Methylimidazolium Hexafluorophosphate Research Articles

A novel atropine electrochemical sensor based on silver nano particle-coated Spirulina platensis multicellular blue-green microalga

In this work, Atropine as the anticholinergic drug was measured using the environmentally friendly sensor. In this regard, Self-cultivated Spirulina platensis with electroless silver was employed as a powder amplifier in carbon paste electrode modification. Also, 1-Hexyl-3 methylimidazolium Hexafluorophosphate (HMIM PF6) ion liquid as a conductor binder was used in the suggested electrode construction. Atropine determination was investigated by voltammetry methods. According to voltammograms, the electrochemical behavior of atropine depends on pH, and pH 10.0 was used as the optimal condition. Moreover, the diffusion control process for the electro-oxidation of atropine was verified by the scan rate study, so the diffusion coefficient (D∼ 3.0136×10−4cm2/sec) value was computed from the chronoamperometry study. Furthermore, responses of the fabricated sensor were linear in the concentration range from 0.01 to 800 μM, and the lowest detection limit of the Atropine determination was obtained at 5 nM. Moreover, the stability, reproducibility, and selectivity factors of the suggested sensor were confirmed by the results. Finally, the recovery percentages for atropine sulfate ampoule (94.48–101.58), and water (98.01–101.3) approve of the applicability of the proposed sensor to Atropine determination in real samples.

Synergistic Effects of 1-Octyl-3-Methylimidazolium Hexafluorophosphate and Cellulose Nanocrystals on Improving Polyacrylate Waterborne Anti-Corrosion Coatings

In this study, three copolymers of poly(methyl methacrylate) and poly(butyl acrylate) (PMMA-co-PBA) latex containing 1-octyl-3 methylimidazolium hexafluorophosphate (C8mimPF6), cellulose nanocrystals (CNCs), and C8mimPF6-CNCs were successfully synthesized through mini emulsion polymerization. These novel composites were each coated on mild steel panels and tested for their anti-corrosion performance by immersion of the coated samples in 3.5 wt% sodium chloride (NaCl) solution over a certain period. The synergistic anti-corrosion effects of the C8mimPF6-CNCs sample led to the highest coating resistance, charge transfer resistance, and corrosion inhibition efficiency and the lowest diffusion coefficient and corrosion rate. The proposed synergistic mechanism revealed that CNCs enhanced the barrier effect of the coating while C8mimPF6 inhibited corrosion when released.

Highly sensitive electrochemical sensor based on carbon paste electrode modified with graphene nanoribbon-CoFe2O4@NiO and ionic liquid for azithromycin antibiotic monitoring in biological and pharmaceutical samples.

In this report, Azithromycin (Azi) antibiotic was measured by carbon paste electrode (CPE) improved by graphene nanoribbon-CoFe2O4@NiO nanocomposite and 1-hexyl-3 methylimidazolium hexafluorophosphate (HMIM PF6) as an ionic liquid binder. The electrochemical behavior of Azi on the graphene nanoribbon-CoFe2O4@NiO/HMIM PF6/CPE is investigated by voltammetric methods, and the results showed that the modifiers improve the conductivity and electrochemical activity of the CPE. According to obtained data, the electrochemical behavior of Azi is related to pH. under optimum conditions, the sensor has linear ranges from 10µM to 2mM with a LOD of 0.66µM. The effect of scan rate and chronoamperometry were studied, which showed that the Azi electro-oxidation is diffusion controlled with the diffusion coefficient of 9.22 × 10-6 cm2/s. The reproducibility (3.15%), repeatability (2.5%), selectivity, and stability (for 30days) tests were investigated, which results were acceptable. The actual sample analysis confirmed that the proposed sensor is an appropriate electrochemical tool for Azi determination in urine and Azi capsule.

Studies acoustic behaviour of the binary mixture of 1-Butyl-3-methylimidazolium hexafluorophosphate with 1- hexanol at 298.15 K

Densities and speeds of sound and their excess properties for 1-butyl-3- methylimidazolium Hexafluorophosphate [Bmim] [PF6] with 1-Hexanol over the entire range of mole fraction are reported at temperature 298.15 K and atmospheric pressure. Isentropic and excess isentropic compressibility for ionic liquid with 1-Hexanol were calculated from the experimental results. The excess values are fitted to the Redlich−Kister polynomial equation to estimate the binary coefficients and standard error between the experimental and calculated values. The measured speeds of sound were compared to the values obtained from Schaaffs' collision factor theory, Jacobson's intermolecular free length theory of solutions and Nomoto’s relation. The theoretical results obtained from these relations fairly agrees within the experimental precision. Further, the molecular interactions involved in IL binary mixture system were studied.

Copper recovery by slurry electrolysis using ionic liquids from waste printed circuit boards

<p>The regulatory framework of heavy metal pollution associated with electronic waste is prevalent all over the world. As a result of technological advancement and change in consumer patterns, the life span of electrical and electronic products has been shortened. This has contributed to the emergence of massive amounts of electronic waste that needs to be handled. With the exponential growth of the telecommunications sector, the recycling of useful resources from electronic waste devices, especially mobile phones, is of great significance. Besides, the presence of valuable metals enables the recycling of electronic waste potentially appealing. In this research, numerous types of ionic liquids like Butyl methylimidazolium hexafluorophosphate [Bmim][PF6], Butyl methylimidazolium chloride [Bmim][Cl], Ethyl methylimidazolium chloride [Emim][Cl] and Butyl methylimidazolium tetrafluoroborate [Bmim][BF4] were used to analyze the copper leaching behavior of electronic mobile handset devices. Several influential aspects on the leaching efficiency of copper including different types of ionic liquid, temperature and leaching time have been examined. The findings showed [Bmim][PF6] and [Emim][Cl] were better ionic liquids in appropriate conditions for high copper leaching rates.</p>

Tribological properties of 1 - octyl – 3 - methylimidazolium lactate ionic liquid as a lubricant additive

This study examined the tribological properties of the IL 1 - octyl – 3 - methylimidazolium lactate (L-L108), which is used as an additive to SAE 10W-40 and PEG400, for steel–steel contacts. The ionic liquids 1 - octyl – 3 - methylimidazolium hexafluorophosphate (L-P108) and 1 - octyl – 3 - methylimidazolium tetrafluoroborate (L-B108) were used as reference lubricants because their molecular structures are similar to that of L-L108. Tribological experiments were performed on a ball-on-disk contact tribometer for 60 min (at room temperature, with a load of 5 N, sliding speed of 0.38 m/s, and relative humidity of 30%–55%). Sliding tests showed that the lubricating performance was improved when L-L108 was used as the SAE 10W-40 and PEG400 additive. After the sliding tests, the wear scar was analyzed using white light vertical scanning interferometry and X-ray photoelectron spectroscopy (XPS). The three-dimensional images and cross-sectional line profiles showed the topography of the wear surface. When L-L108 was blended into 10W-40 and PEG400, the binding energy values of C, N, O, and Fe changed compared with a neat steel surface. The XPS analysis indicated that a tribochemical reaction occurred between the mixture and metal substrate during the friction process. This formed a chemical reaction film on the steel surface, and could have been the reason for the excellent tribological performance.

Simulation study of biomethane liquefaction followed by biogas upgrading using an imidazolium-based cationic ionic liquid

To satisfy the ever-increasing global energy demand, biomethane is considered a promising sustainable and renewable energy source. Biomethane can be transported either in the gaseous phase (through pipelines, over a small distance) or in the liquid phase (through shipping, over a long distance). For transportation over long distances, liquefaction is one of the most economic and feasible approaches so far. However, biomethane is obtained as a result of biogas upgrading, i.e., CO2 removal from biogas. Conventionally, CO2 is removed through amine-based absorption, which consumes large amounts of energy to regenerate the amine-based solvent. Liquefaction of methane (obtained either from fossil-based or renewable resources) has also been recognized as an energy-intensive process. Hence, the major issue associated with biogas upgrading and subsequent biomethane liquefaction is their high energy consumption, which ultimately affords a cost-intensive process. In this context, we propose a simulation based an economical and energy efficient process for biomethane liquefaction following biogas upgrading using an ionic liquid (1-butyl–3–methylimidazolium hexafluoro phosphate [Bmim][PF6]). As such, biogas can be upgraded at an energy expense of 1.1048 kWh/kmol, while 11.26 kWh/kmol of energy is used for biomethane liquefaction. The specific total annualized cost for the proposed integrated process was calculated as $519.3/kg-biogas.

FLUORESCENCE ENHANCEMENT OF Al3+– SODIUM MORIN–5–SULFONATE COMPLEX BY IMIDAZOLIUM IONIC LIQUID AND ITS APPLICATION IN DETERMINATION OF Al3+ IONS IN AN AQUEOUS SOLUTION

This study describes the preparation of sodium morin–5–sulfonate (NaMSA) as a new reagent for the determination of aluminium(III) (Al3+) ions based on the formation of a ternary complex. The complex consists of Al3+, NaMSA, and 1–Butyl–3–methylimidazolium hexafluorophosphate (BMIM–PF6). It was found that this method was sensitive compared to the binary complex of Al3+ and NaMSA. The ternary complex was excited at 420 nm, and the fluorescence signal was measured at 518 nm. Maximum fluorescence signal produced at pH 5.0 (acetic acid–acetate buffer), with 0.02% v/v BMIM–PF6 and 1.0 × 10-4 molL-1 of NaMSA. The calibration graph in linear up to 10 mgL-1 with the calculated detection limit of 0.017 mgL-1. Effect of foreign ions towards the ternary complex was also studied. Finally, the method was applied in the determination of Al3+ ions in water samples, and satisfactory results were obtained.

A Poly(ionic liquid) Gel Electrolyte for Efficient all Solid Electrochemical Double-Layer Capacitor

Polyionic liquid based gels have stimulated significant interest due to their wide applications in flexible electronics, such as wearable electronics, roll-up displays, smart mobile devices and implantable biosensors. Novel supported liquid gel electrolyte using polymerisable ionic liquid and an acrylate monomer, has been developed in this work by entrapping ionic liquid during polymerisation instead of post polymerisation impregnation. The chemically crosslinked polyionic liquid gel electrolyte (PIL) is prepared using 2-hydroxyethylmethacrylate (HEMA) monomer and a polymerisable ionic liquid, 1,4-di(vinylimidazolium)butane bisbromide (DVIMBr) in an ionic liquid (IL- 1-butyl-3 methylimidazolium hexafluorophosphate) as the polymerisation solvent, which resulted in in-situ entrapment of the IL in the gel during polymerisation and crosslinking of the polymer. The supported liquid gel electrolyte (SLG) material was characterised with thermal analysis, infrared spectroscopy, and dynamic mechanical analysis, and was found to be stable with good mechanical properties. The electrochemical analysis showed that these chemically cross-linked PIL gel electrolyte-supported ILs are suitable for solid-state, flexible supercapacitor applications.

Carbon Paste Electrode Modified with ZrO2 Nanoparticles and Ionic Liquid for Sensing of Dopamine in the Presence of Uric Acid

A novel carbon paste electrode modified with ZrO2 nanoparticles and an ionic liquid (n-hexyl-3- methylimidazolium hexafluorophosphate) was fabricated. The electrochemical study of the modified electrode, as well as its efficiency for simultaneous voltammetric oxidation of dopamine and uric acid is described. The electrode was also employed to study the electrochemical oxidation of dopamine and uric acid, using cyclic voltammetry, chronoamperometry and square wave voltammetry as diagnostic techniques. Square wave voltammetry exhibits linear dynamic range from 1.0 × 10−6 to 9.0 × 10−4 M for dopamine. Also, square wave voltammetry exhibits linear dynamic range from 9.0 × 10−6–1.0 × 10−3 M for uric acid. The modified electrode displayed strong function for resolving the overlapping voltammetric responses of dopamine and uric acid into two well-defined voltammetric peaks. In the mixture containing dopamine and uric acid, the two compounds can be well separated from each other with potential difference of 155 mV, which is large enough to determine dopamine and uric acid individually and simultaneously. Finally, the modified electrode was used for determination of dopamine and uric acid in real samples.

Electrical Conductivity of Methylimidazolium Hexafluorophosphate Ionic Liquid in the Presence of Colloidal Silver Nano Particles with Different Sizes and Temperatures

Colloidal nanoparticle could be used for recognition location of tumors and cancer tissue. A simulation of molecular dynamic for colloidal silver nanoparticles (Ag NPs) based on density functional theory (DFT) potential parametrization with different sizes in 1-ethyl-3-methylimidazolium hexafluorophosphate [EMim][PF6] ionic liquid was performed. Then, using Green Kubo formalism, diffusion coefficient for Ag NPs in IL and in the gas phase was calculated. We also calculated diffusion coefficients of anions and cations for pure IL and IL in the presence of different sizes of Ag NPs at different temperatures. The findings showed that the diffusion coefficient of anions and cations increases in proportion with temperature and the sizes of colloidal Ag NPs. Next, cationic transference number for pure IL and IL in the presence of Ag NPs, electrical conductivity of pure IL, and IL with different sizes of Ag NPs were calculated and compared. After that, the calculated diffusion coefficient and electrical conductiv...

Enrichment of the Gamma Oryzanol Level from Rice Bran by Addition of Inorganic Salts on Ionic Liquid 1-Butyl-3- Methylimidazolium Hexafluorophosphate ([BMIM] PF6) Extraction

<p style="text-align: justify;"><strong>Objective:</strong> Rice bran oil has many helath benefit. The biologically active compounds of rice bran oil are fatty acids, squalene, tocopherols, phytosterols, tocotrienols, oryzanol, and polyphenols. Gamma oryzanol is a combination of at least 10 components of ferulic acid esters and alcohols triterpene. Gamma oryzanol has pharmacological activity includes cardiovascular disease, antioxidant, anticancer, antidiabetic, antiulcerogenic, neuroprotective and action immunomodulator. Ionic liquids are an environmentally friendly solvent used in the extraction and separation of bioactive compounds from plants. This study was conducted to evaluate the effect of inorganic salts addition on ionic liquid [Bmim]PF₆ in increasing levels of gamma oryzanol from rice bran. <strong>Method:</strong> In the experiments, IL [Bmim]PF₆ - MAE method was used to separated gamma oryzanol compound, and then was partitioned with hexane after the addition of inorganic salts: KH₂PO₄, NaCl, NaNO₃ and Na₂CO₃, respectively. Gamma oryzanol content was determined by HPLC analysis. A mixture of mobile phase (methanol:acetonitrile:isopropan ol (5:4:1) and isocratic conditions at a wavelength of 327 nm. The flow rate is set at 1 ml / min..Results: The highest levels of &gamma;-oryzanol was produced from the addition in KH₂PO₄ + : [Bmim] PF₆ by 0.26 &plusmn; 0.001 mg/g. The mechanism of salting-out effect of the compound due to the interaction of different types of interactions between solutes (ions of inorganic salts and ionic liquid) and solvent. <strong>Conclusion:</strong> The addition of inorganic salt increased the gamma oryzanol level. The addition of KH₂PO₄ on IL-MAE gave the highest level of gamma oryzanol. <p style="text-align: justify;"><strong>Key words:</strong> [BMIM]PF₆, ionic liquid, &gamma;-oryzanol, IL-MAE, inorganic salts.

Magnetic nanoparticles coated with ionic liquid for the extraction of endocrine disrupting compounds from waters

A hybrid nanomaterial was synthesized to be used in dispersive solid phase microextraction. It consist of a magnetic core (Fe3O4), obtained by coprecipitation covered by a silica (SiO2) layer were the ionic liquid methylimidazolium hexafluorophosphate (MIM-PF6) was attached. The Fe3O4@SiO2@MIM-PF6 nanoparticles have been characterized by microscopy and X-ray diffraction. The chemical composition of the hybrid nanoparticles has been studied by infrared spectroscopy and thermogravimetrical analyses. Finally, its potential in dispersive microextraction was evaluated for the isolation of 11 endocrine disrupting compounds (benzophenones, bisphenol A and parabens) from water samples.For this purpose, 10mg of the Fe3O4@SiO2@MIM-PF6 are added to 100mL of water sample (pH=8, NaCl 30% w/v) dispersed by ultrasound (1min) and vortex stirring (20min). Next, an external magnet is used to recover the MNPs. Later, the analytes are eluted from MNPs with 500μL of methanol under ultrasonic irradiation. 5μL of the extract is finally injected into a liquid chromatograph with tandem mass spectrometric detection (HPLC-MS/MS) for analytes separation and quantification.The proposed microextraction method allows the determination of the target compounds with limits of detection in the range from 0.16 to 1.21μg/L and the linearity was maintained between the limits of quantification and 500μg/L. The precision, expressed as relative standard deviation was better than 8.3%. The recovery study was performed on different water samples obtaining percentages higher than 87%, which demonstrated the applicability of the hybrid sorbent for the selected analytical problem. Moreover, the proposed method provides enrichment factors in the range from 15.4 to 49.2. Butylparaben, benzophenone 3 and benzophenone 6 were detected in the swimming pool water samples analyzed following the proposed microextraction method. The simultaneous presence of analytes from different endocrine disrupting families reveal the need for methodologies including a wider variety of compounds than those currently available.

Ringer tablet-based ionic liquid phase microextraction: Application in extraction and preconcentration of neonicotinoid insecticides from fruit juice and vegetable samples

An efficient, reliable, sensitive, rapid, and green analytical method for the extraction and determination of neonicotinoid insecticides in aqueous samples has been developed using ionic liquid phase microextraction coupled with high performance liquid chromatography–diode array detector. In this method, a few microliters of 1–hexyl–3–methylimidazolium hexafluorophosphate (as an extractant) is added onto a ringer tablet and it is transferred into a conical test tube containing aqueous phase of the analytes. By manually shaking, the ringer tablet is dissolved and the extractant is released into the aqueous phase as very tiny droplets to provide a cloudy solution. After centrifuging the extracted analytes into ionic liquid are collected at the bottom of a conical test tube. Under the optimum extraction conditions, the method showed low limits of detection and quantification between 0.12 and 0.33 and 0.41 and 1.11ngmL–1, respectively. Extraction recoveries and enrichment factors were from 66% to 84% and 655% to 843%, respectively. Finally different aqueous samples were successfully analyzed using the proposed method.

Graphene Quantum Dot-Modified Lipase for Synthesis of L-menthyl Acetate with Improved Activity, Stability and Thermostability

Title: Pseudomonas cepacia lipase modified with Graphene Quantum Dots (GQD) offers a higher activity, stability and thermostability compared to the lipase modified with graphene oxide. Background: GQD presents extraordinary properties attracting extensive attention from scientists in chemistry, physics, materials, biology and other interdisciplinary sciences. However, no research involves the application in biocatalysts in non-aqueous media up to now. In the study, we for the first time reported a promising GQDmodified lipase for the synthesis of l-menthyl acetate. Methods and findings: Pseudomonas capaci lipase was modified with GQD and then used as a biocatalyst for the synthesis of l-menthyl acetate in 1-isobutyl-3- methylimidazolium hexafluorophosphate medium. As contrasts, the reaction was also carried out using bare lipase and graphene oxide-modified lipase as the catalyst. Besides, the modification method of enzyme, the amounts of GQD, the reaction temperature, molar ratio of the two substrates, and reuse of the enzyme were investigated. The result shows that the GQD-modified lipase as a biocatalyst was best among the three enzymes. Under optimal reaction conditions, the reaction reaches the equilibrium within 8 h with a high conversion of lmenthol (97.3%). Its initial enzyme activity and halflifetime were more than 1.08 and 2.07-fold that of the bare lipase, and 1.04 and 1.66-fold that of the graphene oxide-modified lipase, respectively. The lipase was recycled 10 times without substantial diminution in activity. In addition, the GQD-modified lipase also offers a better thermostability compared with bare lipase. These improvements could be attributed to the unique small size and edge effect of GQD. Conclusion: GQD-modified lipase showed a higher activity, stability and thermostability compared to GO- modified lipase. GQD was widely used as a promising material for enzyme modification due to its good biocompatibility and small size.

Ionic liquid-modified silica gel as adsorbents for adsorption and separation of water-soluble phenolic acids from Salvia militiorrhiza Bunge

Abstract In this work, six kinds of different ionic liquid-modified silica were synthesized and characterized with infrared spectroscopy, thermogravimetric analysis, elemental analysis, N 2 adsorption–desorption isotherms and particle size distribution. Then they were used as adsorbents for the preparative separation of water-soluble phenolic acids from Salvia militiorrhiza Bunge for the first time. The effects of various parameters including functional groups of adsorbents, adsorption time, initial concentration, solid–liquid ratio and temperature were investigated in detail. It was found that silica modified with N -methylimidazolium hexafluorophosphate (SiO 2 ·Im + ·PF 6 − ) had most excellent adsorption capacity for target compounds, which reached 99.81 mg/g under the conditions of adsorption time of 30 min, initial sample concentration of 350 mg/L and solid–liquid ratio of 1:1 (mg/mL). Studies showed that the equilibrium data fitted well with Langmuir model of adsorption and the adsorption kinetics was more accurately described by pseudo-second-order model. Thermodynamics parameters including the change of enthalpy, entropy and Gibbs free energy were also analyzed. Furthermore, the water-soluble phenolic acids of Salvia militiorrhiza Bunge were successfully preparatively separated on the normal pressure chromatographic column packed with the SiO 2 ·Im + ·PF 6 − particles to obtain protocatechuic aldehyde, sodium danshensu, rosmarinic acid, lithospermic acid and salvianolic acid B successively. The separation mechanism was investigated on the basis of experimental results and the reusability of the ionic liquid-modified silica gel was also explored. This study provides an useful reference for the preparation separation of natural products and indicates that the ionic liquid-modified silica can be applied in the separation of water-soluble phenolic acids with great prospects.

Crystal Growth, Structure, and Polymorphic Behavior of an Ionic Liquid: Phthalate Derivative of N-Butyl,N-methylimidazolium Hexafluorophosphate

After the multistep synthesis of an original imidazolium hexafluorophosphate ionic liquid, [pbmim][PF6], two polymorphic forms were isolated from methanolic solution and characterized by XRPD, DSC, and Raman spectroscopy. Stable Form A (mp 90.3 °C) was obtained by conventional crystallization at a moderate cooling rate (<10 K/min), whereas metastable Form B (mp 83.2 °C) was spontaneously produced from a liquid–liquid demixing (oiling out) when a faster cooling rate (>10 K/min) was applied. Structural analyses carried out by using single-crystal (Form A) and powder (Form B) X-ray diffraction revealed a rotational disorder of anionic octahedrons and, more interestingly, large conformational differences between cationic moieties caused by their molecular flexibility. Crystal growth of [pbmim][PF6] (Form A) in methanol often leads to numerous crystal defects and revealed that most of them consist of liquid inclusions. The supersaturation ratio (β) appeared to be the predominant factor influencing the crystal growth behavior under isothermal and stagnant conditions. At low β values, a morphological transition from rod-shaped crystals to platelets was observed, presumably caused by a change in the growth mechanism of specific faces. Using high β values promotes either the formation of microscopic (<5 μm) liquid inclusions that become easily detectable upon heating or the appearance of macroscopic inclusions with an hourglass shape.

Electrosynthesis of viologen cross-linked polythiophene in ionic liquid and its electrochromic properties

Utilizing electrochemical reduction of pendant cyanopyridinium ions to cross-link polymeric viologens is well known. In this work, we report electrosynthesis of a thiophene monomer bearing a pendant cyanopyridine moiety in its side chain (Th-CN). Its electropolymerization results in the growth of a polythiophene film which is highly cross-linked by the viologen unit (PTh-V). In order to improve adhesion and insolubility of the as-formed polymer film, we choose the ionic liquid 1-butyl-3 methylimidazolium hexafluorophosphate (BmimPF6), as electrolyte. The obtained polymer film was studied by cyclic voltammetry, FTIR spectroscopy, in situ UV-Vis spectroelectrochemistry and electrochemical impedance spectroscopy (EIS). The CV results showed electrochemical activity both of the viologen and polythiophene moieties. FTIR spectra of the polymer film confirm the formation of viologen by disappearance of the–CN stretching band from the polymer spectrum. EIS studies revealed that both resistive as well as capacitive element controls the charge transfer mechanism. In situ spectroelectrochemical studies of the polymer film shows enhanced electrochromic contrast of polythiophene film due to incorporation of viologen pendant group with coloring characteristics both of the viologen and the polythiophene backbone. An n-doped polymer is a dark blue colored film with coloration efficiency being ca. 97 cm2/C at 625nm while the p-doped polymer is transparent violet in color with coloration efficiency of ca. 12 cm2/C at 775nm. The results showed that the PTh-V film can be used as redox active conducting layer to develop dynamic optoelectronic and electrochromic devices.

Ionic liquid-complex Pd/C system as catalyst for copolymerization of CO and styrene

The copolymerization of CO and styrene catalyzed by Pd/C toward the formation of polyketones (PK)was studied in the N-valeronitrile-N′-methylimidazolium hexafluorophosphate ([C4CNmim]+PF6 -) medium. The synthesized PK was characterized by Fourier transform infrared(FTIR), elemental analysis, 13C-nuclear magnetic resonance (13C-NMR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and gel permeation chromatography (GPC). The supported ionic liquid film on the surface of Pd/C catalyst can prevent the products from covering the hole of active carbon due to its chemical stability and weak coordination ability with metal ions, and thus efficiently improve the catalytic activity. The effects of different amounts of ionic liquid on the catalytic activity and reusability of the catalyst and the molecular weight of PK were discussed. When the usage of ionic liquid is 10wt% (0.1 g ionic liquid / 1 g active carbon carrier) and the theoretical content of Pd2+ is 5wt% (0.05 g Pd2+/ 1 g active carbon carrier), the highest catalytic activity 2 963.64 gSTCO/(gPd · h) is achieved with the molecular weight and polydispersity index of PK as M n = 9 684, M w = 13 452 and M w/M n = 1.389.

Removal of phenolic compounds from aqueous solutions by emulsion liquid membrane containing Ionic Liquid [BMIM]+[PF6]− in Tributyl phosphate

An experimental study on removal of phenolic compounds from aqueous solutions using Ionic Liquid Mixed Carrier (ILMC) containing 1-Butyl 3 Methylimidazolium Hexafluorophosphate [BMIM]+[PF6]− dissolved in Tributyl phosphate (TBP) in an Emulsion Liquid Membrane (ELM) was carried out. The effects of various operating parameters such as TBP Concentration, stripping reagent concentration, surfactant concentration, emulsification time, phase volume ratio, treat ratio, stirring speed, external phase pH and [BMIM]+[PF6]− concentration in TBP on removal of phenol has been experimentally investigated. It was found that addition of 0.02% (v/v) of [BMIM]+[PF6]− in membrane phase has enhanced the emulsion stability by 5 times and this was carried out using Rose Bengal dye to visualise the emulsion separation. An FTIR spectrum for TBP, ILMC and membrane phase before and after loading of phenol was generated to indicate their interactions and bonding. By selecting appropriate operating conditions, it was found to remove 99.5% of phenol and more than 90% of chlorophenols from aqueous solutions at the treat ratio of 3.