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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...

Rice husk is one of the most abundant waste lignocellulosic materials. Prob sonication assisted ionic liquid treatment being time effective and environmental benign was utilized for conversion of such waste residue into valuable products. Ionic liquids have been emerged as effective and benign solvents in this regard. Here, two ionic liquids mono- and di-cationic were synthesized and compared for the processing of rice husk biomass. The synthesized ionic liquids’ structures were confirmed by Nuclear Magnetic Resonance (NMR) as well as their thermal stability was investigated using thermogravimetric analysis (TGA). The acidity values were measured using Uv–Vis spectroscopy which showed that di-cationic ionic liquid has higher acidity. For the processing of rice husk, the conventional heating and probe sonication methods were used and compared. The probe sonication assisted ionic liquid method exhibited better performance. The process was optimized with respect to type of ILs, biomass loading, particle size, time and recycling effect etc. The regenerated fibrous material was characterized through, Fourier-Transform Infrared (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) techniques. Moreover, about 39% of the lignin was successfully extract. High-Performance Liquid Chromatography (HPLC) result shows that 41.78% levulinic acid (LA) was obtained for ILs treated samples. In addition, the silica was successfully extracted from treated biomass and characterized with FTIR and Brunauer-Emmett-Teller (BET) analysis for surface area, pore size, and average diameter. It is steadily believed that the present approach would open new pathways for the efficient conversion of rice husk into sustainable products for numerous applications.

Extracting the trapped oil into the pores is still a massive challenging. In this work, multiwalled carbon nanotubes were utilized to investigate the influence of the nanofluid’s flow rate on the oil recovery in enhanced oil recovery (EOR) stage. At the optimum conditions, comparative study was conducted to figure out the impact of EM waves on the recovery efficiency. The experimental study proved that 2 mL/min is the optimum flow rate for the utilized fluid. EM waves could enhance the recovered oil in EOR stage by 24.5% ROIP. The increment was ascribed to the extraordinary role of EM waves in increasing the viscosity of the nanofluid.

Ionic liquids are promising materials for several applications. Amino acid based ionic liquids (AAILs) as a sort of a new generation of ionic liquids are recently proposed taking advantage of hydrogen bonding group and low toxicity. Three types of AAILs are examined in this work; namely 1-Octyl-3-Methylimidazolium Glycine [OMIM][Gly], 1-Octyl-3-Methylimidazolium Alanine [OMIM][Ala] and 1-Octyl-3-Methylimidazolium Proline [OMIM][Pro]. The pH and molar conductivity are measured at ambient conditions for AAILs aqueous solutions at different concentrations; specifically 1, 10, 20, and 30 wt.%. The experimental results show that all AAILs solutions are alkaline (pH>7) where [OMIM][Pro] has the highest pH compared to its counterparts. The trend is reversed for molar conductivity as [OMIM][Gly] showed the highest molar conductivity. These results are attributed to the smaller size of [Gly] compared to [Pro] and [Ala]. However, adding AAILs increases the molar conductivity of the water.

Extracting the trapped oil in the pores and channels of rock reservoirs, after secondary recovery, using traditional enhanced oil recovery (EOR) techniques is still a challenging task. Nano-materials offer novel pathways to address these unsolved challenges as EOR agents due to their unique characteristics. This study aimed to investigate the novel use of zinc oxide nanocrystals (ZnO-NCs) in EOR and, investigate the influence of the combination of ZnO-NCs with EM energy irradiation on the recovery efficiency. For this purpose, different nanofluid concentrations and flow rates, as well as brine salinity was injected into the porous medium, in the absence of EM energy, to obtain the optimum experimental conditions with the highest recovery efficiency. The injected nanofluid in the porous medium, under the optimum conditions, was subjected to EM energy. The Zinc oxide nanofluid (ZnO-NF) showed a significant rise in recovery efficiency in the absence of EM energy by 50% ROIP due to the self-assembling of the ZnO-NCs which resulted in an increment in the local viscosity of the nanofluid at the water–oil interface. This study proved the capability of EM energy to enhance the viscosity of the injected ZnO-NF in the porous medium, which consequently increased the recovery efficiency by 23.3% ROIP through the electrorheological effect of the activated dielectric ZnO-NCs.

The past few decades had seen a rapid hike in the world's population, which has caused an excessive use of fossils and, consequently, the diminution of fossil resources and the advent of global pollution problems. In this regard, the renewable and eco-friendly properties of biodiesel fuel provide an alternative to petroleum fuel. Many countries are looking into the use of biodiesel, particularly countries that are more susceptible to environmental problems. Biodiesel could be synthesized from different origins, including organic oils from animal fats and vegetables. At the same time, the production of biodiesel from vegetable edible oils can create food security problems; hence, the selection of cheap sources, like animal fats, is a valuable feedstock, but its availability is limited. Thus, more preferable sources other than low-cost feedstocks with high free fatty acids content include unrefined crude oils, discarded cooking oil and inedible oils. This paper is aimed to highlight biodiesel and its availability from various feedstock for its preparation. It also discussed how the ionic liquids (ILs) can be the catalysts to produce biodiesel; these liquids are sourced by different feedstocks by transesterification method. Due to several limitations and problems associated with traditional homogeneous and heterogeneous catalysts in recent years, ILs are increasingly used as the catalysts or solvents for free fatty acids esterification, as well as the transesterification of vegetable oils. This paper is focused on the transesterification of fatty acid with ILs, cost and recycling of ILs, the effects of adding enzyme, Lewis acids and amines on ILs catalysed reaction, the use of Bronsted acidic, basic and dicationic basic ILs as the sole solvent which supported acid/base-catalysed IL for biodiesel synthesis. In addition, the proper research focuses and new developments in this regard would make the ILs as an ideal catalyst for biodiesel preparation from various feedstocks.

In this study, imidazolium based ionic liquids with different functional group were chemically tethered to silica support and resulted in silica supported solid ionic liquids phases (SILPs). The SILPS were characterized using CHNS elemental analysis, Fourier Transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermo gravimetric analysis (TGA). The adsorption of commercial naphthenic acid from dodecane/kerosene was performed using SILPs. It was observed that their adsorption efficiency varied depending on the functional group on the imidazolium cation. This study was also modeled using COSMO-RS. The SILPs are efficient adsorbent in the extraction of naphthenic acid from highly acidic model oil. The recovery of adsorbed naphthenic acids from the SILPs was also investigated.

Over the past decades, Ionic liquids (ILs) have gained considerable attention from the scientific community in reason of their versatility and performance in many fields. However, they nowadays remain mainly for laboratory scale use. The main barrier hampering their use in a larger scale is their questionable ecological toxicity. This study investigated the effect of hydrophobic and hydrophilic cyclic cation-based ILs against four pathogenic bacteria that infect humans. For that, cations, either of aromatic character (imidazolium or pyridinium) or of non-aromatic nature, (pyrrolidinium or piperidinium), were selected with different alkyl chain lengths and combined with both hydrophilic and hydrophobic anionic moieties. The results clearly demonstrated that introducing of hydrophobic anion namely bis((trifluoromethyl)sulfonyl)amide, [NTF2] and the elongation of the cations substitutions dramatically affect ILs toxicity behaviour. The established toxicity data [50% effective concentration (EC50)] along with similar endpoint collected from previous work against Aeromonas hydrophila were combined to developed quantitative structure-activity relationship (QSAR) model for toxicity prediction. The model was developed and validated in the light of Organization for Economic Co-operation and Development (OECD) guidelines strategy, producing good correlation coefficient R2 of 0.904 and small mean square error (MSE) of 0.095. The reliability of the QSAR model was further determined using k-fold cross validation.

In this present research, five nitrile functionalised imidazolium based protic ionic liquids (PILs) by varying alkyl chain length of anions were synthesized. The synthesized ILs were characterized with nuclear magnetic resonance spectroscopy (NMR) and elemental analyser (CHNS). Various thermophysical properties such as refractive index, density, viscosity and thermal stability were measured over wide temperature range. From the density experimental data, different volumetric properties were estimated using well established empirical equations. Moreover, the effect of temperature and increase of alkyl substitutions attached to anion has been evaluated for the studied properties. The toxicity of the synthesized ILs has been assessed against three human pathogenic bacteria i.e., Aeromonas hydrophila A97 (AH), Escherichia coli E149 (EC), and Staphylococcus aureus S244 (SA) in light to identify the influence of increasing alkyl substitution of the anion moiety on the overall toxicity of PILs.

A simple controlled synthesis method for supported hollow NiO crystals from an octahedral morphology to their different truncated shapes was successfully obtained by utilizing a facile wet-impregnation method through controlling the calcination temperature.

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.

Ionic liquids (ILs) are class of solvent whose properties can be modified and tuned to meet industrial requirements. However, a high number of potentially available cations and anions leads to an even increasing members of newly-synthesized ionic liquids, adding to the complexity of understanding on their impact on aquatic organisms. Quantitative structure activity∖property relationship (QSAR∖QSPR) technique has been proven to be a useful method for toxicity prediction. In this work,σ-profile descriptors were used to build linear and non-linear QSAR models to predict the ecotoxicities of a wide variety of ILs towards bioluminescent bacterium Vibrio fischeri. Linear model was constructed using five descriptors resulting in high accuracy prediction of 0.906. The model performance and stability were ascertained using k-fold cross validation method. The selected descriptors set from the linear model was then used in multilayer perceptron (MLP) technique to develop the non-linear model, the accuracy of the model was further enhanced achieving high correlation coefficient with the lowest value being 0.961 with the highest mean square error of 0.157.

Metal-metal oxide composite materials have been garnering wide attention due to their extraordinary properties and applications in several areas. Ni-NiO is an important composite; its synthesis and properties have been of increased interest with regards to prominent applications in many fields. This article provides for the first time a comprehensive review of the cutting-edge research activities that focus on rational synthesis, characterization techniques, novel properties and applications of the Ni-NiO composite. While the formation mechanism of this composite is still vague, much attention has been given to the reported formation mechanisms using different precursors in one-pot synthesis, and thus, a formation mechanism and green synthesis route have been proposed. All the applications of the Ni-NiO composite in different fields including magnetic materials, ion-lithium battery, supercapacitors and catalytic activities are also emphasized. It was proved from the available literature that metallic Ni was obtained into the skelton of NiO by the reduction process during the calcination through the production of adventitious H2 via the gasification-like process.

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.

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.

A series of new synthesized ionic liquids based on 1-octyl-3-methylimidazolium with glycinate, alaninate, serinate, prolinate, and asparaginate anions were prepared. Their thermophysical properties (density, viscosity, surface tension, and heat capacity) were measured at various temperatures and atmospheric pressures. Physicochemical properties such as thermal expansion coefficient values, molecular volume, standard molar entropy, and lattice energy standard were also determined using empirical methods. The effects of anions on the studied properties were further analyzed.

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%.