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Microwave is a good candidate towards lipid extraction from microalgae in a bid to reduce the overall energetic consumption and extraction time. 1-octyl-3-methylimidazolium-based ILs belonging to 1st generation and 2nd generations, have been used. At 2.5% of [Omim][OAc] in the medium, 19.2% of lipid were obtained, while the conventional IL-less system only yielded 10.9%. More interestingly, the extraction efficiency increases with increasing amount of IL. A broader range of fatty acid profiles was also found to be extracted in the presence of ILs. The lipid extraction ability of the ILs was further confirmed and even dramatically enhanced under high pressure microwave irradiation. At 1.5% IL, the lipid yield reached 37% with FAME profile mirroring the results obtained by hydrophobic IL based extraction. The energy balance calculation have shown a reduction in the energy loss with the different type of IL used resulting in a 12% net energy gain with the [Omim][NTf2] IL based extraction. A key finding in this study suggests that both the polarity of the ILs and the electronegativity of the anions play an important role in the type of lipids extracted.

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.

In order to override the slow adsorption kinetics of micropollutants on an activated carbon fabric (ACF) in water medium, different mixing modes, i.e. orbital stirring (250 rpm), low frequency ultrasonic irradiation with either a 20 kHz probe (volumic power: 80 W/L) or a 38 kHz bath (10 W/L), were compared to promote the adsorption of ibuprofen (4 ppm initial concentration). The used ACF is formed of wowen braids made of three yarns (∼300 µm diameter), each of them being composed of microporous fiber bundles (12.6 µm diameter) and its texture was accurately characterized. The adsorption kinetics were studied in buffered phosphate solution (pH 7.5) on a disk, braids or fiber from the fabric and were simulated by a volume diffusion model. The fitted values of the external mass transfer and the volume diffusion coefficients have demonstrated the limitation of the adsorption kinetics under stirring on the fabric disks and braids by the diffusion step within the yarn in the inter-fiber macroporosity. The 20 kHz sonication coupled to the adsorption on ACF led to the degradation of ibuprofen by OH° radicals issued from water sonolysis but without damaging further the fabric. The low power irradiation at 38 kHz allowed a sharp acceleration of the adsorption kinetics with respect to the one obtained through orbital stirring. This is explained by a fast mobility of the ibuprofen owing to the presence of standing waves and absence of harsh cavitation as compared to 20 kHz probe system, and confirmed by a fitted diffusion coefficient higher than the one of molecular ibuprofen and of two order of magnitude than in stirring conditions.

This present article covers a comparative study of esterification reaction using either ultrasound cavitation or conventional mechanical stirring with a series of newly developed SO 3 H-functionalized dicationic ammonium- and DABCO-based acidic ionic liquids. As a baseline for performance evaluation, esterification reaction was also conducted with a series of SO 3 H-functionalized monocationic ammonium-based acidic ionic liquids and several conventional mineral acids (H 2 SO 4 , etc.). Their efficacy as catalyst towards perceptive esterification for the synthesis of biodiesel from free long-chain fatty acids with methanol were appraised. The Hammett acidity of these conventional acids and acidic ionic liquids were also assessed using UV–visible spectroscopy. Four factors were studied in the process of optimizing the reaction conditions, which are methanol to oil molar ratio (3–15), catalyst amount (0.2–1.0%), temperature (25–60 °C) and time (0–60 min). Whereas esterification under mechanical stirring leads to formation of a triphasic system (methanol, ionic liquids and esters) easing final separation of components, the same reaction under ultrasonic irradiation leads to formation of one phase layer at the end of reaction but the esters were simply isolated using centrifugation. The results showed that whatever ultrasound or mechanical stirring, the use of dicationic ionic liquids authorized better conversion yields of free fatty acid (FFA) into fatty acid methyl esters (FAME) with better yields than with either monocationic ionic liquids or mineral acids. The novel ionic liquids together with the design of a clean procedure offers advantages including short reaction time, good yield, operational simplicity, and environmentally benign characteristics.

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.

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.

Development of covalent organic polymer (COP) is a potential new class of adsorbent for gas separation due to their good hydrothermal stability, chemical tuning flexibility and low cost. COP-1 was prepared via one-step polycondensation of cyanuric chloride and piperazine under catalyst free and N2 atmosphere condition. The properties of COP-1 were characterized using several analytical methods such as Fourier Transform Infra-Red (FTIR), solid Nuclear Magnetic Resonance (s-NMR), Thermal gravimetric analysis (TGA) and N2 adsorption and desorption measurement. The C-N bond of COP-1 which has non-rigid framework was successfully linked in this study. It is found that COP-1 has low thermal degradation temperature i.e. 483 K. As compared to literature, lower surface area (75.5 m2/g) and slightly large pore size (8 nm) are noticed. The difference of physical properties of COP-1 synthesized between in this study and literature revealed the challenge of reproducibility for COP-1.

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.

Owing to their remarkable physical-chemical properties, Ionic Liquids are considered as very promising capturing/transportation fluids in biotechnological applications for gaseous pollutants such as Carbon dioxide (CO2) which can be then remediated by living microorganisms. However, Ionic Liquids are also toxic towards the majority of living species used for remediation purposes among green microalgae. In this study different ionic liquids were tested for their toxicity for different concentrations on one type of commonly used green microalgae, Botryococcus braunii. Ionic liquids bearing long alkyl chain do display higher CO2 uptake than ioni liquids analogue bearing shorter alkyl chain. This might explain why the production of biomass is dramatically enhanced with 1-octyl-1-Methyl Piperidinium bis (trifluoromethylsulfonyl) imide OMPip[NTf2] compared to 1-Butyl-1-Methyl Piperidinium bis(trifluoromethylsulfonyl) imide BMPip[NTf2] as the latter can supply more CO2 to the microalgae than the former leading to enhanced organism growth.

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.

Like other enabling technologies, ultrasonication has moved progressively from batch to flow conditions, which are more suitable for large-scale applications and industrial purposes. Without discussing comprehensively, the subject of sonochemistry underflow, this chapter provides some background and practical considerations with a focus on chemical synthesis in following the heading of this monograph. A deeper analysis is presented for miniaturized systems as microfluidics and machine-assisted approaches will doubtless be the future of chemistry. Ultrasound in microchannels helps to prevent clogging while enhancing considerably mass transfer. Moreover, such applications will require the design of more efficient micro-sonoreactors and an accurate control of external parameters.

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.

The use of neoteric solvents to substitute organic molecular solvents offers new opportunities to develop more environmentally friendly synthetic organic chemistry to access to new molecules, materials or processes. Most known and investigated neoteric solvents (NS) remain nowadays supercritical fluids (SCF), room temperature ionic liquids (RTILS) and deep eutectic solvents (DES). Each of them offers several advantages over organic molecular solvents but also display inherent drawbacks. In order to tackle the latter moving forward to safer and faster processes, ultrasound technology was recently coupled synergistically with these new media. These three categories of NS are hereafter briefly introduced together with their own remarkable properties permitting their use as alternative benign solvents. Insights of striking developed applications with ultrasound will be then given in order to unleash the promising potential of coupling ultrasound technology with neoteric solvents.

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.

The sound is a mechanical vibration which propagates by elasticity through matter whatever its physical state. On liquid state, an interesting and unique physical phenomenon was identified at the end of nineteenth century and designated as cavitation, which is the birth, growth and collapse of tiny gas bubbles. The intensity of bubbles occurrence and of collapse violence is very dependent on the sound frequency. The most energetic cavitation activity occurs when using ultrasound frequencies, i.e. above the upper limit of human hearing (18 kHz). The incident irradiative frequency is therefore of crucial importance leading to effects on chemical systems of physical and/or chemical nature. Several other operational parameters do also greatly influence the cavitation process and are here described as well as most frequent types of ultrasonic devices working either on direct or indirect mode. ‘Hotspot’ theory and generally admitted reacting zones establishing rules of sonochemistry are also examined. Finally, some guidelines for good experimental use of ultrasonic devices are tentatively established by authors based on their own experience.

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Nowadays, the requirement for process intensification in the chemical industry no longer only meets the economic considerations but also at the necessity to anchoring the industrial production in a sustainable approach, cleaner and more energy efficient technology. As we have seen in previous chapters, the phenomenon of cavitation, whether of hydrodynamic or ultrasonic origin, is likely to generate beneficial effects recognized as conducive for scale-up operations. Technically, the extrapolation of laboratory experiments on an industrial scale consists in taking into account the numerous constraints related to the production of large quantities of materials (impurities of the raw materials, duration of process, reliability, etc.) in large reactors. Thus, the development of a production line requires the realization of a pilot unit that will solve the problems encountered during the climb to scale-up. These miniaturized replicas have variable production capacities ranging from kilogram to several tens of kilograms and can be carried out in a research unit. Therefore, many laboratories have been engaged in this way for a few years and the number of publications on pilot units, whether dedicated to ultrasonic or hydrodynamic processes, has considerably increased these last years. This chapter is meant to be didactic and is not the object of a detailed development of cavitation phenomenon scaling operations. In this sense, he is interested in the basic considerations of cavitation phenomena on the industrial scale through some reminders and representative examples.

The application of ultrasound waves to induce and enhance chemical reactivity dates back to the pioneering studies by Richards and Loomis in the late 1920s. The long journey, now entering the twenty-first century, has been accompanied by decades of low and high research activity. But arguably, the marriage between synthesis, organic synthesis in particular, and sonochemistry has been especially fruitful from the 1980s onwards. We now realize the pluses conveyed by sonication, in terms of efficiency, acceleration and selectivity. Mechanistic switching and/or different product distribution relative to non-irradiated conditions also represent salient features observed frequently in sonochemical reactions. This chapter summarizes a series of fundamental ideas in organic sonochemistry and introduces the subject within the framework of green chemistry and sustainability. Representative examples gathered in recent literature help to appreciate the added value of sonochemistry as tool.

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...

A promising method of Carbon dioxide (CO2) valorization is to use green microalgae photosynthesis to process biofuel. Two Phase Partitioning Bioreactors (TPPBR) offer the possibility to use non-aqueous phase liquids (NAPL) to enhance CO2 solubility; thus making CO2 available to maximize algae growth. This requires relatively less toxic hydrophobic Ionic Liquids (ILs) that comprise a new class of ionic compounds with remarkable physicochemical properties and thus qualifies them as NAPL candidates. This paper concerns the synthesis of ILs with octyl and butyl chains as well as different cations containing aromatic (imidazolium, pyridinium) and non-aromatic (piperidinum, pyrrolidinium) rings for CO2 absorption studies. The authors measured their respective toxicity levels on microalgae species, specifically, Scenedesmus quadricauda, Chlorella vulgaris and Botryococcus braunii. Results revealed that octyl-based ILs were more toxic than butyl-based analogues. Such was the case for bmim-PF6 at double saturation with an absorbance of 0.11, compared to Omim-PF6 at 0.17, bmim-NTf2 at 0.02, and Omim-NTf2 at 0.14, respectively. CO2 uptake results for ILs bearing octyl-based chains compared to the butyl analog were 54% (nCO2/nIL) (i.e., moles of CO2 moles of IL) and 38% (nCO2/nIL), respectively. Conclusively, 1-butyl-1-methylpiperidinium absorbed 13% (nCO2/nIL) and appeared the least toxic, having an absorbance of 0.25 at 688 nm (double saturation at 7 d) compared to 1-butyl-3-methylimidazolium, which showed the highest toxicity with zero absorbance. Accordingly, these findings suggest that 1-butyl-1-methylpiperidinium is capable of transporting CO2 to a system containing green microalgae without causing significant harm; thus allowing its use in TPPBR technology.

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

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.

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.

One-step absolute solvent-free acid-catalyzed mechanical depolymerization of pine sawdust (PSD) and commercially available α-cellulose to water-soluble sugars was carried out using ball milling. For comparison purposes, the commonly reported “solvent-free” mechanocatalytic depolymerization of lignocellulose method, which normally involves three steps (acid impregnation in solvent, vacuum drying, and mechanical depolymerization of lignocellulose), was performed. The 3,5-dinitrosalicylic acid (DNS) method was used to measure the total reducing sugar (TRS) of the obtained sugar solution, and major monosaccharides in the solution were analyzed by capillary electrophoresis (CE). More than 90% of the PSD became water-soluble through milling. Furthermore, most of the PSD was converted into TRS in approximately 30 min, and the highest TRS yield obtained was 31%, based on the dry mass. Interestingly, the TRS solutions obtained from the processed PSD were much darker than those obtained from α-cellulose due to the chromophores that formed during the depolymerization of lignin.

Development of a simple route for the catalytic conversion of starch-based industrial waste (potato peels) and potato starch into reducing sugars was investigated in two ionic liquids for comparison – 1-allyl-3-methylimidazolium chloride [AMIM]Cl and 1-(4-sulfobutyl)-3-methylimidazolium chloride [SBMIM]Cl. Over a two hour period, a 20 wt% solution containing up to 43% and 98% of reducing sugars at low temperature in aqueous [SBMIM]Cl was achieved for the starch-based waste and the potato starch, respectively. In addition, the use of microwave and low frequency ultrasound to perform the depolymerisation of the raw starch-based material was explored and compared with conventional heating processes. peerReviewed