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Four different dicyanamide-based ionic liquids (ILs), [Cnmpy][DCA] (n = 4, 6, 8, and 10), were synthesized, characterized, and used to separate ethylbenzene from n-octane. Equilibrium data for the corresponding ternary systems were measured at 313.15 K under atmospheric pressure. A higher selectivity is observed for lower aromatic concentrations in the feed (20% max); this is a key factor in selecting a suitable IL. The distribution ratio and selectivity obtained in this work are comparable to those of commercial solvents. The nonrandom two-liquid model (NRTL) was successfully used to correlate the experimental tie-lines and to calculate the phase compositions of the ternary systems. Moreover, the antimicrobial activities of the ILs were evaluated by examining their 50% effective concentrations (EC50) using the standard microbroth dilution test against four human bacterial pathogens. 1-Butyl 3-methylpyridinium dicyanamide [C4mpy][DCA] was found as the most suitable IL among those investigated because of i...

This present study is dedicated to the synthesis, characterization and microbial toxicity assessment of phosphonium- and ammonium-based ionic liquids (ILs) bearing four different anions phenylalalinate (Phe), taurinate (Tau), hydroxide (OH), and acetate (Ac). The structures of the subsequent ILs were confirmed by 1H and 13C nuclear magnetic resonance (NMR). Physicochemical properties such as density, thermal stability, conductivity, surface tension, and refractive index were measured. Subsequently, the in vitro toxicity profiles of the ILs were determined for selected Gram-positive and Gram-negative bacteria in terms of inhibition zones (IZ), minimum inhibitory concentrations (MIC), and minimum bactericidal concentrations (MBC). The results showed that the ILs were in the range of “practically harmless” to “harmless”. The order of the same was OH > Ac > Tau > Phe, with phenylalalinate being the most toxic anion owing to its aromatic nature. With reference to the experimental results, the nature of the critical micellar concentrations and water octanol partitioning was discussed in the context of microbial toxicity. Hence, it was shown that anions, rather than cations, were the major contributors to toxicity.

Micron-sized vermiculite (VMT) clay was modified with 3-aminopropyltriethoxysilane (APTES) through sonication. The surface modification was proficient within 30 min of sonication relatively than long reflux times reported prior. A grafted mesoporous silica (GSIL) was synthesized through demineralization of the micron-sized VMT and further functionalized with APTES. The adsorbents were characterized by FTIR, TGA, XRD, and FE-SEM. The pore size distribution and surface area were determined using N 2 adsorption–desorption isotherms. The performance of the synthesized substances as adsorbents was evaluated by the removal of an Alizarin Red S (ARS), organic dye from aqueous solutions. The maximum sorption capacity was 18.2 mg/g for APTES grafted vermiculite and 59.8 mg/g for APTES grafted silica. The adsorbent dose, pH, temperature, dye concentration, and influence of contact time on the removal of ARS were investigated. The ARS adsorption increased with adsorbent dosage and reached a maximum of 0.8 mgmL−1 for both adsorbents. The experimental data were best fitted by the Langmuir isotherm model. The Kinetics of adsorption modeling confirmed that the ARS adsorption pursued a second-order model. The thermodynamic parameters evaluated from van’t Hoff’s model revealed a spontaneous endothermic adsorption process.

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Biodiesel production via esterification/transesterification reactions can be catalyzed by homogenous or heterogeneous catalysts. Development of heterogeneous catalysts for biodiesel production is highly advantageous due to the ease of product purification and of catalyst recyclability. In this current work, a novel acidic [DABCODBS][CF3SO3]2 dicationic ionic liquid (DIL) was used as heterogeneous catalyst to produce biodiesel using oleic acid as model oil. The esterification was conducted under ultrasonic irradiation (20 kHz) using a 14 mm ultrasonic horn transducer operated at various duty cycles. It was observed that the duty cycle, amplitude, methanol to oil molar ratio, catalyst amount and reaction temperature were the major factors that greatly impact the necessary reaction time to lead to a high yield of biodiesel. The reaction conditions were optimized with the aid of Response Surface Methodology (RSM) designed according to the Quadratic model of the Box Behnken method. The optimum conditions were found to be at catalyst amount of 0.64 mol%, methanol to oil ratio of 14.3:1, temperature of 59 °C, reaction time of 83 min and amplitude of 60% in continuous mode. The results showed that the oleic acid was successfully converted into esters with conversion value of 93.20% together with significant reduction of reaction time from 7 h (using mechanical stirring) to 83 min (using ultrasonication). The results also showed that the acidic DIL catalyst we designed purposely was efficient to catalyze the ultrasonic-assisted esterification yielding high conversion of oleic acid to methyl oleate on short times. The DIL was also recycled and reused for at least five times without significant reduction in performance. Overall, the procedure offers advantages including short reaction time, good yield, operational simplicity and environmentally benign characteristics.

In this work the synthesis of five new Bronsted acidic ionic liquids (BAILs) bearing same anion (camphorsulfonate) but different cations; 3-(3-sulfopropyl)-imidazolium, 1-methyl-3-(3-sulfopropyl)-imidazolium, 1-methyl-3-(4-sulfobutyl)-imidazolium, 1-ethyl-3-(3-sulfopropyl)-imidazolium, 1-butyl-3-(3-sulfopropyl)-imidazolium) were synthesized and characterized. The characterization of BAILs was carried out using NMR, FTIR and elemental analysis (CHNS). The thermophysical properties of these ILs such as density, refractive index, viscosity and thermal stability were analyzed in wide temperature window. Furthermore, the effect of alkyl chain length of cations on thermophysical properties was well studied. The experimental values of density were further used to calculate other significant properties such as molar volume, standard molar entropy, lattice energy and thermal expansion coefficients. The Bronsted acidities of investigated ILs were determined using Hammett method. Furthermore, COSMO-RS study was performed to determine δ-surface, and δ-profile of the studied ILs.

In this study, four new protic ionic liquids (PILs), possessing camphorsulfonate anion with four different cations, 2-methyl-3-(3-sulfopropyl)-imidazolium (7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methanesulfonate [2MeimPS][CS], 2-ethyl-3-(3-sulfopropyl)-imidazolium (7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methanesulfonate [2EteimPS][CS], 2-phenyl-3-(3-sulfopropyl)-imidazolium (7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methanesulfonate [2PhimPS][CS] and 3-(3-sulfopropyl)-benzimidazolium (7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methanesulfonate [BnzimPS][CS] were synthesized and characterized. The effect of alkyl and aromatic substitution on the imidazolium cation was investigated in terms of fluctuations in density, viscosity and thermal degradation of ILs. The density and viscosity were determined within a broad temperature range and measured values of density were used to calculate molar volume, standard molar entropy, lattice energy and thermal expansion coefficients. The refractive indices were measured with an ATAGO refractrometer (RX-5000a) within the temperature range of 288.15–333.15 K. The studied ILs exhibited strong Bronsted acidities as determined by Hammett method. Three human pathogenic bacteria i.e. Escherichia coli E149 (EC), Staphlylococcus aureus S244 (SA) and Aeromonas hydrophilla A97 (AH), were deployed to investigate the toxicity behaviour of studied ILs and their 50% effective concentrations (EC50) were found in comparison with the least toxic imidazolium-based ILs. COSMO-RS was used to determine δ-surface, δ-potential and δ-profile of the investigated ILs.

Protic ionic liquids (ILs) with seven-membered azepanium cation were synthesized and characterized. The molecular structure of the synthesized ILs was confirmed using 1H NMR and 13C NMR spectroscopy. In one hand, sulfonic acid ( SO3H) group was tethered to the azepanium moiety combined with HSPO4 or H2PO4−anion and on the other hand azepanium based alkyl sulfate ILs were synthesized by reacting azepane with corresponding dialkyl sulfates. Thermo-physical properties (density, viscosity, glass transition temperature, thermal decomposition temperature) of the synthesized ILs were measured. All the studied ILs showed good thermal stability. From the viscosity and density data of alkyl sulfate ILs, the volumetric properties such as molar volume, lattice energy and standard molar entropy were calculated. COSMO-RS was used to predict hydrogen bonding energy, interaction energy, Van der Waals energy and H-bond accepting and H-bond donating nature of these pure ILs. Activity coefficient values have also predicted for these ILs with cellulose.

Covalent triazine-based organic polymers (CTPs), a sub class of covalent organic polymers (COPs), are promising materials for CO2 adsorption although the impact of their dimensionality on the trapping process is not well-understood. Two different molecular geometries of phenyl-based diamine linkers, planar p-phenylenediamine and angular 1,2-diphenylethylenediamine, were subsequently chosen to afford 2 CTPs (ACTP-1 and ACTP-2) via catalyst-free polycondensation to acquire deeper fundamental understanding of the effect of their dimensionality on the adsorption efficiency. Although ACTP-2, with non-planar building blocks, showed a significant improvement in the porosity of its network in comparison with the planar structure polymer ACTP-1, it also displayed pore size distribution that is twice as large. Furthermore, the presence of an alkyl chain linking the triazine units in ACTP-2 yielded a semi-crystalline polymer. At low pressure (up to 1 bar) and 298 K, ACTP-1 adsorbed significantly higher amount of CO2 (0.65 mmol g−1), implying that a planar building block is preferable to locate CO2 moieties. On the contrary, steric hindrance due to the bulkiness of the aromatic ring restricted the interaction between CO2 and amine functional group in ACTP-2. Hysteretic sorption of CO2 was observed in ACTP-2, indicating the flexibility of the polymer due to the pressure change effect. Isosteric heats for ACTP-1 and ACTP-2 were 35 kJ mol−1 and 22 kJ mol−1, respectively. An increase in the C/N ratio of the triazine polymer resulted in higher affinity towards CO2 that that towards N2. For ACTP-1, the CO2/N2 selectivity of CO2 : N2 in the ratio of 15 : 85 was 43 at 298 K and 1 bar, and it was superior than those of most of the covalent triazine frameworks (CTFs) reported in recent literature at low pressure.

Highlights: • Addition of ionic liquid has impacts acoustic cavitation by increasing its efficiency. • Ionic liquid alkyl chain length effects the viscosity & surface tension of water. • Presence of ionic liquid may extend the life of radicals formed from sonolysis effect., This study investigates the potential of using small amounts of ionic liquids (IL) to enhance ultrasound-assisted extraction of lipids content from green microalgae. Three imidazolium-based ILs (butyl, octyl and dodecyl), each of them with two anions (bromide and acetate) were tested as additives. Viscosity and surface tension of the ILs aqueous mixtures were analyzed to determine the influence of ILs’ anions and alkyl chain length, whereas KI dosimetry experiments were used as an indicator of radicals formation. A key finding suggests that the small addition of ILs improves the ultrasonication either by enhancing the viscosity and reducing the water surface tension, leading to a more powerful acoustic cavitation process or by increasing HO° production likely to oxidize the microalgae cells membranes, and consequently disrupting them on a more efficient manner. KI dosimetry also revealed that long ILs alkyl chain is detrimental. This experimental observation is confirmed thus strengthened as the yield of extracted lipids from green microalgae has shown an incremental trend when the IL concentration also increased. These hypotheses are currently under investigation to spot detailed impact of ILs on cavitation process.

Background: Sulfonated polyimides (SPIs) are considered as the promising alternatives to Nafion as membrane materials for the polymer electrolyte membrane (PEM). They generally exhibit high ionic conductivity, good mechanical properties, excellent thermal and chemical stabilities. The six-membered ring, naphthalenic anhydride-based SPIs, not only exhibit superior chemical and thermo-oxidative stabilities but are also more resistant to hydrolysis than their five-membered phthalic anhydride-based SPIs. The composites based on napthalenic polyimides are also significantly stable in high temperature environment and show better stability to hydrolysis. Incorporation of inorganic fillers into organic polymers has gained tremendous attention and these new materials are called organic-inorganic hybrids. Few patents related to the synthesis and performance PEM materials have been reviewed and cited. Keeping in view the importance of sulfonated polyimide based nanocomposites as potential membrane materials for PEM in fuel cell, we have synthesized SPIs clay based nanocomposite as potential membrane material. The objective of this work was to synthesize clay based SPIs thin films which could be used as membrane materials in PEM fuel cell for energy applications. Methods/Experimental: At the first step the nanometric sheets of vermiculite clay prepared via sonication was surface modified by grafting 3-APTES. Then the SPI was synthesized via one-step high temperature direct imidization method, which serve as a matrix material. The organo modified VMT was dispersed via sonication in the SPI matrix. Four different sets of organic-inorganic nanocomposite membranes thin films, having VMT contents in the range of 1 to 7 wt. were prepared by casting, curing and acidification route. Results: The synthesis of SPIs clay based thin films were carried out at three different steps and fully characterized. The synthesis of SPIs and SPIs clay based thin films were analyzed via different analytical techniques. The XRD analysis tells the successful dispersion of clay in SPI matrix. Different physiochemical tests were conducted for the analysis of these membranes such as water uptake, hydrolytic stability, ion exchange capacity (IEC), dimensional changes and oxidative stability, to check their suitability as membrane materials for PEM. The proton conductivity of these membranes were measured via impedance spectroscopy which discloses three different active regions responsible for proton conduction. The activation energies of the membranes were higher at lower temperature and reaches to 8.2 kJ/mol at higher temperature (90°C). Conclusion: The synthesis of sulfonated polyimide/clay (SPI/clay) based organic-inorganic nanocomposite membranes were achieved successfully. The membrane display good hydrolytic, thermal and oxidative stability at elevated temperature. The proton conductivity of the membrane display an increase together with the frequency but decreases with temperature. Therefore some more efforts are required to achieve high degree of functionalization of both organic and inorganic components, for the �future� PEMs to avoid deterioration and to get improved performance. © 2016 Bentham Science Publishers.

In this work, three novel imidazolium-based ionic liquids containing aromatic group in the cation combined with bis(trifluoromethylsulfonyl)imide anion were synthesized and characterized. Their thermophysical properties namely, density, viscosity, thermal decomposition, glass transition, and heat capacity were measured at various temperatures and atmospheric pressure. In addition, physicochemical properties such as molar volume (Vm) and crystal energy (UPOT) were also determined from the obtained density data. Novel group contribution parameters were obtained using Gardas and Coutinho model aiming at providing simple method to predict density and viscosity of ionic liquids.

The adsorption isotherms of two new ionic liquids (4-tert-butyl-1-propylpyridinium bromide: IL1 and (4-ter-butyl-1-(2 carboxyethyl) pyridinium bromide: IL2) and ibuprofen (2-[4-(2-methylpropyl) phenyl] propanoic acid: IBP) on an activated carbon cloth were studied at 286, 298 and 313 K. Experimental adsorption isotherms were simulated by a single energy monolayer model using statistical physics, allowing to determine the number of molecules per site ( n ), the density of receptor sites ( N M ) and the concentration at half saturation ( c 1/2 ). Simulation results suggested that two adsorbates were docked per receptor sites of the activated carbon cloth surface. As a function of temperature, the study of the monolayer adsorbed quantity has indicated that the adsorption process is exothermic. The magnitudes of the estimated adsorption energies have indicated that IBP and ILs have been physisorbed on the adsorbent. The conductor-like screening model for real solvents (COSMO-RS) was applied to calculate three specific interaction energies of ILs and IBP with a graphene layer, i.e., the electrostatic misfit energy (E MF ), the hydrogen-bonding energy (E HB ) and the Van der Waals energy (E vdW ). The COSMO-RS model has proved that the interaction of all the three studied adsorbates with a graphene layer mainly depends on the Van der Waals contribution. The highest interaction energies of IL2 and IBP with the carbon surface have been explained by the additional contribution of hydrogen bond attributed to the presence of a carboxyl group on these molecules.

Ionic liquids (ILs) are molten salts that possess low melting points and wide solvation properties. ILs attracted the attention of the academic and industrial professionals due remarkable properties such as low vapor pressure and thermal stability which make them more environmentally friendly as they can replace volatile organic solvents (VOCs) in many organic reactions. This has brought attention to broaden this research area to overcome the harmful emissions from VOCs in industry. Pyridinium ILs have a wide range of applications in various domains such as material sciences, organic and bioorganic syntheses, biotechnologies, nanotechnology and Enhanced Oil Recovery (EOR). However, available toxicity data in literature is yet scarce and hampers a large scale development. In this study, 18 synthesized ILs were tested against guppy fish and four bacterial strains. Two gram negative bacteria: Salmonella enterica, Vibrio cholera and two gram positive bacteria: Listeria monocytogenes, Staphylococcus aureus were chosen to represent each category of bacteria . Fish test was conducted using OECD guidelines and the “96-well plate” procedure was adopted for the bacterial test using (CLSI M100-S24). Results showed that long alkyl chain length ILs showed higher toxicity than short alkyl chain analogs on all the targeted strains. The highest toxic effect exhibited by pyridinium ILs towards guppy fish was moderately toxic and the rest varied between relatively harmless and practically nontoxic. The highest antibacterial effect indicated slightly toxic effect towards Staphylococcus aureus obtaining EC 50 = 19.3 mg/L. In most cases, pyridinium ILs indicated relatively harmless and practically harmless effects towards bacteria after comparing the EC 50 values obtained with Passino and Smith 1987 hazard ranking.

Polyamine triazine based Covalent Organic Polymer (COP) was synthesized using catalyst free polycondensation method, called Covalent Diamino Polymer (CDAP). 1,3-diaminopropane was selected as the organic linker and the CO 2 adsorption capacity was studied. CDAP was characterized with Fourier Transform Infra-red spectroscopy (FTIR) and N 2 adsorption desorption measurement. A comparison of the characteristics and CO 2 adsorption capacity was made between COP-1 and CDAP. This study found that the structure of organic linkers greatly influences the properties of organic polymer as well as the CO 2 uptake capability.

Catalysis is important in various applications of organic chemistry and its output product control for stereoselective compounds is outrageous. Establishment of experimental facts of stereoselective compounds from catalysis and their validation using theoretical evidences is the key to understand various mechanisms of optically active compounds. A family of new ionic liquids (ILs) with various imidazolium cations and camphorsulfonate anion as environmentally benign liquid salts have been synthesized and deployed for catalysis of β-amino carbonyl compounds. The products were formed using ILs as a homogeneous catalyst with excellent product yield and diastereoselectivity. The effect of counter ions, Hammett acidity and viscosity of ILs along with solvent and temperature are explored in terms of reaction kinetics and product yields. Density functional theory (DFT) was used to investigate thermodynamical study of mechanistic pathway of the reaction. The DFT calculations predicted that the catalysis mechanism involved both counterions of the IL. Moreover, it is evidenced that the syn-pathway required lower activation energy while anti-pathway led to thermodynamically stable product. This study explores new avenues for using ILs as potential homogeneous catalysts for the production of stereoselective species.

The physicochemical properties including density, viscosity and refractive index of five ionic liquids (ILs) consisting of 2-acrylamido-2-methylpropanesulfonate [AMPS] as anion source with ammonium-based cations (tetrabutylammonium [TBA], tetrapropylammonium [TPA] and tetraethylammonium [TEA], tetramethylammonium [TMA] and (vinylbenzyl)trimethylammonium [vbn]) were measured and influence of these properties upon CO2 sorption was investigated. The viscosity and density measurements were taken at atmospheric pressure within the temperature range of (293.15–363.15) K, whereas refractive indexes were determined within (288.15–333.15) K. An increase in the side-carbon chain length of ammonium-based cations resulted in decreased density with a corresponding increase in viscosity and refractive index. Among the studied ILs, [TBA][AMPS] gave the highest viscosity and least density over the whole range of temperature and a higher CO2 sorption of 0.51 mol fraction at 298.15 K and 1 MPa was observed showing dependency of CO2 solubility on the thermophysical properties of studied ILs. Moreover, among investigated ILs, molar volume of [TBA][AMPS] was found to be largest (433.3729 cm3mol-1), which resulted in the higher amount of CO2 sorption in comparison to other investigated ILs. Also, Henry's constant of 1.51 MPa was found for [TBA][AMPS] which was 10.9, 33.4, 44.3 and 24.8% less than [TPA][AMPS], [TEA][AMPS], [TMA][AMPS] and [vbn][AMPS], respectively. The current work offers an in depth study to understand structure-activity relation between physicochemical properties and CO2 solubility of investigated ILs and explores the ways for enhanced CO2 sorption.

The antibacterial assay and Bronsted acidities of seven protic ILs bearing 1-ethyl-3-methyl imidazolium ([emim]), 1-butyl-3-methyl imidazolium ([bmim]), 1-benzyl-3-methyl imidazolium ([bnmim]), 1-butyl-1methyl pyrrolidinium ([bmpyr]), N-butyl pyridinium ([bpyn]), morpholinium ([mrph]) and (vinylbenzyl)trimethylammonium ([vbn]), as cation sources paired with 2-acrylamido-2- methyl-1-propanesulfonate ([AMPS]) anion were investigated. Escherichia coli E149 (EC), Aeromonas hydrophilla A97 (AH) and Staphlylococcus aureus S244 (SA) were used for toxicity determination of prepared ILs. Molecular docking studies were carried out for confirmation of binding interactions of molecules with the target complex. A good correlation was observed between experimental and theoretical results. The Hammett acidity functions of studied ILs were calculated from Hammett equation. Moreover, COSMO-RS computational study was done to study the cationic structural variations in studied ILs on the interaction of ILs with CO2. The current work offers a thoughtful understanding of acidity, toxicity and CO2 sorption of AMPS-based ILs to unfold the routes for their further synthetic, biological and environmental applications as promising applicants with multidimensional properties.

A series of five AMPS-based new ionic liquids (ILs) paired with different cations (thiazolium, ammonium, morpholinium, pyrrolidinium and iminium) has been synthesized and characterized by spectroscopic analysis. 3-Benzyl-5-(2-hydroxyethyl)-4-thiazolium [bnthia], (vinylbenzyl)trimethylammonium [vbn], morpholinium [mrph], 1-butyl-1-methylpyrrolidinium [pyrli] and (chloromethylene)dimethyl iminium [diMeimi] were used as cation moieties. DNA binding interactions, antioxidant assay and DFT studies have further been performed. The DNA binding analysis revealed that all the investigated ILs were able to electrostatically interact with DNA. None of the IL could intercalate into DNA. The DFT calculations predicted that [bnthia][AMPS] and [vbn][AMPS] may stabilize incoming electrons in their LUMO orbitals and can be radical scavenger. This prediction was supported by antioxidant assay using UV–Vis spectroscopy and cyclic voltammetry where DPPH radical scavenging by [bnthia][AMPS] and [vbn][AMPS] confirmed the DFT prediction. However, rest of the ILs did not scavenge DPPH free radicals.

Most of the newly discovered gas reservoir has high CO2 content (up to 70%), thus pose critical challenges to gas separation process due to the limitation of current acceptable technology. Recent report on COP-1 showed its potential as sorbent for CO2 capture due to its high adsorption capacity, low cost sorbent with good water resistance. However, scarce data on the potential of COP-1 and its selectivity for CO2/CH4 adsorbent for high pressure operation were reported. In this study, the adsorption isotherms were gravimetrically measured using magnetic suspension balance (MSB) within the range of 50–100 bar, at isothermal temperatures of 298, 318, 328 and 338 K. Langmuir and Sips isotherm models were correlated to the adsorption equilibrium data at critical and supercritical conditions. The ideal adsorption selectivities for CO2/CH4 separation were also predicted using Ideal Adsorbed Solution Theory (IAST). The ideal selectivity obtained (∼22) shows good separation performance for CO2 from CH4 onto COP-1. Furthermore, isosteric heats of adsorption calculated from Clausius-Clapeyron equation reveals that physisorption is the dominant factor for the interaction between adsorbates and surface of COP-1. Results also showed that the isostearic heat of COP-1 is a strong function of temperature and adsorbed amount. Nevertheless, the adsorption behaviour of COP-1 found in this work gives a good indication on the utilization of COP in CO2/CH4 separation for unexploited natural gas reservoir with high CO2 content.

The inherent chemical complexity of biomass renders it as a very attractive source to be recycled and converted into value-added chemicals representing perhaps the largest challenge facing the twenty-first century. To face this issue, over the last three decades, significant effort has been spent for the development of environmentally friendly protocols by means of non-conventional energy sources such as ultrasound (US) and hydrodynamic cavitation (HC) for biomass pretreatment and subsequent chemical transformations.

Acoustic cavitation invariably combines chemical and mechanical effects that stem from bubble collapse in liquids. Strategies to harness preferentially the role of mechanochemistry in sonochemistry have been invented and developed in recent years, demonstrating enormous versatility from synthesis and catalysis to biology and analytical monitoring. Most cases involve polymers containing weak bonds that can be fragmented by sonication. The effects are dependent largely on both the nature of substrates and the strength of cavitational collapse.

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The thermophysical properties such as density, refractive index, and viscosity of five aprotic ILs bearing imidazolium (1-ethyl-3-methylimidazolium [emim], 1-butyl-3-methylimidazolium [bmim], 1-benzyl-3-methylimidazolium [bnmim]), pyrrolidinium (1-butyl-1methylpyrrolidinium [bmpyr]), and pyridinium (N-butylpyridinium [bpyn]) cations with 2-acryloamido-2-methylpropanesulfonate [AMPS] anion were studied, and their effect on CO2 solubility was explored. The density and viscosity were determined within the temperature range of (293.15 to 363.15) K at atmospheric pressure, while refractive indices were measured within the temperature range of (288.15 to 333.15) K. Among imidazolium cations, increasing the side chain length resulted in increased refractive index and viscosity with a corresponding decrease in density. In the presented ILs, [emim][AMPS] showed the highest density and least viscosity over the entire temperature range and an enhanced CO2 dissolution of 0.40 mole fraction at 1 MPa was observed at 29...

Ionic liquids (ILs) are considered as emergent pollutants as their synthesis and further use at a large scale might generate environmental problems. The adsorption on activated carbons represents one of the most effective methods to remove ionic liquids and other micropollutants from wastewater. In this work, the adsorption properties on an activated carbon cloth of two pyridinium ionic liquids (4-tert-butyl-1-propylpyridinium bromide (IL1) and 4-tert-butyl-1-(2-carboxyethyl)pyridinium bromide (IL2)) newly synthesized, were compared with the ones of ibuprofen. The adsorption kinetics and isotherms were studied at pH 3 and 7.5. The adsorption thermodynamic parameters calculated from the isotherms indicate an exothermic process, typical of physisorption. The adsorption kinetics of a mixture of the molecules show a competition between ibuprofen and IL2. The location of each adsorbed ionic liquid and ibuprofen into the porosity of the activated carbon cloth was determined from N2 (at 77 K) and CO2 adsorption isotherms (at 273 K). The purification process of an effluent containing the ionic liquids and the ibuprofen in mixture or in single solute could be workable by adsorption on an activated cloth. Keywords: Adsorption, Kinetics, Isotherms, Activated carbon cloth, Ibuprofen, Ionic liquid

A new group of low viscosity hydrophobic trioctylammonium-based protic ionic liquids (PILs) with 2-naphthoate, 4-tert-butylbenzoate, 2-hexyldecanoate, and 4-phenylbutanoate anions were synthesized. All the synthesized PILs were liquids at room temperature. The PILs were characterized using nuclear magnetic resonance, elemental analysis, and Fourier transform infrared spectroscopy. Thermogravimetric analysis was conducted to determine the decomposition temperature of the PILs. The PILs were then subjected to thermophysical properties study where their densities, viscosities, refractive indices, and surface tensions were measured within the temperature range of 298.15 to 363.15 K at atmospheric pressure and correlated with established empirical equations. Other thermophysical properties such as molar volume, standard entropy, and lattice potential energy were determined using the measured density data whilst the surface excess energy and entropy were estimated using the measured surface tension data.

Glassy carbon particles (millimetric or micrometric sizes) dispersions in water were treated by ultrasound at 20kHz, either in a cylindrical reactor, or in a "Rosette" type reactor, for various time lengths ranging from 3h to 10h. Further separations sedimentation allowed obtaining few nanoparticles of glassy carbon in the supernatant (diameter

The thermal degradation of two ionic liquids (ILs) was investigated using thermogravimetric analysis (TG) to establish a relationship between the thermokinetics and thermal stability. N-butyl, N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [BMPyrro][NTf2] and N-octyl, N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide[OMPyrro][NTf2] were subjected to thermogravimetric analysis at varying heating rates of 5, 10 and 20 °C min−1 in the temperature range of 50–600 °C. The data obtained were analysed for thermokinetics using Ozawa, Kissinger and Starink methods using differential thermogravimetric (DTG) techniques, and Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS) and Starink methods using TG techniques. The results produced very high regression coefficients (R 2 ) values around 0.996, which exhibited that they were best fitted by the kinetics equations. The average calculated activation energy (E a) of [BMPyrro][NTf2] using FWO, KAS and Starink methods was 128.6, 123.6 and 124 kJ mol−1, respectively, and 113.7, 107.8 and 108.2 kJ mol−1, respectively, for [OMPyrro][NTf2] using same empirical methods. This emphasizes that the activation energy is strongly related to the length of the side alkyl chain of a given IL. In other words, the longer the side alkyl chain, the lower the activation energy. The E a trends with degree of conversion (α) suggest that a single mechanism without formation of intermediates or short-life intermediates was followed by the pyrolysis kinetics. This study introduced thermokinetics as a tool to study the thermal stability of ionic liquids.

Catalytic conversion of starch-based industrial waste into sugars was investigated using a simultaneous microwave/ultrasound-assisted procedure. The results were compared with single microwave and ultrasound irradiations to determine the eventual synergetic effects generated by the combined technologies. In heterogeneous systems, microwave irradiation enforces heat transfer, while ultrasound irradiation imposes the intensive mass transfer at the interfaces. Two hours of combined irradiation of potato starch (employed as a reference) at 60 °C in sulfuric acid revealed the existence of a glucose selectivity. In a result that was hitherto never achieved, 46% of this industrial waste was converted into reducing sugars in identical conditions.

The viability of using ionic liquids (ILs) as extractive solvents to remove naphthalene (aromatics) and dibenzothiophene (DBT; Sulfur) from base oil by liquid-liquid extraction was investigated. The experiments were designed using Response Surface Methodology (RSM) with 1-butyl-3-methylpyridinium dicyanamide [BMPY][DCA], 1-butyl-3-methylimidazolium dicyanamide [BMIM][DCA], 1-butyl-3-methylimidazolium thiocyanate [BMIM][SCN] and 1-butyl-3-methylimidazolium dimethylphosphate [BMIM][DMP] ILs. The sulfur compound and aromatics were analyzed using Total Sulphur analyzer and High Performance Liquid Chromatography (HPLC) with high coefficient of determination i.e. R2 values of 0.964 and 0.997 respectively. The effects of different ILs, temperatures, and ILs to oil mass ratio (IL:Oil) were optimized.[BMPY][DCA] appeared as the most promising medium with 94.3% of dibenzothiophene and 83.1% of naphthalene removal after a single extraction step. The aromatics and sulfur removal efficiency of [BMPY][DCA] IL was 54.3%, 78.3% and 82.9%, 93.8% at IL:Oil ratios of 0.4 and 1.8, respectively. An increase in temperature did not improve the extraction efficiency, but a slight decrease was noted.Results emphasized that extraction of aromatics and sulfur compoundsfrom base oil can be achieved successfully using selected ionic liquids.

Ionic liquids (ILs) are often touted as potential ‘green’ substitutes for volatile organic compounds in process chemistry. However, their often high solubility in water limits their applications since discharge of spent ILs into natural water bodies may have significant detrimental eco-toxicological consequences for aquatic organisms. This is especially true for most imidazolium and pyrdinium based ILs which have been proven as toxic to aquatic life organisms. The challenge is therefore to synthesize ILs which exhibit inherently low aquatic toxicity. In the present work, five choline based ILs pairing five different amino acid anions [Cho][AA] have been synthesized and characterized. Their thermal stability, density, viscosity and thermal expansion coefficient were reported. The toxicity behavior of a synthesized ILs were investigated on guppy fish ( Poecilia reticulate ) and three microbial species. Fish acute toxicity test reveal that the studied ILs could be classified as non-toxic while their 50% effective concentrations (EC 50 ) were found to be comparable to the least toxic imidazolium-based ILs.

The liquid-liquid extraction of Methylene Blue (MB) from aqueous solution was undertaken with 5 hydrophobic ionic liquids (ILs) based on bis(trifluoromethylsulfonyl)imide anion [NTf2] for comparison purpose where three of them were of commercial origin, 1-butyl-3-methyl imidazolium [BMIm], 1-hexyl-3-methylimidazolium [HMIm] and 1-octyl-3-methylimidazolium [OMIm] cations and the two other were purposely designed for this work, 1-hexyl-2-phenylimidazolium [HPhIm], and 1-benzyl-3-methyl-imidazolium [BnMIm]. Several parameters such as the place and nature of the aromatic ring, the length of the side alkyl chain and the ability to form hydrogen bonding were investigated to evaluate their impact on extraction performances. Results show that the incorporation of the functional group (aromatic group) not only led to excellent results of dye removal compared to commercially available ones but allowed easier recovery and subsequent reuse of the functionalized ILs. Conductor like Screening Model for Real Solvents (COSMO-RS) calculations were also performed to see the structural variations of the ILs their extraction capabilities of MB from water. The finding of this study may assist in reducing the pollution of wastewater from dye industries.

Choline-Amino acid based ionic liquids (AAIL) have sparked recent interest throughout the scientific community due to their allegedly low cost and natural origin. They are considered as a potential “green” solvent to replace conventional volatile organic solvents. However, much is still scarce on their (AAILs) microbial toxicity and biodegradability. This study reports the synthesis of ten AAILs with cholinium cation and variable anions derived from amino acids. Their microbial biocompatibility to gram-positive (Bacillus licheniformis and Staphylococcus aureus) and gram-negative (Pseudomonas aeruginosa and Vibrio cholerae) bacteria and biodegradability by industrial sewage water were analyzed. All the tested AAILs were reported to have EC50 values in the range of 160-1120 mg/L which is deemed “practically harmless” based on hazard rankings. The toxicity trend was seen to reduce as the molecular weight of the anion decreased. The level of mineralization of AAILs through anaerobic microbial breakdown was found to be a factor of anion and its functional group in all the cases. They resulted to over 60% biodegradation in 28 days (readily biodegradable).

Dicationic ionic liquids are attractive new group of ionic liquids that acquire higher melting point, wider liquid range and better thermal stability. However, the exploration made on the utilization of these dicationic ionic liquids in any application is still limited. To the best of the author’s knowledge, this is the first review article that discuss about this new type of ionic liquids. This review describes about ionic liquids in general and gives a survey on the latest developments and progress concerning dicationic ionic liquids, from their classifications and properties to their employment in many applications.

Butylpyridinium thiocyanate [BuPyr]SCN ionic liquid was synthesized by metathesis and characterized. NMR spectrum has shown the [BuPyr] cation while FTIR has shown the SCN anion peak which confirms the structure of the synthesized ionic liquid. The ionic liquid was impregnated on activated carbon in order to enhance performance of sulfur dioxide adsorption compared to the non-impregnated raw activated carbon. Two types of activated carbons were used; activated carbon cylindrical granules and cloth. Different percentages of ionic liquid loading (1%, 10% and 20%) were applied. The capacity of the adsorbent for treatment of 10 ppm and 50 ppm SO2 was determined by breakthrough curve analysis whereby optimum breakthrough time was obtained. [BuPyr]SCN impregnated on activated carbon cloth have shown higher adsorption performance.

International audience; Four new ionic liquids (ILs) based on 1-(2-hydroxyethyl-3-methylimidazolium) cation with glycinate, serinate, alaninate, and prolinate amino acid anions have been synthesized, and their thermo-physical properties (density, viscosity, surface tension, and heat capacity) were measured. Data were described using empirical expressions to determine other physical-chemical properties, such as molecular volume, standard molar entropy, and lattice energy. Moreover, acute toxicity tests toward Scenedesmus quadricauda (green algae) and Vibrio fischeri have been conducted. The high values obtained for the 50% effective concentration (EC50) indicated that these new ionic liquids can be considered eco-friendly. (C) 2015 Elsevier B.V. All rights reserved.

Tuning the characteristics of solvents to fit industrial requirements has currently become a major interest in both academic and industrial communities, notably in the field of room temperature ionic liquids (RTILs), which are considered one of the most promising green alternatives to molecular organic solvents. In this work, several sets of imidazolium-based ionic liquids were synthesized, and their toxicities were assessed towards four human pathogens bacteria to investigate how tunability can affect this characteristic. Additionally, the toxicity of particular RTILs bearing an amino acid anion was introduced in this work. EC50 values (50% effective concentration) were established, and significant variations were observed; although all studied ILs displayed an imidazolium moiety, the toxicity values were found to vary between 0.05 mM for the most toxic to 85.57 mM for the least toxic. Linear quantitative structure activity relationship models were then developed using the charge density distribution (σ-profiles) as molecular descriptors, which can yield accuracies as high as 95%.

A novel aromatic polyamine covalent triazine-based polymer, CPDA was obtained by the polymerization of amino group (1,4-phenylenediamine) and cyanuric chloride. CPDA was characterized with Fourier Transform Infra-red spectroscopy (FTIR) and the thermal behaviour was studied with thermal gravimetric analysis (TGA) and derivative thermal analysis (DTA). A comparison study for CO2 adsorption capacity on covalent organic polymer 1 (COP-1) and CPDA was performed. By introducing the aromatic ring into the nitrogen fertile triazine based system, the thermal stability of the network is enhanced. Polymer structure containing secondary amine functionality was observed in this study. Besides, the suggested chemical pathway is another approach to synthesis of covalent organic materials using economic monomers and absence of expensive catalyst.

An advanced dual frequency ultrasonic coaxial reactor enabling simultaneously low and high frequencies irradiating in the same direction was developed to focus both mechanical and chemical effects on a concentrated area. The prototype was straightforward employed for the conversion of a starch-based industrial waste into sugars.

Probe-type ultrasonication has been employed for surfactant-aided solubilization, or individualization, of single-walled carbon nanotubes (SWNTs). The resulting solution can be used not only for spectroscopic analyses such as absorption, photoluminescence, and circular dichroism, but also for separation by density gradient ultracentrifugation, dielectrophoresis, chromatography, and polymer wrapping. In spite of its importance, the sonochemical processing of SWNTs has not been considered seriously. Herein, we report on a more efficient cooling cell for probe-type ultrasonication. As compared with a conventional cylindrical cell, the concentration of the SWNTs solubilized in water was found to be almost double in a rosette cooling cell after ultracentrifugation. The efficiency of a rosette cell can be attributed to the higher efficiency in circulation and cooling of the SWNT dispersion as well as enhancement of the cavitation process.

Three 1-(2-hydroxyethyl)-3-alkylimidazolium chloride room temperature ionic liquids (ILs) [2OHimC(n)][Cl]; (n=0, 1, 4) have been synthesized from the appropriate imidazole precursors and characterized by IR and NMR spectroscopies and elemental analysis. Their anti-microbial activities were investigated using the well-diffusion method. The viabilities of Escherichia coli, Aeromonas hydrophila, Listeria monocytogenes and Salmonella enterica as a function of IL concentrations were studied. The minimal inhibitory concentrations (MICs) and EC₅₀ values for the present ILs were within the concentration range from 60 to 125 mM and 23 to 73 mM. The anti-microbial potencies of the present ILs were compared to a standard antibiotic, gentamicin. The finding affords additional perspective on the level of ILs toxicity to aquatic lifeforms and yet, this characteristic can be readily harnessed to detect microbial growth and activity.

Precipitation and liquid–liquid extraction of PtX62− (X = Cl−, Br−, SCN−) in acidified aqueous solutions ranging from 0.1 M to 9 M HBr or 11 M of HCl have been studied using water-soluble or hydrophobic ionic liquids. Divalent hexachloroplatinate(IV) anions appear to be extracted much less efficiently than tetrachloroaurate(III) complexes. At a concentration of 11 M HCl, values of 15 and 800 for the distribution coefficients of PtCl62− and PtBr62− in [OMIM][NTf2] have been obtained accordingly. The presence of a labile hydrogen on the imidazolium ring has been found to play a specific role in the extraction of platinum(IV) complexes in concentrated HCl or HBr. Pt(SCN)62− appears to be very efficiently extracted at pH 1 using [OMIM][NTf2], exhibiting a distribution coefficient of 6150. Finally, two methods for quantitative separation of gold and platinum in water using in each method two extraction steps have been proposed. The back extraction of platinum(IV) during the second separation process was also discussed.

In this exploratory work, the comparison of the utilisation of different non-conventional technologies (ultrasound and microwave irradiations) for the depolymerisation of a complex industrial starch-based waste into reducing sugars was investigated. Reducing sugars could then be converted into higher value-added compounds such as higher alcohols. The experiments were performed on three different starting materials named as ‘Potato flour’, ‘Wet potato sludge’ and ‘Dry potato sludge’. The conversion of ‘Potato flour’ into reducing sugars reached in acidic conditions 61% within an hour under microwave irradiation, 70% and 84% within 120 min under low and high frequency ultrasonic irradiation, respectively.

International audience; Five first generation ionic liquids (RTILs : BMImCl, OMImCl, AMImCl, BPyBr and OPyBr) were intercalated into the layered structure of a Na-montmorillonite by dispersion in aqueous solutions ([RTIL] ⩽ 20 mmol.L-1). For all ionic liquids, the intercalation expanded the spacing of the silicate layers, as measured by X-ray diffraction. FTIR, thermogravimetric analyses and sodium titrations of the solutions after intercalation proved the adsorption of the RTILs through a cation exchange mechanism. Adsorption isotherms, done at pH = 7 and at 25°C, displayed that the maximum adsorption capacity of the substrates was closely linked to the nature of the organic cation and the length of the alkyl chain (BPyBr > OPyBr ∼ AMImCl ∼ BMImCl > OMImCl). For the five RTILs, calculated parameters obtained from the adsorption isotherms studied at 3 temperatures (25°C, 40°C and 55°C) concluded to an endothermic and spontaneous adsorption reaction.

The Molybdate-catalyzed bromination of various aromatic compounds in the presence of KBr/H 2 O 2 in an aqueous/chloroform biphasic system occurred under ultrasonic irradiation, whereas the reaction did not take place under conventional mechanical stirring (1400 rpm). The sonochemical activation was found to be of secondary effect, attributed to lowering pH by sonolysis of CHCl 3 –H 2 O solvents mixture.

The present work deals with the hydrodynamic behavior of several room-temperature ionic liquids presenting the same bis(trifluoromethanesulfonyles)imide anion, associated with four different cations: 1-butyl-3-methylimidazolium, 1-octyl-3-methylimidazolium, N-trimethyl-N-propylammonium and 1-butyl-1-methylpyrrolidinium cations. Steady state voltammetry was used as an electrochemical technique to characterize mass transfer in both silent and sonicated conditions, using a rotating disk electrode. Results obtained in RTILs media are compared to those acquired in synthetic solutions of controlled viscosity, in order to develop a better understanding of the phenomena involved in such media.

Extraction of tetrachloroaurate or tetrabromoaurate anions has been carried out at acidic pHs (1 and 4) with several ionic liquids bearing halide or bis(trifluoromethanesulfonyl)imide NTf2− anions and cations 1-octyl-3-methylimidazolium, 1-octylpyridinium or 1-methyl-1-octylpyrrolidinium. The removal of gold anionic moieties from water was first studied by mixing aqueous solutions containing gold complexes and water soluble halide (chloride or bromide) ionic liquids. This lead to the formation of either a solid precipitate or a liquid phase corresponding to a hydrophobic ionic liquid based on a tetrahalogenoaurate anion. Values below 10−6 for the solubility products of gold-bearing ionic liquids were obtained. Liquid–liquid extraction of anionic gold complexes with hydrophobic ionic liquids was also carried out. Gold was successfully extracted from water whatever the pH and the ionic liquid used. Distribution coefficients ranged from 3 × 102 to 3 × 104. Investigation on the extraction mechanism revealed an anion exchange between one anionic gold complex and one NTf2− anion.