Imidazolium Chloride Ionic Liquid Research Articles

Effect of support type on the characteristics of polybutene polymers from C4 monomers employing supported ionic liquid/AlCl3 initiating systems

In order to assess the effect of support type on the characteristics of polybutene polymers, cyclohexyl imidazolium chloride ionic liquid was grafted onto the surface of various supports including boehmite, halloysite, palygorskite, and kaolinite. The furnished supported ionic liquids were employed alongside AlCl3/ethanol as initiating systems to polymerize C4 monomers, resulting in polybutene polymers. Overall, XRD, FTIR, TGA, SEM, EDS, and Elemental Mapping Analyses convinced the successful homogenous grafting of ionic liquid onto the surface of subjected supports. To obtain precious and essential information about molecular weight, dispersity, and microstructure of polymers, GPC, 1H NMR, and 13C NMR analyses were conducted. Among the four initiating systems, kaolinite supported ionic liquid demonstrated the most satisfying results, Yield = 88.2 %, Mn= 18104 g mol−1, Ð = 1.83, exo= 6.1 % and isobutylene content of 92.5 %. Hence, this supported ionic liquid was fully characterized via SEM, EDX, Elemental Mapping, XRD, FT IR and TGA analyses. To get deeper insight about the type and quantity of molecular interactions in the kaolinite supported ionic liquid, molecular modeling calculation was also considered. Beside efficiently balancing polymerization condition, implementing the AlCl3/ionic liquid initiating system promotes a more environmentally friendly polymerization approach by halving the amount of hazardous AlCl3 compared to the blank system including neat AlCl3 as the single co-initiator.

Conductometric and Thermodynamic Studies of Selected Imidazolium Chloride Ionic Liquids in N,N-Dimethylformamide at Temperatures from 278.15 to 313.15 K.

This scientific article presents research on the electrical conductivity of imidazole-derived ionic liquids (1-methylimidazolium chloride, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride and 1-methyl-3-octylimidazolium chloride) in the temperature range of 278.15-313.15 K in N,N-Dimethylformamide. The measurement methods employed relied mainly on conductometric measurements, enabling precise monitoring of the conductivity changes as a function of temperature. Experiments were conducted at various temperature values, which provided a comprehensive picture of the conducting properties of the investigated ionic liquids. The focus of the study was the analysis of the conductometric results, which were used to determine the conductivity function as a function of temperature. Based on the obtained data, a detailed analysis of association constants (KA) and thermodynamic parameters such as enthalpy (∆H0), entropy (∆S0), Gibbs free energy (∆G0), Eyring activation enthalpy for charge transport (ΔHλ‡) and diffusion processes (D0) was carried out. The conductometric method proved to be an extremely effective tool for accurately determining these parameters, significantly contributing to the understanding of the properties of imidazole-derived ionic liquids in the investigated temperature range. As a result, the obtained results not only provide new insights into the electrical conductivity of the studied ionic liquids but also broaden our knowledge of their thermodynamic behavior under different temperature conditions. These studies may have significant implications for the field of ionic liquid chemistry and may be applied in the design of modern materials with desired conducting properties.

Elucidating the stabilization mechanism of a K+-depleted c-MYC DNA G-quadruplex in hydrophobic imidazolium-based ionic liquids using spectroscopy coupled with molecular dynamics simulations

Stabilizing native nucleic acid structures is critical for developing nucleic acid-based therapeutics, which have enormous potential in biomedicine for disease prevention, disease treatment and diagnostics. Imidazolium chloride ionic liquids (ImCl ILs) can increase the thermal stability of G-Quadruplex DNA structures. Generally, G-Quadruplex DNA requires K+ (or sometimes Na+) to stabilize their structures via coordination of the guanine bases. In this work we investigated the ability of ImCl ILs to stabilize G-Quadruplex DNA without K+ present. Temperature-dependent CD spectroscopy showed that the ImCl ILs that can form micelles in aqueous solution ([OMIM]Cl and [DMIM]Cl) increase the thermal stability of G-Quadruplex DNA without K+, while the ImCl ILs that do not form micelles ([EMIM]Cl, [BMIM]Cl, and [HMIM]Cl) do not stabilize the structure. Notably, [OMIM]Cl and [DMIM]Cl only stabilize G-Quadruplex DNA at concentrations above their CMC values; at concentrations equal to their CMC values these ILs actually destabilize the structure. MD simulations were performed to elucidate the mechanism of thermal stabilization. Simulations are consistent with experimental results as [DMIM]Cl micelles keep the G-Quadruplex structure stable without K+ present. These results show how ILs can encapsulate and stabilize DNA, which can help guide the development of new strategies for stabilizing DNA and RNA structures at room temperature.

Experimental and Simulation Studies of Imidazolium Chloride Ionic Liquids with Different Alkyl Chain Lengths for Viscosity Reductions in Heavy Crude Oil: The Effect on Asphaltene Dispersion.

Heavy crude oil poses challenges in terms of extraction and transportation due to its high viscosity. In the pursuit of effective methods to reduce viscosity in heavy crude oil, this study investigates the potential of imidazolium chloride ionic liquids with varying alkyl chain lengths as viscosity reducers. The experimental results demonstrate that the addition of 1-dodecyl-3-methylimidazole chloride ([C12-MIM]Cl) leads to a maximum viscosity reduction of 49.87%. Solubility parameters were calculated based on characterization of the average molecular structure of the asphaltenes. The viscosity reduction effect is enhanced when the solubility parameter of the ionic liquid closely matches that of the asphaltene. The initial asphaltene deposition point of heavy crude oil is increased from 63% to 68% with the addition of 150 mg/L [C12-MIM]Cl. Furthermore, the average particle size of asphaltene deposits decreases from 79.35 μm to 48.54 μm. The viscosity of heavy crude oil is influenced by the aggregation of asphaltenes. The ability of ionic liquids, especially those with longer alkyl chains, to disperse asphaltene molecules and reduce viscosity has been confirmed through molecular dynamics and quantum mechanical simulations.

Influencing ionic conductivity and mechanical properties of ionic liquid polymer electrolytes by designing the chemical monomer structure

ABSTRACTPolymeric single chloride-ion conductor networks based on acrylic imidazolium chloride ionic liquid monomers AACXImCYCl as reported previously are prepared. The chemical structure of the polymers is varied with respect to the acrylic substituents (alkyl spacer and alkyl substituent in the imidazolium ring). The networks are examined in detail with respect to the influence of the chemical structure on the resulting properties including thermal behavior, rheological behavior, swelling behavior, and ionic conductivity. The ionic conductivities increase (by two orders of magnitude from 10−6 to 10−4 S·cm−1 with increasing temperature), while the complex viscosities of the polymer networks decrease simultaneously. After swelling in water for 1 week the ionic conductivity reaches values of 10−2 S·cm−1. A clear influence of the spacer and the crosslinker content on the glass transition temperature was shown for the first time in these investigations. With increasing crosslinker content, the Tg values and the viscosities of the networks increase. With increasing spacer length, the Tg values decrease, but the viscosities increase with increasing temperature. The results reveal that the materials represent promising electrolytes for batteries, as proven by successful charging/discharging of a p(TEMPO-MA)/zinc battery over 350 cycles.

Reaction and separation system for CO2 hydrogenation to formic acid catalyzed by iridium immobilized on solid phosphines under base-free condition

Hydrogenation of carbon dioxide (CO2) to produce formic acid (HCOOH) in base-free condition can avoid waste producing and simplify product separation process. However, it remains a big challenge because of the unfavorable energy in both thermodynamics and dynamics. Herein, we report the selective and efficient hydrogenation of CO2 to HCOOH under neutral conditions with imidazolium chloride ionic liquid as the solvent, catalyzed by a heterogeneous Ir/PPh3 compound. The heterogeneous catalyst is more effective than the homogeneous one because it is inert in catalyzing the decomposition of product. A turnover number (TON) of 12700 can be achieved, and HCOOH with a purity of 99.5% can be isolated by distillation because of the non-volatility of the solvent. Both the catalyst and imidazolium chloride can be recycled at least 5 times with stable reactivity.

A fiber-packed needle-type extraction device with ionic liquid-based molecularly imprinted polymer as coating for extraction of chlorobenzenes in water samples

A needle-type extraction device (NTED) packed with ionic liquid-based molecularly imprinted polymers (MIP) coated copper fiber was produced for extraction of chlorobenzenes (CBs) in the aqueous environment followed by detection with GC-FID. Precipitation polymerization was performed to synthesize CBs imprinted polymers (CBs-MIP) with CBs as a mixed template, and 1-vinyl-3-aminoformylmethyl imidazolium chloride ionic liquid ([VAFMIM]Cl) as a functional monomer. Then CBs-MIP was coated on the braided copper fiber surface by sol–gel technology, which was served as a coated fiber to extract five trace CBs in drinking water, river water and industrial wastewater. The effects of several experimental conditions on extraction, including extraction time and temperature, pump flow rate, stirring speed, desorption time and temperature were studied by the single factor and experimental design method. A Plackett-Burman design (PBD) was used to screen the significant factors and a Box-Behnken design (BBD) was applied to optimize the significant variables to obtain the optimum extraction conditions. The limits of detection (0.0073–0.0130 μg L−1) and enrichment factors (2158–4087) for studied CBs were obtained after optimization. Moreover, the recoveries of CBs spiked in real water samples were 80.01–97.10% with RSD less than 7.70%. The experimental results confirmed that the NTED packed with CBs-MIP coated fiber is a promising device for extracting trace CBs from the water matrix.

Solid‐phase extraction based on PDMS/ionic liquid sponge followed by gas chromatography–mass spectrometry for rapid and sensitive determination of volatile components in lavender

Due to the complexity and the low concentrations of volatile components in aromatic plants, sample pretreatment is an important step in the whole analytical procedure. This study aimed to propose a novel, sensitive and fast approach to determine the volatile components in lavender. The 1-butyl-3-(propyltrimethoxysilane)imidazolium chloride ([BPtmsim]Cl) ionic liquid was introduced onto the surface of polydimethylsiloxane (PDMS) to prepare a novel PDMS/[BPtmsim]Cl sponge with large surface area, good sorption performance, and reusability. A solid-phase extraction method was developed based on PDMS/[BPtmsim]Cl sponge combined with gas chromatography-mass spectrometry (GC-MS). The effects of the various experimental parameters on the extraction efficiency were investigated. The optimal conditions were [BPtmsim]Cl amount of 0.3g, 1:4 as the mass ratio of PDMS/[BPtmsim]Cl to lavender sample, microwave power of 700 W, microwave time of 10min, and n-hexane as the desorption solvent. The method validation results showed good linearity (10-800 μg/ml), high correlation coefficient (R2 ≥ 0.9991), low limits of detection (1.73-2.50 ng/μl), and limits of quantification (4.10-5.11 ng/μl). The interday and intraday precision with relative standard deviation (RSD) values were below 1.93% and 4.71%, respectively. Under the optimal extraction conditions, 16 lavender samples from three different species were analysed and a total of 57 volatile compounds were identified. The correlation between different species of lavender and volatile components was explored using principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). The results showed that PDMS/[BPtmsim]Cl extraction is a rapid, highly efficient, and sensitive technique for the determination of volatile components in complex plant samples.

The physicochemical properties of selected imidazolium chloride ionic liquids in tetraethylene glycol: Experimental and computational approach

In this work, the influence of the side chain length of five ionic liquids (ILs) containing N3-substituted 1-methylimidazolium chloride ionic liquids, [Cnmim][Cl] (n = 0, 1, 2, 4, 6) on the interactions with tetraethylene glycol (TEG) was studied. Measuring the density and electrical conductivity of the IL + TEG mixtures in the temperature range (278.15–313.15) K, the values of physicochemical properties, such as apparent molar volume, apparent molar volume at infinite dilution, Masson’s interaction coefficient, limiting apparent molar expansibilities, Heppler’s coefficient, ion association constants, thermodynamic parameters of ion-pair formation, as well as diffusion coefficient were calculated. The results obtained from these experiments were supported by molecular dynamics (MD) simulations. In comparation with systems containing ethylene–glycol (IL + EG), the calculated free volumes in TEG are about three times higher than in EG. Therefore, assuming that the packing effect is responsible for the lower apparent molar volume at infinite dilution, values in the TEG seem reasonable. The values of ion association constants in TEG are lower than in EG. The ion association process is spontaneous for all investigated ILs in TEG solutions and entropy-driven.

Theoretical Analysis of Physical and Chemical CO2 Absorption by Tri- and Tetraepoxidized Imidazolium Ionic Liquids.

The efficient capture of CO2 from flue gas or directly from the atmosphere is a key subject to mitigate global warming, with several chemical and physical absorption methods previously reported. Through polarizable molecular dynamics (MD) simulations and high-level quantum chemical (QC) calculations, the physical and chemical absorption of CO2 by ionic liquids based on imidazolium cations bearing oxirane groups was investigated. The ability of the imidazolium group to absorb CO2 was found to be prevalent in both the tri- and tetraepoxidized imidazolium ionic liquids (ILs) with coordination numbers over 2 for CO2 within the first solvation shell in both systems. Thermodynamic analysis of the addition of CO2 to convert epoxy groups to cyclic carbonates also indicated that the overall reaction is exergonic for all systems tested, allowing for chemical absorption of CO2 to also be favored. The rate-determining step of the chemical absorption involved the initial opening of the epoxy ring through addition of the chloride anion and was seen to vary greatly between the epoxy groups tested. Among the groups tested, the less sterically hindered monoepoxy side of the triepoxidized imidazolium was shown to be uniquely capable of undergoing intramolecular hydrogen bonding and thus lowering the barrier required for the intermediate structure to form during the reaction. Overall, this theoretical investigation highlights the potential for epoxidized imidazolium chloride ionic liquids for simultaneous chemical and physical absorption of CO2.

Effects of the Ionic Liquid [BMIM]Cl on the Baltic Microphytobenthic Communities

Ionic liquids (IL) are regarded as the solution to the modern world’s need to create and use compounds that exhibit a range of desirable properties while having a low environmental impact. However, recent reports are shattering the image of ionic liquids as environmentally friendly substances, especially in relation to the aquatic environment, revealing their potentially toxic effects. To assess the potential environmental impact of ILs, we conducted an experiment involving 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), a substance considered to be the least hazardous among the imidazolium chloride ILs, on Baltic microphytobenthic communities. Microphytobenthos collected from the environment was tested under controlled laboratory conditions, and both the cell counts and the chloroplast condition were used as endpoints. It was shown that [BMIM]Cl at concentrations of 10−3 and 10−2, considered safe based on a cumulative impact assessment, has a negative effect on the condition of the microalgal cells and causes a reduction in population size. Although, under the influence of [BMIM]Cl, only a small proportion of the species was eliminated from the communities, only two species among those important to the communities showed resistance to this compound and eventually began to dominate the communities.

Mesoporous ionic liquid functionalized nanozeolite: Synthesis and high efficient material to improving pseudocapacitance performance of conductive polymer

Supercapacitors are emerging as a competitive candidate for electrochemical energy storage owing to their greater power outputs and longer cycle life than rechargeable batteries. In this work, a chloropropyl grafted zeolite-NaY modified with imidazolium chloride ionic liquid (Im-Cl IL@ZY) has been successfully synthesized by a chemical method. Notably, the imidazolium chloride ionic liquid enhances the electrical contact between zeolite network and conductive polymer film (poly ortho aminophenol) because of its high conductivity and good compatibility with different substances. The synergistic effect of the most efficient composite endows the hybrid electrode with a high specific capacitance of 665 F/g F g−1 at 1 A g−1 and reliable cycling stability of 88 % capacitance retention after 8000 cycles. Moreover, a symmetric supercapacitor based on the composite electrodes achieves a high energy density of 36.7 W h kg−1 at a power density of 485 W kg−1. Results highlight that POAP/Im-Cl IL@ZY composites are promising materials for energy storage devices with long cycling stability.

Imidazolium Chloride Ionic Liquid Mixtures as Separating Agents: Fuel Processing and Azeotrope Breaking.

Relevant chemical separations for the petrochemical and chemical industries include the removal of aromatic hydrocarbons from aliphatics, the desulfurization and denitrification of fuels, and the separation of azeotropic mixtures containing alkanols. In an attempt to contribute to the development of novel technologies, the potentialities of imidazolium chloride ionic liquid (IL) mixtures as separation agents were investigated. Selectivities, capacities, and solvent performance indices were calculated through the activity coefficients at infinite dilution of organic solutes and water in the imidazolium chloride IL: [C8mim]Cl, [C12mim]Cl, and the equimolar mixture of [C4mim]Cl and [C12mim]Cl. Results show that the imidazolium chloride IL might be appropriately tailored for specific purposes, in which an increase in the proportion of cations containing larger alkyl chains tends to increase the overall affinity with organic solutes. The IL designer solvent concept was explored by comparing the IL equimolar mixture results with the intermediary [C8mim]Cl. The COSMO-RS thermodynamic model was also applied, showing it to be a promising tool for a fast qualitative screening of potential separation agents for specific separation processes.

Phosphotungestic acid and manganese containing periodic mesoporous organosilica with imidazolium ionic liquid framework: A robust and durable nanocomposite for desulfurization of aromatic sulfur in diesel fraction

As sulfur compounds produced by the combustion of fossil fuels are one of the main elements in air pollution, some strict legislation has been issued that specifies the sulfur ratios of different fuels. Therefore, periodic mesoporous organosilicas (PMO) composed of 1,3- bis(trimethoxysilylpropyl)imidazolium chloride ionic liquid, 1,2- bis(trimethoxysilyl)ethane, and phosphotungstic acid or permanganate as counter ions of imidazolium moieties in the framework of PMO-IL were fabricated to obtain highly reactive -MnO4 or -HPW12O40 based heterogeneous catalysts. The synthesized materials were characterized by FT-IR, N2 adsorption–desorption, low and wide-XRD, XPS, TGA, and HRTEM. The surface area was of 615, 425 and 347 m2 g–1 for PMO-IL, HPW12O40–PMO-IL and MnO4- PMO-IL, respectively. The desulfurization was studied on three types of aromatic sulfur models. The results revealed that MnO4-PMO-IL and HPW12O40– PMO-IL outperform other catalysts in the oxidative desulfurization process of three kinds of aromatic sulfur compounds; comprising benzothiophene, dibenzothiophene, and 4, 6-dimethyldibenzothiophene even at smaller O/S ratio. The MnO4–PMO-IL catalyst showed the maximum efficiency in reducing sulfur at 50 °C, as it achieved sulfur reduction rates of 93.2, 92.7, and 98.8% after 90 min, while the HPW12O40– PMO-IL catalyst showed a reduction of sulfur by 85.1, 94.3 and 98% after 120 min for BT, DBT, and 4,6-DMDBT compounds, respectively. The two catalysts can be suggested as effective catalysts for oxidative desulfurization of fuel. Furthermore, our research showed that the catalyst might be retrieved and reused at least nine times without a noticeable loss in performance.

Optimization of Fenton Oxidation Process for Degradation of 1-Butyl-3 Methyl Imidazolium Chloride (BMIMCL) Using Response Surface Methodology

The degradation of 1-butyl 3-methyl imidazolium chloride (BMIMCl) ionic liquid (IL) by Fenton oxidation has been studied. The optimization of operating parameters for maximum degradation of BMIMCl has been carried out using the Central Composite Design (CCD) of Response Surface Methodology (RSM). The three independent input parameters selected were the dosage of Hydrogen Peroxide (H2O2), the dosage of iron (Fe2+), and the pH of the output or response selected was Total Organic Carbon (TOC) removal efficiency. Experiments were carried out according to the experimental design provided by CCD. For TOC Degradation, the model’s R2 and R2adj correlation coefficients between experimental and model-predicted values were 0.9769 and 0.9561, respectively. This indicates a satisfactory correlation of experimental results with model-predicted values. The optimum values of operating parameters for maximum degradation were found to be H2O2=307 mM (X1), Fe2+=1.1 mM (X2), and (pH)=3.3 (X3), for a reaction time of 120 min. For these operating parameters, the experimental result for TOC removal efficiency was found to be 72.89% as compared to the model-predicted value of 73.67%. These results indicate that the values were closely correlated with each other and thus the model was validated satisfactorily. Overall, the results indicate that the BMIMCl ionic liquid can be effectively degraded by the Fenton oxidation process.

Interactions between a dsDNA Oligonucleotide and Imidazolium Chloride Ionic Liquids: Effect of Alkyl Chain Length, Part I.

Ionic liquids (ILs) have become nearly ubiquitous solvents and their interactions with biomolecules has been a focus of study. Here, we used the fluorescence emission of DAPI, a groove binding fluorophore, coupled with molecular dynamics (MD) simulations to report on interactions between imidazolium chloride ([Imn,1]+) ionic liquids and a synthetic DNA oligonucleotide composed entirely of T/A bases (7(TA)) to elucidate the effects ILs on a model DNA duplex. Spectral shifts on the order of 500–1000 cm−1, spectral broadening (~1000 cm−1), and excitation and emission intensity ratio changes combine to give evidence of an increased DAPI environment heterogeneity on added IL. Fluorescence lifetimes for DAPI/IL solutions yielded two time constants 0.15 ns (~80% to 60% contribution) and 2.36–2.71 ns for IL up to 250 mM. With DNA, three time constants were required that varied with added IL (0.33–0.15 ns (1–58% contribution), ~1.7–1.0 ns (~5% contribution), and 3.8–3.6 ns (94–39% contribution)). MD radial distribution functions revealed that π-π stacking interactions between the imidazolium ring were dominant at lower IL concentration and that electrostatic and hydrophobic interactions become more prominent as IL concentration increased. Alkyl chain alignment with DNA and IL-IL interactions also varied with IL. Collectively, our data showed that, at low IL concentration, IL was primarily bound to the DNA minor groove and with increased IL concentration the phosphate regions and major groove binding sites were also important contributors to the complete set of IL-DNA duplex interactions.

Volumetric properties, conductivity and computation analysis of selected imidazolium chloride ionic liquids in ethylene glycol

In this paper, the influence of the side chain length of five ionic liquids (ILs): 1-methylimidazolium chloride ([C0mim][Cl]), 1,3-dimethylimidazolium chloride (([C1mim][Cl]), 1-ethyl-3-methylimidazolium chloride (([C2mim][Cl]), 1-butyl-3-methylimidazolium chloride (([C4mim][Cl]) and 1-hexyl-3-methylimidazolium chloride (([C6mim][Cl]) on the interactions with ethylene glycol (EG) was studied. Based on the measurement of density and electrical conductivity of the ionic liquid + EG mixture in the temperature range (278.15–313.15) K, the values of apparent molar volume, standard partial molar volumes, apparent molar volume at infinite dilution, Masson’s interaction coefficient, thermal expansion coefficient, limiting apparent molar expansibilities, Heppler’s coefficient, ion association constants, thermodynamic parameters of ion-pair formation as well as diffusion coefficient was calculated. Experimental results were supported by molecular dynamic simulations. With the increase of the side chain length, from C0mim+ to C6mim+ cation, ion–dipole interactions on the solvation process decrease, and the influence of solvophobic solvation increases. Ionic liquids [C0mim][Cl] and [C1mim][Cl] show structure-breaker properties, [C4mim][Cl] and [C6mim][Cl] structure-making properties in EG solutions, while [C2mim][Cl] is borderline. The values of ion association constants in EG are higher than in water. The ion association process is spontaneous for all ionic liquids and entropy-driven.

Physiological responses of Pichia stipitis to imidazolium chloride ionic liquids with different carbon chain length

Ionic liquids (ILs) are used as detoxication agents for fermentation of lignin into ethanol because of their good applicability. However, the residual ILs may be toxic to the yeast. In order to improve the use of ILs for fermentation and protected environment, the toxicity of ILs with different carbon chain length to Pichia stipitis was studied in this paper. Four kinds of common imidazolium chloride ILs ([C4mim]Cl, [C6mim]Cl, [C8mim]Cl and [C10mim]Cl) were selected. ILs can inhibit the proliferation of Pichia stipitis and increase their mortality. Oxidative stress reaction occurred in the cells, and the activities of antioxidant enzymes are affected. Comparing with the integrated biomarker response (IBR) index, it was found that the toxicity increases with increasing chain length. ILs may enter cells by damaging cell membranes and reduce ethanol production by damaging organelles such as mitochondria. ILs caused wrinkles and dents on the surface of cells up to cell deformation and even rupture. The toxicity sequence was as follows: [C10mim]Cl> [C8mim]Cl>[C6mim]Cl>[C4mim]Cl. Due to this toxicity to Pichia stipitis, these compounds should be used carefully in the fermentation process and also to avoid toxic effects on other organisms in the environment.

A new yolk-shell hollow mesoporous nanocomposite, Fe3O4@SiO2@MCM41-IL/WO42-, as a catalyst in the synthesis of novel pyrazole coumarin compounds

Hollow mesoporous silica yolk-shell nanocomposite with a magnetic core has been synthesized and functionalized with 1-methyl-(3-trimethoxysilylpropyl) imidazoliumchloride ionic-liquid. Moreover, WO42- nanoparticles were incorporated into the yolk-shell nanoparticles to prepare pyrazole coumarin in short reaction times and high yield in EtOH/H2O at 70 °C. The mosoporous silica yolk-shell with high surface area, nontoxic, and the outer and inner void layer shows excellent resistance after use in seven cycles.

Graphene oxide (GO)-coated microbubbles in imidazolium-based ionic liquid

This study presents the feasibility of coating microbubbles with graphene oxide (GO), a transpiring material that has since attracted intensive research in both fundamental science and technology developments. In this study, an imidazolium chloride ionic liquid (IL), namely 1-dodecyl-3-methylimidazolium chloride ([C12mim]Cl) at various concentrations from 100 ppm to 8000 ppm was used as the binder surfactant to bridge microbubbles and GO. The mechanism of microbubble-GO attachment studied in this research included microbubble-GO electrostatic interactions, microbubble-GO hydrophobic attraction, microbubble-GO contact angle and Gibb's free energy of a microbubble-GO system. Results showed that the optimum microbubble-GO attachment (highest contact angle and most negative Gibb's free energy) occurred at 350 ppm [C12mim]Cl in which GO achieved isoelectric point (IEP – zeta potential (ZP) of GO is at 0 mV). Since GO gained maximum hydrophobicity at IEP, it was inferred that microbubble-GO attachment was dominated by hydrophobic attraction with insignificant electrostatic interactions. Qualitative analysis further confirmed the successful attachment and production of the GO-coated microbubble in 350 ppm[C12mim]Cl. Besides that, a single microbubble in 100 ppm[C12mim]Cl at which maximum attractive electrostatic forces are anticipated between microbubbles and GO was also analysed qualitatively. Here, GO attachment onto the microbubble was not significantly observable, thus further proving the dominance of hydrophobic attraction. On a different note, the amount of GO attached onto a microbubble in 350 ppm[C12mim]Cl was also successfully quantified using UV–Vis method at which GO possessed an absorption peak centered at 233 nm. The outcomes of this study demonstrated the significance of hydrophobic attraction for microbubble-particle attachments particularly for microbubble-GO attachment and successful synthesis of GO-coated microbubbles for various applications.