous metals, i.e. nickel (Ni), cobalt (Co), zinc (Zn), manganese (Mn), etc. Leaching of such waste with sulfuric acid solutions is one among many methods recovering of useful metals in hydrometallurgical processes. The main aim of this work was separation of metal ions from pregnant leach liquor (PLL) by solvent extraction using phosphorous compounds and ionic liquids (ILs). The initial pH of the aqueous solution was 0.1. Di (2-ethylhexyl) phosphoric acid (D2EHPA), bis (2,2,4-trimethylpentyl) phosphinic acid (Cyanex 272), and phosphoniumionic liquid – trihexyl (tetradecyl) phosphonium bis (2,4,4-trimethylpentyl) phosphinate (Cyphos IL 104) were used as the selective extractants. The initial concentration of the extractants in an organic phase was equal to 0.1 mol∙dm−3. The obtained results show that the highest extraction efficiency was obtained for Fe(III) and Zn(II) in extraction experiments with 0.1 M D2EHPA at pH of 0.1. Ni(II), Co(II) and REE remained in the aqueous solutions. In the next stage, REE were extracted with the mixture of 0.1 M Cyanex 272 and 0.1 M Cyphos IL 104 at pH equal to 3.8. Finally, Ni(II) and Co(II) ions were efficiently removed from the aqueous phase using 0.1 M solution of Cyphos IL 104 at pH around 5.4.

Mechanistic investigation of facilitated transport of gold(III) from HCl media using ionic liquid Cyphos IL102 as carrier across a supported liquid membrane

The transport of gold(III) across a supported liquid membrane containing the ionic liquid Cyphos IL102 (trihexyl(tetradecyl)phosphonium bromide) in Solvesso 100 has been investigated. The investigation was carried out under various experimental variables affecting to the transport process: stirring speed in the aqueous feed solution, HCl and gold(III) concentrations in this same phase, and carrier concentration in the membrane phase. The transport of gold(III) was compared against the transport of Fe(III), Cu(II), and Ni(II) from aqueous solutions containing the four elements, whereas the performance of Cyphos IL102 was compared, with respect to the gold transport, against other potential carriers for gold(III) from this acidic medium. Gold can be recovered in the strip solution as zero valent gold nanoparticles.

Characterization of Polymer Inclusion Membranes (PIMs) Containing Phosphonium Ionic Liquids as Zn(II) Carriers

Phosphonium ionic liquids (IL), i.e., trihexyl(tetradecyl)phosphonium chloride (Cyphos IL 101), trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (Cyphos IL 104), and tributyl(tetradecyl)phosphonium chloride (Cyphos IL 167), were used as ion carriers in CTA or PVC-based polymer inclusion membranes (PIM). Up to now, the morphology and structure of PIMs with phosphonium ILs have not been characterized in detail. Thus, the following techniques were proposed in this paper—contact angle measurements, FT-IR, XRD, DSC, AFM, and SEM—to analyze the influence of PIM morphology on the efficiency of Zn(II) transport. CTA-based membranes appeared to be more hydrophilic, with a more expanded and rough surface that allowed better accessibility of the metal ions to the membrane. PVC-based PIMs were more hydrophobic and completely amorphous, and their surface showed less diversity, resulting in worse accessibility. Also, PIM stability after five cycles of transport processes was examined.

Multi-elemental ionic liquid-based solvent bar micro-extraction of priority and emerging trace metallic pollutants (Cd, Ag, Pd) in natural waters.

Transition metals Cd, Pd and Ag are toxic even at very low concentration. Cd is considered a priority substance; while, Pd and Ag are emerging pollutants. Membrane technologies have been applied for their extraction; however, they require important amounts of reagents, time and energy. Additionally, effective reagents for metal extraction in saline natural waters are limited. In this case, hollow fiber liquid phase micro-extraction with a configuration of solvent bar (SBME) using the ionic liquid Cyphos® 101 as extractant is proposed. Optimized conditions for SBME of Cd, Ag and Pd were 50% Cyphos® 101 in the organic solution, extraction time 30 min and 800 rpm stirring rate. Leaching was in all cases lower than 0.1%. Metallic concentrations were measured by flame atomic absorption spectroscopy. The method was applied to the extraction of Ag, Cd and Pd in natural water samples. Except for waste water, Pd extraction was higher than 90% in all cases. Cd (≈100%) and Ag (93-95%) offered their best results for saline samples. Concluding, the proposed system is a low cost and green methodology that allows a simple and fast extraction of trace pollutants such as Ag, Cd and Pd in different natural waters, including highly saline samples.

Thermal stability of trihexyl(tetradecyl)phosphonium chloride.

Dynamic TGA studies of phosphonium ionic liquids have reported thermal stabilities of 300 °C or higher for these compounds. This is often an overestimation of the real thermal stability. The chosen technique as well as the experimental parameters can influence the thermal stability. In this paper, the thermal stability of commercially available Cyphos IL 101 is studied. The effect of the nature of the atmosphere (air or inert gas), the purity of the sample, the heating rate and presence of a metal on the short-term and long-term stability of commercial Cyphos IL 101 is investigated. The thermal decomposition products are characterized using thermogravimetric analysis coupled to mass spectrometry (TGA-MS). Impurities present and higher heating rates lead to an under- and overestimation of the thermal stability, respectively. The presence of oxygen leads to a lower thermal stability. In contrast, adding metal chlorides to the ionic liquid causes an increase in the thermal stability. The chloride anions are coordinated to the metal ion, so that the Lewis basicity of the anions is reduced. Also this paper gives insights in the behavior of Cyphos IL 101 at high temperatures, which is of relevance for possible application of this ionic liquid in high-temperature industrial processes.

Studies on extraction of gallium (III) from chloride solution using Cyphos IL 104 and its removal from photodiodes and red mud

An efficient solvent extraction process was developed for extraction of gallium (III) from acidic chloride medium using the ionic liquid Cyphos IL 104 diluted with toluene. The kinetics of gallium extraction was very fast. The extraction percent of gallium was found to increase with increase in hydrochloric acid concentration in the feed and 99.8% extraction of gallium was achieved with 3M HCl. The stoichiometry of the formation of gallium-Cyphos IL 104 complex was found to be 1:1 and the corresponding extracted species was proposed as [R3R′PGaCl4]. Presence of sodium chloride increased the percentage extraction of gallium. The thermodynamic parameters calculated from the temperature variation study suggested the process was spontaneous and endothermic. Loading capacity of the ionic liquid was executed and the stripping study of the loaded organic phase was investigated using four stripping agents namely HCl, H2SO4, NH3 and HNO3 each having concentrations of 0.5mol/L. It was found that HCl performance was poor and the rest three could recover >90% gallium from the loaded organic phase. Binary separation studies were carried out using commonly associated metal ions with gallium (Al (III)/Zn (II)/Fe (III)/Cu (II)/Ni (II)) and the process was extended to study the recovery of gallium from leach liquors of photodiodes and red mud sample.

Solvent Extraction and Stripping of Fe and Mn from Aqueous Solution Using Ionic Liquids as Extractants

In the hydrometallurgical recovery process of Fe and Mn from ores and scrap, hydrochloric acid was used to leach these metals in the aqueous solution. Following this, solvent extraction techniques were employed to recover these metals from the chloride-rich solution. Recently, ionic liquids (ILs) have been widely employed in solvent extraction because of their unique characteristics. In this study, recoveries of Fe and Mn were carried out by using solvent extraction and stripping with ionic liquids, Aliquat 336 and Cyphos IL 101. In the extraction process, the metals were extracted from aqueous solution to organic solution containing IL by the anion exchange reaction between the anion of ionic liquid and the anionic chlorocomplexes such as FeCl4– and MnCl3–. Sodium thiosulfate was the only one stripping agent, which gave the quantitative recovery of Fe (III) from Aliquat 336 solution. Mn (II) was effectively stripped by water from Aliquat 336 solution. The stripping percentages in metal-Cyphos IL 101 system were lower than those of metal-Aliquat 336 system. Aliquat 336 is found to be better extractant than Cyphos IL 101 because of its high stripping performance.

Non-dispersive extraction of gold(III) with ionic liquid Cyphos IL101

The permeation of gold(III), through a supported liquid membrane (SLM), in flat-sheet operational mode, impregnated with Cyphos IL101 (ionic liquid with a quaternary phosphonium salt as active substance) in Solvesso 100 has been investigated. The transport of gold(III) has been studied under various experimental conditions: stirring speed of the aqueous phases, initial metal and carrier concentrations, HCl concentration in the source phase, etc. The overall mass transfer coefficient was calculated as 0.19 cm/min and the thickness of the aqueous boundary layer was of 3.2 × 10−3 cm. The performance of Cyphos IL101 has been studied with respect to other carriers and also the selectivity of the membrane-carrier system on various metal-bearing aqueous solutions. Gold is recovered in the strip phase as nanogold.

Cobalt(ii)/nickel(ii) separation from sulfate media by solvent extraction with an undiluted quaternary phosphonium ionic liquid

Co(ii) is separated from Ni(ii) in sulfate media by extraction with the ionic liquid Cyphos IL 101 in its chloride and thiocyanate form.

A synergistic extraction strategy by [N1888][SOPAA] and Cyphos IL 104 for heavy rare earth elements separation

Synergistic extraction of trivalent rare earth element (REE) from hydrochloride solution using mixtures of methyltrioctylammonium sec-octylphenoxy acetate ([N1888][SOPAA]) and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate ([P66614][BTMPP], Cyphos IL 104) has been investigated. Extraction mechanism of the ionic liquid (IL) extractants for Lu(III) was indicated to be ion association using slope analysis method and Infra Red (IR) spectra. The IL based extraction system revealed pronouncedly synergistic effects in the extraction of Lu(III). The largest synergistic enhancement coefficient from different mole fractions of [N1888][SOPAA] and [P66614][BTMPP] reached 40.47, which was much larger than that of 3.05 from sec-octylphenoxy acetic acid (HSOPAA, CA-12) and bis(2,4,4-trimethylpentyl)phosphinic acid (HBTMPP, Cyanex272) under the same conditions. The loaded Lu(III) could be full stripped using hydrochloric acid. This paper reveals a potential application in heavy REE separation.

Solvent Extraction and Separation of Trivalent Lanthanides Using Cyphos IL 104, a Novel Phosphonium Ionic Liquid as Extractant

ABSTRACTSolvent extraction of trivalent lanthanides from chloride solution using a novel ionic liquid Cyphos IL 104 (trihexyl(tetradecyl)phosphonium bis-2,4,4-(trimethylpentyl) phosphinate or [R4PA]) has been investigated, while comparing the results with that of its precursors trihexyl(tetradecyl)phosphonium chloride [R4PCl or Cyphos IL 101], Cyanex 272 [HA] and their equimolar mixture. The results also indicate very high extractability of Cyphos IL 104 toward trivalent lanthanides. Unlike the conventional acidic extractants, extraction of trivalent lanthanides with Cyphos IL 104 increases the equilibrium pH of the aqueous phase due to the preferential extraction of acid over the lanthanide ions. Extraction mechanism has been established by studying the extraction of neodymium(III) with the ionic liquid as a function of the concentrations of Cyphos IL 104 and chloride ions. Separation studies of trivalent lanthanides from a mixed solution containing 1 × 10−4M each of La, Nd, Gd, and Lu with Cyphos IL 104 or Cyanex 272 indicate that Cyphos IL 104 is a better extractant in terms of extraction coefficient, but Cyanex 272 exhibits better selectivity toward heavier lanthanides. The prospects of stripping and regeneration of ionic liquid (Cyphos IL 104) have also been discussed in the present study.

Highly selective separation of individual platinum group metals (Pd, Pt, Rh) from acidic chloride media using phosphonium-based ionic liquid in aromatic diluent

An effective solvent extraction-based method has been developed to recover individually platinum group metals (Pd, Pt, and Rh) with high purity from acidic chloride media using phosphonium-based ionic liquid Cyphos IL 101 in aromatic solvent.

Application of Phosphonium Ionic Liquids as Ion Carriers in Polymer Inclusion Membranes (PIMs) for Separation of Cadmium(II) and Copper(II) from Aqueous Solutions.

Facilitated transport through polymer inclusion membranes (PIMs) is a promising method for simultaneous separation and removal of valuable and toxic metal ions from aqueous solutions. Recently, ionic liquids (ILs) have been used as extracting agents for metal ions due to their unique physicochemical properties. This paper presents research on the facilitated transport of cadmium(II) and copper(II) ions from aqueous chloride solutions through PIMs with phosphonium ILs as new selective ion carriers. Cellulose triacetate membranes containing o-nitrophenyl octyl ether (ONPOE) as a plasticizer and Cyphos IL 101 [trihexyl(tetradecyl)phosphonium chloride] or Cyphos IL 104 [trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate] as the ion carriers have been prepared and applied for investigations. Cd(II) ions were transported preferably from hydrochloric acid solutions containing Cu(II) ions through the PIMs. Higher selectivity coefficient of Cd(II) over Cu(II) (SCd/Cu) from 0.1 mol·dm−3 hydrochloric acid was obtained for PIM with Cyphos IL 104 as the ion carrier. The influence of HCl and NaCl concentrations in the source phase on metal ion transport across PIM doped with Cyphos 104 was studied. It was found that the initial fluxes of Cd(II) and Cu(II) increase with increasing chloride ions concentration in the source phase. The selectivity coefficient for Cd(II) over Cu(II) decreases with increasing HCl concentration in the source phase. The results suggest that the separation system presented in this paper can be useful for the removal of Cd(II) from acidic chloride solutions in the presence of Cu(II).

Cr(VI) transport via a supported ionic liquid membrane containing CYPHOS IL101 as carrier: System analysis and optimization through experimental design strategies

Chromium(VI) transport through a supported liquid membrane (SLM) system containing the commercial ionic liquid CYPHOS IL101 as carrier was studied. A reducing stripping phase was used as a mean to increase recovery and to simultaneously transform Cr(VI) into a less toxic residue for disposal or reuse. General functions which describe the time-depending evolution of the metal fractions in the cell compartments were defined and used in data evaluation. An experimental design strategy, using factorial and central-composite design matrices, was applied to assess the influence of the extractant, NaOH and citrate concentrations in the different phases, while a desirability function scheme allowed the synchronized optimization of depletion and recovery of the analyte. The mechanism for chromium permeation was analyzed and discussed to contribute to the understanding of the transfer process. The influence of metal concentration was evaluated as well. The presence of different interfering ions (Ca2+, Al3+, NO3−, SO42−, and Cl−) at several Cr(VI): interfering ion ratios was studied through the use of a Plackett and Burman experimental design matrix. Under optimized conditions 90% of recovery was obtained from a feed solution containing 7mgL−1 of Cr(VI) in 0.01moldm−3 HCl medium after 5h of pertraction.

Bismuth(III) recovery from hydrochloric acid solutions using Amberlite XAD-7 impregnated with a tetraalkylphosphonium ionic liquid

An Ionic Liquid (IL) (Cyphos IL 101: tetradecyl(trihexyl)phosphonium chloride was immobilized on Amberlite XAD-7 for preparing extractant impregnated resins (EIRs). The IL content was varied between 59 and 586mgILg−1 EIR. The EIRs were tested for Bi(III) recovery from (0.01–8M) HCl solutions. The EIRs were very efficient at extracting Bi(III), the sorption efficiency increased with IL content in the resin, but decreased with HCl concentration. Bi(III) was extracted through an ion exchange mechanism involving the binding of its anionic chloro-complexes to IL phosphonium cation. Sorption isotherms were fitted with the Langmuir equation and they were found to be very favorable with maximum sorption capacities up to 84.3mgBig−1 EIR (in 1M HCl solution using an EIR with 401mgLig−1 EIR at 20°C). Temperature slightly influenced Bi(III) sorption capacity. Bi(III) recovery selectivity was studied in bimetallic (1M HCl) solutions, where, Cu(II) and Ni(II) were not removed but Zn(II) was partially extracted slightly affecting Bi(III) recovery. Sorption kinetics was not affected by agitation speed: the resistance to film diffusion is not the limiting step. The uptake kinetics were controlled by the resistance to intraparticle diffusion. The intraparticle diffusivity coefficients decreased with increasing IL loading but increased with temperature due to the decrease of IL viscosity (in the EIRs). Bi(III) can be easily desorbed from EIRs using either citric acid, nitric acid or sodium sulfate solutions. The EIRs could be recycled maintaining high efficiencies for sorption and desorption for at least five cycles.

Ionic liquids as a carrier for chloride reduction from brackish water using hollow fiber renewal liquid membrane

High concentration of chloride ions in continental water is a great problem for the exploitation of these natural resources. In industry, the use of this water involves additional conditioning steps. For drinking water and irrigation uses, the Cl− must be reduced by conventional water treatment processes, like ion exchange or reverse osmosis, but for large scale production these techniques could be very expensive due to resin regeneration or energy costs. The possibility of using supported liquid membranes (SLM) with ionic liquids (IL), Aliquat 336, Cyphos IL 101 and Cyphos IL 167, as carriers to exchange Cl− for HCO3− anion has been shown to work. The reversibility of this anion exchange was corroborated by solvent extraction experiments and implemented in flat sheet supported liquid membrane (FSSLM) and hollow fiber renewal liquid membrane technologies (HFRLM). About double transport values have been obtained in HFRLM compared to SLM and 1h is the time enough to reduce the chloride concentration up to 250mg/L using HFRLM at the best experimental condition. The results obtained allow us to be optimistic about the implementation of this technology on a large scale to chloride reduction in drinking water when the source is inadequate for direct use.

Solvent impregnated resin prepared using ionic liquid Cyphos IL 104 for Cr(VI) removal

Ionic liquid (IL) trihexyl (tetradecyl) phosphonium bis 2,4,4-trimethylpentylphosphinate (Cyphos IL 104) was impregnated on XAD–7 resin. The solvent impreganated resin (SIR) was prepared and applied in Cr(VI) removal. The morphology and the thermal stability of the resins were explored. The effects of equilibrium time and initial pH value on Cr(VI) adsorption were investigated. Adsorption isotherm, separation and desorption of the SIR, and selectivity of SIR were also explored. The results show that Cyphos IL 104 exists in the inner XAD-7 resin, and the optimum pH value range of the SIR for Cr(VI) extraction is 0 to 2. When NaOH used as desorption solution, the Cr(VI) can be effectively desorbed from the SIR.