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In order to prevent common hypersensitivity reactions to paclitaxel injections (Taxol), we previously reported an ionic liquid-mediated paclitaxel (IL-PTX) formulation with small particle size and narrow size distribution. The preliminary work showed high PTX solubility in the IL, and the formulation demonstrated similar antitumor activity to Taxol, while inducing a smaller hypersensitivity effect in in vitro cell experiments. In this study, the stability of the IL-PTX formulation was monitored by quantitative HPLC analysis, which showed that IL-PTX was more stable at 4 °C than at room temperature. The in vivo study showed that the IL-PTX formulation could be used in a therapeutic application as a biocompatible component of a drug delivery system. To assess the in-vivo biocompatibility, IL or IL-mediated formulations were administered intravenously by maintaining physiological buffered conditions (neutral pH and isotonic salt concentration). From in vivo pharmacokinetics data, the IL-PTX formulation was found to have a similar systemic circulation time and slower elimination rate compared to cremophor EL mediated paclitaxel (CrEL-PTX). Furthermore, in vivo antitumor and hypersensitivity experiments in C57BL/6 mice revealed that IL-PTX had similar antitumor activity to CrEL-PTX, but a significantly smaller hypersensitivity effect compared with CrEL-PTX. Therefore, the IL-mediated formulation has potential to be an effective and safe drug delivery system for PTX.

Crude oil palm biomass (OPB) residue is an important source of lignocellulose and could be transformed into biofuels through thermochemical conversion for heat and power in CHP plants or act as sustainable reinforcement in the biocomposite industry. Effective pretreatment is an essential task for the utilization of waste biomass for bioenergy and biomaterials. The comparative effect of two ionic liquids (ILs), 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) and 1-ethyl-3-methylimidazolium diethylphosphate ([emim[dep]), on OPB pyrolysis kinetic and thermodynamic parameters was studied using thermogravimetric analysis (TGA) coupled with Coats-Redfern integral method. The OPB residue was pretreated with ILs [bmim][Cl] and [emim][dep] under mild processing conditions of 90 °C for 3 h and was also subjected to three other conventional pretreatment methods called dilute acid, alkaline, and hot compressed water to better understand and compare the performance of ILs for pretreatment of lignocellulosic OPB. Results reveal that ILs pretreatment was superior in terms of delignification of OPB and produced the cellulose-rich fiber with 48.2% and 41.2% cellulose compared to cellulose fraction of 26.4% for the untreated sample. The values of apparent activation energies were found to be 81.8, 90.9, 92.0, 84.9, 83.8, and 93.5 kJ/mol for untreated, [bmim][Cl], [emim][dep], dilute acid, base, and hot compressed water pretreatments respectively. Further calculation of thermodynamic parameters led to the change in Gibb's free energy (ΔG°) values of 188.9, 208.0, 210.9, 219.1, 217.4 and 217.1, kJ/mol for untreated, [bmim][Cl], [emim][dep], dilute acid, base, and hot compressed water pretreatments respectively. The higher change in entropy (ΔS°) values of ILs-pretreated fibers compared to the untreated one showed that dissolution and regeneration from ILs solution had unlocked the complex 3D structure of lignocellulose, resulting in increased disorder. The results plainly revealed that ILs-based pretreatment could be a promising and environmentally benign technology for efficient utilization of agricultural residues in the fields of biofuels and biocomposite materials.

Formulations based on conventional surfactants and organic solvents have been used as potential dispersants for oil-spill remediation. However, their toxicity restricts their usage in marine environments. As a low-toxicity alternative, in this article we report an oil dispersant based on a binary mixture of an ionic liquid surfactant, choline laurate ([Cho][Lau]), and a biosurfactant, lactonic sophorolipid. We investigated the micellar properties, including the critical micelle concentration, micellar interaction parameter (β), and activity coefficients (f1 and f2) for the mixed surfactant system. A non-ideal and synergistic interaction between [Cho][Lau] and lactonic sophorolipid was observed. A stable oil-in-water emulsion formed at an optimal ratio of 40:60 (w/w) of [Cho][Lau] and lactonic sophorolipid. At this ratio, a dispersion effectiveness of 83% was achieved with a dispersant-to-oil ratio of 1:25 (v/v). We observed the dispersed oil droplets with an optical microscope and evaluated their size using dynamic light scattering. The droplet size decreased with increasing dispersant-to-oil ratio. We also assessed the toxicity of the binary surfactant mixture in zebra fish (Danio rerio). Based on this assessment, the mixture can be classified as non-toxic. Therefore, the mixture of [Cho][Lau] and lactonic sophorolipid is a potential alternative to conventional toxic oil-spill dispersants.

The technological utility of active pharmaceutical ingredients (APIs) is enormously improved when they are converted into ionic liquids (ILs). API-ILs possess better aqueous solubility and thermal stability than that of solid-state salt or crystalline drugs. However, many such API-ILs are not biocompatible or biodegradable. In the current study, we synthesized a series of IL-APIs using methotrexate (MTX), a potential anticancer prodrug, and biocompatible IL-forming cations (choline and amino acid esters). The MTX-IL moieties were characterized through 1H NMR, FTIR, p-XRD, DSC and thermogravimetric analysis. The solubility of the MTX-ILs was evaluated in simulated body fluids (phosphate-buffered saline, simulated gastric, and simulated intestinal fluids). An assessment of the in vitro antitumor activity of the MTX-ILs in a mammalian cell line (HeLa cells) was used to evaluate their cytotoxicity. The MTX-ILs showed aqueous solubility at least 5000 times higher than that of free MTX and two orders of magnitude higher compared with that of a sodium salt of MTX in both water and simulated body fluids. Importantly, a proline ethyl ester MTX prodrug showed similar solubility as the MTX sodium salt but it provided improved in vitro antitumor activity. These results clearly suggest that the newly synthesized API-ILs represent promising potential drug formulations.

Oral delivery of the sparingly soluble drug methotrexate (MTX) is challenging owing to its poor bioavailability and low solubility. To address this challenge, the present study reports the conversion of MTX into a series of five ionic liquids (ILs) comprising a cationic component-i.e., cholinium (Cho), tetramethylammonium (TMA), tetrabutylphosphonium (TBP), or an amino acid ester-and an anionic component-i.e., MTX. The biocompatibility, pharmacokinetics, tissue distribution, and antitumor efficacy of each MTX-based IL were investigated to determine its usefulness as a pharmaceutical. Oral administration to mice revealed that proline ethyl ester MTX (IL[ProEt][MTX]) had 4.6-fold higher oral bioavailability than MTX sodium, followed by aspartic diethyl ester MTX, IL[TBP][MTX], IL[Cho][MTX], and IL[TMA][MTX]. The peak plasma concentration, elimination half-life, area under the plasma concentration, mean absorption time, and body clearance of IL[ProEt][MTX] were significantly (p 0.0001) higher by 1.7-, 6.2-, 4.6-, 2.5-, and 3.6-fold, respectively, than those of MTX sodium. MTX accumulation in the lungs, spleen, kidney, and gastrointestinal tract was also reduced by 5.6-, 1.8-, 1.5-, and 1.4-fold, respectively, indicating the IL formulations had lower systemic toxicity than free MTX. Mechanistic studies revealed that the IL[ProEt][MTX] solution formed spherical structures with an average size of 190 nm. This was probably responsible for its improved oral absorption performance in vivo. In vivo antitumor studies also demonstrated that IL[ProEt][MTX] suppressed tumor growth more than MTX sodium. These results suggest that MTX-based ILs provide a simple scalable approach to improving the oral bioavailability of poorly soluble MTX.

Coronavirus disease 2019 (COVID-19) has spread across the world, and no specific antiviral drugs have yet been approved to combat this disease. Favipiravir (FAV) is an antiviral drug that is currently in clinical trials for use against COVID-19. However, the delivery of FAV is challenging because of its limited solubility, and its formulation is difficult with common organic solvents and water. To address these issues, four FAV ionic liquids (FAV-ILs) were synthesized as potent antiviral prodrugs and were fully characterized by nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared (FT-IR) spectrometry, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC). The aqueous solubility and in vivo pharmacokinetic properties of the FAV-ILs were also evaluated. The FAV-ILs exhibited improved aqueous solubility by 78 to 125 orders of magnitude when compared with that of free FAV. Upon oral dosing in mice, the absolute bioavailability of the β-alanine ethyl ester FAV formulation was increased 1.9-fold compared with that of the control FAV formulation. The peak blood concentration, elimination half-life, and mean absorption time of FAV were also increased by 1.5-, 2.0-, and 1.5-fold, respectively, compared with the control. Furthermore, the FAV in the FAV-ILs exhibited significantly different biodistribution compared with the control FAV formulation. Interestingly, drug accumulation in the lungs and liver was improved 1.5-fold and 1.3-fold, respectively, compared with the control FAV formulation. These results indicate that the use of ILs exhibits potential as a simple, scalable strategy to improve the solubility and oral absorption of hydrophobic drugs, such as FAV.

Human skin contains numerous antigen-presenting cells that are a potential target for several immune-based therapies, including vaccination and cancer immunotherapy. However, the outermost layer of the skin—the stratum corneum—acts as a major physical barrier against the permeation of antigens that have a molecular weight > 500 Da. In this study, an ionic liquid-assisted delivery system (ILDS) was developed, which enabled the successful transdermal delivery of an antigenic protein, ovalbumin (OVA), with a toll-like receptor agonist, imiquimod, as an adjuvant, to stimulate a specific immune response. Both the ionic liquids and ILDS were completely biocompatible for topical or transdermal application for therapeutic purposes. The skin permeation of the antigenic protein and adjuvant was found to be significantly enhanced because of the incorporation of a surface-active ionic liquid in the ILDS. An in vivo immunization study showed that there was a high level of OVA-specific IgG antibody production because of the enhanced permeation of the antigen and adjuvant across and into the skin. In a preclusive anticancer study, vaccination through ILDS showed stronger tumor-growth inhibition compared to control group. These results indicated that the ILDS could be a promising strategy for transdermal immunization as future therapeutics.

The conversion of palm oil into a sulfur-based polymer by copolymerization with sulfur powder at its molten state is herein reported. The obtained sulfur-containing polymer was characterized using Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to demonstrate the successful conversion. The disappearance of the peaks related to vinylic groups of oil together with the appearance of a peak representing C-H rocking vibrations in the vicinity of C-S bonds confirmed the copolymerization of sulfur with oil. TGA revealed that the polymers have thermal stability up to 230°C under nitrogen and the polymers leave 10% sulfur-rich ash. DSC proved that a small amount of elemental sulfur remained unreacted in the polymer, which showed amorphous and heavily crosslinked structure resembling thermosets. These copolymers are an environmental-friendly polymeric material promoting the utilization of the abundant sulfur while also adding value to palm oil.

Ionic liquids (ILs) have been used significantly in pharmaceutics and medicine because of their exceptional “green” properties and tailor-made physicochemical and biological properties. ILs can dissolve many important drug molecules at ambient conditions, which are sparingly soluble in water and other conventional organic solvents. However, the selection of potential ILs from thousands of anion–cation combinations is quite challenging. To address this limitation, various computation methods have been used to screen appropriate ILs for solubility and applications of a specific drug molecule. Among those methods, the conductor-like screening model (COSMO)—a continuum solvation model based on quantum chemistry—is found remarkably effective in screening suitable ILs for pharmaceutical applications due to its excellent capability in predicting physical and chemical properties. The advantage of these optimizing tools is that only the molecular structure is enough for prior predictions. Solubility, activity coefficient, selectivity, free energies, partition coefficient, and octanol–water coefficient are few properties that can be easily predicted. This chapter presents a detailed discussion on the COSMO screening of cations and anions of ILs for various applications and highlighting the advantages of this predictive tool.

The thermal kinetic modeling is crucial for development of sustainable processes where lignocellulosic fuels are a part of chemical system and their thermal degradation eventuates. In this paper, thermal decomposition of three lignocellulosic materials (bagasse, rice husk, and wheat straw) was obtained by the thermogravimetric (TG) technique and kinetics was analyzed by both model-fitting and isoconversional (model-free) methods to compare their effectiveness. Two models selected from each class include Arrhenius and Coats–Redfern (model-fitting), and Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO) (model-free). The formal model-fitting approach simulating the thermal decomposition of solids by assuming a fixed mechanism was found to be unduly facile. However, activation energy (E) values calculated from two model-fitting techniques were considerably different from each other with a percentage difference in the range of 1.36% to 7.65%. Particularly, both model-fitting methods predicted different reaction mechanism for thermal disintegration of lignocellulosic materials (two-dimensional diffusion (D2) by Arrhenius and one-dimensional diffusion (D1) by Coat–Redfern method). Conversely, the model-free routine offers a transformation of mechanism and activation energy values throughout reaction and is, therefore, more authentic to illustrate the complexity of thermal disintegration of lignocellulosic particles. Based on the model-free kinetic analysis, the lignocellulosic materials may be devised in following order of activation energy: rice husk &gt, bagasse &gt, wheat straw, by both KAS and FWO methods with a percentage difference no more than 0.84% for fractional conversion up to 0.7. Isoconversional approach could be recommended as more realistic and precise for modeling non-isothermal kinetics of lignocellulosic residues compared to model-fitting approach.

Chemical dispersants is one of the globally accepted remediation technique used for marine oil spill. However, the toxicity related with these dispersants confined its application in marine environment. Therefore, to overcome this problem, the employment of environmentally benign dispersants is one of the effective conceivable approach. In this study, the formulation comprised of choline based ionic liquid, choline laurate ([Cho][Lau]) and a biosurfactant, lactonic sophorolipids (LS) were used as a crude oil emulsifier. The toxicity of the newly developed formulation was evaluated to confirm their safe employment in sea water. The developed formulation worked effectively as a crude oil emulsifier and formed a stable crude oil emulsion. The toxicity study against Gram-positive and -negative bacteria depicts the “practically harmless” nature of the developed formulation. Thus, the results presented in this study showed that the new formulation can potentially replace the conventional dispersant used for marine oil spill remediation.

This chapter discusses the treatment of palm oil empty fruit bunch using ionic liquids (ILs) pretreatment. By mixing IL and cellulase enzyme (IL-E) in a single pot, the empty fruit bunch (EFB) was pretreated with simultaneous fermentation. Choline acetate [Ch][Ac], which has excellent biological compatibility and renewability, has been used for pretreatment. Chemical analysis, electron scanning microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the EFB and its hydrolysate. After 24 and 48 h of enzymatic hydrolysis, sugar yield improved from 0.058 g/g EFB in the crude (untreated) sample to 0.283 and 0.62 06 g/g in the IL-E phase. EFB hydrolysate demonstrates suitability for the production of ethanol (EtOH) with a yield of 0.275 g EtOH/g EFB in the presence of [Ch][Ac] without additional nutrients, compared to the low yield without IL pretreatment.

This chapter discusses the stabilization of Trichoderma ressie cellulase (Tri-Cel) in ionic liquids (ILs) to enable the in situ hydrolysis of cellulosic and lignocellulosic substances. It is well recognized that enzymes tend to lose their activities in ILs, but several methods have been used to increase or minimize the loss of activity in ILs. In this study, cellulase was therefore tested in several ILs. This approach opens an insight for further studies to discover more about the effects of ILs on cellulase and their interactions in the aqueous system. It can also offer successful manufacturing and processing of different biomass biofuels.

Ionic liquids (ILs) are a large group of so-called green solvents with extensive uses in medicine, drug delivery, stabilization of proteins and enzymes, and industrial applications. Active Pharmaceutical Ingredients ionic liquids (API-ILs) are the third generation of ILs. Because of their role precision, biodegradability, and biocompatibility, this class of ILs is gaining interest. This chapter, therefore, aims to recognize the antimicrobial action of non-toxic and biocompatible antibiotics targeting API-ILs that could respond to resistant strains. The World Health Organization (WHO) has published a priority list of pathogens for antibiotic research and development. Among the pathogens are Enterobacteriaceae (Escherichia coli, Klebsiella pneumonia, Serratia spp., Enterobacter spp., Proteus spp., Providencia spp, and Morganella spp), carbapenem-resistant, 3rd generation cephalosporin-resistant, Pseudomonas aeruginosa (carbapenem-resistant), and Acinetobacter baumannii (carbapenem-resistant). The application of API-ILs could assist in overcoming the challenges correlated to the pharmaceutical industry including drug solubility and polymorphism. At present, biocidal characteristic of large cations, such as imidazolium and benzalkonium species are mostly utilized to hinder growth of yeast or bacteria. In this context, this chapter introduces a background on the applications of ILs as antimicrobial agents for microbial resistance. Their corresponding mechanism of ILs and their effect as an antimicrobial agent was investigated, as well. Since the selection of the organic cations and anions in the ILs formulation can tube the biological properties of the ILs, we aim to unveil some of the recent studies that focused on the antimicrobial activities of ILs toward some resistant strains.

Heavy metals are high atomic weight elements that consist five times higher density than water. The widespread use of heavy metals in scientific, agricultural, domestic, industrial, and medical applications accelerated their distribution into water bodies through the environment. The extreme toxicity of heavy metals and their adverse effects on human health have raised concerns for the removal of heavy metals from different water bodies. Considering the severe toxicity, mercury, cadmium, chromium, arsenic, and lead were identified as priority heavy metal pollutants and categorized as human carcinogens by United States Environmental Protection Agency. Over the past few years, zerovalent iron nanoparticles have emerged as potential alternatives for the removal of heavy metals from water and wastewater streams. The superior reactivity and large surface area of zerovalent iron nanoparticles provided greater versatility for the in situ remediation of heavy metals. Therefore, this chapter presents a detailed discussion on the advances reported for the heavy metal remediation using zerovalent iron nanoparticles. It begins with the fate and transport of heavy metals into water bodies and their impact on human health and environment. Additionally, preparation methods, characterization techniques, and inherent applications of zerovalent iron nanoparticles toward the removal of heavy metals from different water bodies are extensively described following the risk assessment studies. Finally, concluding remarks and future prospects that support the effective remediation of heavy metals using zerovalent iron nanoparticles are summarized.

Ionic liquids (ILs) are regarded as green solvents and have demonstrated ability in the solvation of lignocellulosic material, thus promoting its enzymatic hydrolysis by cellulases. In this study, ...

Polychlorinated biphenyls (PCBs) are a class of synthetic organic compounds containing carbon, hydrogen and chlorine atoms. They have been used in various industrial and commercial applications owing to their high boiling points, non-flammability, chemical stability and insulating properties. Also, PCBs are exceptionally stable and prevail in the environment for a very long time. Consequently, they may not just affect the individual organisms, but ultimately the entire ecosystems. The present review describes the sources, fate and transport of PCBs in the environment followed by their accumulation in humans, animals, plants and biota. We provide the description of current knowledge on sampling, pretreatment and cleanup procedures for the best extraction of PCBs from various contaminated sites. Further, the futuristic analytical strategies established for the determination of PCBs and adequate remedial methods are discussed in detail. Also, the analytical challenges and recommendations for future research regarding the PCBs assessment in the environment are summarized. Overall, this review presents comprehensive knowledge on cutting edge technologies available in the field of PCBs analysis.

Chemical dispersants are globally accepted response option for marine oil spill remediation. However, their toxicity reduces its employment in sea environment. To address this limitation, the use of environmentally benign dispersants is the best possible approach. In this research, the antimicrobial activity and fish toxicity of environmentally benign dispersants comprise of binary mixture of choline based ionic liquids, i-e; choline myristate ([Cho][Mys]) and choline oleate ([Cho][Ol]) using water as a solvent were investigated to ensure their safe use in marine environment. The antimicrobial activity at their 50% effective concentrations (EC50) against Gram-positive and -negative bacteria illustrates that all the mixed binary system can be classified as “practically harmless”. The half-lethal concentration, LC50 on zebra fish (Danio rerio) also revealed that the studied mixed surfactant system could be ranked as ‘non-toxic’. The results presented in this research indicates that the dispersant comprise of binary mixture of [Cho][Mys] and [Cho][Ol] could potentially replace the toxic marine spill dispersants

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.

The transdermal delivery of sparingly soluble drugs is challenging due to of the need for a drug carrier. In the past few decades, ionic liquid (IL)-in-oil microemulsions (IL/O MEs) have been developed as potential carriers. By focusing on biocompatibility, we report on an IL/O ME that is designed to enhance the solubility and transdermal delivery of the sparingly soluble drug, acyclovir. The prepared MEs were composed of a hydrophilic IL (choline formate, choline lactate, or choline propionate) as the non-aqueous polar phase and a surface-active IL (choline oleate) as the surfactant in combination with sorbitan laurate in a continuous oil phase. The selected ILs were all biologically active ions. Optimized pseudo ternary phase diagrams indicated the MEs formed thermodynamically stable, spherically shaped, and nano-sized (&lt, 100 nm) droplets. An in vitro drug permeation study, using pig skin, showed the significantly enhanced permeation of acyclovir using the ME. A Fourier transform infrared spectroscopy study showed a reduction of the skin barrier function with the ME. Finally, a skin irritation study showed a high cell survival rate (&gt, 90%) with the ME compared with Dulbecco&rsquo, s phosphate-buffered saline, indicates the biocompatibility of the ME. Therefore, we conclude that IL/O ME may be a promising nano-carrier for the transdermal delivery of sparingly soluble drugs.

Shale instability due to hydration and swelling is an unavoidable problem during hydraulic fracturing or drilling with water-based fluids. In this study, 1-butyl-3-methylimidazolium chloride (BMIMCl) an ionic liquid was utilized as a clay swelling inhibitor. The performance of BMIMCl was evaluated by the bentonite plate soaking test and linear swelling test. FT-IR and zeta potential test was done to explain the swelling inhibition mechanisms. Moreover, XRD test was conducted for the characterization of bentonite (swelling clay). 2 wt.% BMIMCl reduced the swelling rate of bentonite by 19.38% while the conventional and mostly used inhibitor, 3 wt.% KCl reduced 13.84% compared with distilled water. These results showed that BMIMCl has better inhibitive properties than the most used clay stabilizer, KCl. This inhibitor showed better performance because of the presence of a hydrophilic head and hydrophobic tail in its structure. The hydrophilic positive head helped it to get adsorbed on the bentonite surface, forming hydrogen bonds, and reduced the surface negative charge. On the other side, the butyl chain may be made a hydrophobic shield that prevented water from entering into the interlayer space. The ability of BMIMCl to form bonds with bentonite and water was confirmed by FT-IR analysis. Therefore, BMIMCl has the potential to be an effective shale swelling inhibitor during drilling and hydraulic fracturing operations in the water-sensitive shale formation.

Ionic liquids (ILs) have gained great attention as potent solubilizing agents of poorly soluble bioactive compounds. The use of Luteolin (LUT) – a natural bioactive compound – is limited because of its poor aqueous solubility. To address this issue, this study reports potential ionic liquids (ILs) for effectively solubilizing LUT at ambient temperature. First, promising ILs were screened from a potential 180 ILs that were proposed by the combination of 20 standard amino acid ethyl esters cations and nine phenolic acids anions using the conductor-like screening model for real solvents (COSMO-RS); the activity coefficients of LUT at infinite dilution in ILs were used as the screening criteria. Four proline ethyl ester phenolate ILs (PEEP-ILs) composed of a biocompatible proline ethyl ester and bioactive phenolic acids (trans-ferulic, vanillic, p-coumaric, and 4-hydroxybenzoic acid) were selected and synthesized. The synthesized PEEP-ILs were characterized through 1H NMR, FT-IR, elemental analysis, TGA, and DSC. The experimental solubility of LUT in PEEP-ILs (60% IL in water) showed excellent solubility. Among the PEEP-ILs, proline ethyl ester ferulate (IL[ProEt][Fer]) exhibited the best LUT solubility, followed by ILs with p-coumarate (IL[ProEt][Cou]), vanillate (IL[ProEt][Van]), and 4-hydroxybenzoate (IL[ProEt][Ben]). 1H NMR assessment and COSMO-RS prediction confirmed that the ILs facilitated the solubilization of LUT through multiple hydrogen bonding, π−π, and cation−π interactions between the LUT and the ILs. The biocompatibility study revealed that PEEP-ILs were relatively harmless and low toxicity compared with conventional imidazolium, pyridinium, pyrrolidinium, piperidinium, and morpholinium-based ILs. The LUT dissolved in the newly-synthesized PEEP-ILs and demonstrated better organoleptic properties on red apple slices. These results indicate that PEEP-ILs can be potential green alternatives to conventional toxic solvents for dissolving poorly water-soluble bioactive natural preservatives.

Phytosynthesis of gold nanoparticles (AuNPs) have shown the tremendous interest owing to their ecofriendly, simple, cost effective and renewable features. The growth kinetics behavior of plants mediated AuNPs is relatively scarce despite the significant impacts of their morphological structures on their performance in various fields of sciences. Herein, AuNPs were synthesized employing aqueous Elaeis guineensis leaves extract and characterized using TEM, UV–vis spectroscopy and DLS. Ostwald ripening (OR) and Orientation attachment (OA) models were used to investigate the mechanisms leading towards the growth of AuNPs as function of time. The changes in the positions of UV–vis spectra peaks and increasing number of agglomerated particles as function of time detected the ongoing growth process of AuNPs. The experimental results exhibited that the growth of AuNPs was mainly governed by the OA kinetics in initial phase owing to the stable surface adsorption of phenolic compounds, flavonoids, carboxylic acids and amides, impeding the diffusion-controlled growth. Moreover, TEM analysis also confirmed the domination of OA mechanism in early stage through displaying the formation of AuNPs with quasi spherical and elongated morphology. However, the OA growth kinetics was found to be majorly substituted and followed by the OR mechanism in the later period.

In the present study, a sensitive and fully validated liquid chromatography with mass spectrometry method was developed for the quantification of three potential genotoxic impurities in rabeprazole drug substance. The separation was achieved on Symmetry C18 column (100 × 4.6 mm, 3.5 μm) using 0.1% formic acid in water as mobile phase A and acetonitrile as mobile phase B in gradient elution mode at 0.5 mL/min flow rate. Triple quadrupole mass detection with electrospray ionization was operated in selected ion recording mode for the quantification of impurities. The calibration curves were demonstrated good linearity over the concentration range of 1.0-4.5 ppm for O-phenylenediamine, 1.8-4.5 ppm for 4-nitrolutidine-N-oxide and 1.0-4.5 ppm for benzyltriethylammonium chloride with respect to 10 mg/mL of rabeprazole. The correlation coefficient obtained in each case was >0.998. The recoveries were found satisfactory over the range between 94.22 and 106.84% for all selected impurities. The method validation was carried out following International Conference on Harmonization guidelines, from which the developed method was able to quantitate the impurities at 1.0 ppm for O-phenylenediamine, 1.8 ppm for 4-nitrolutidine-N-oxide and 1.0 ppm for benzyltriethylammonium chloride. Furthermore, the proposed method was successfully evaluated for the determination of selected impurities from bulk drug and formulation samples of rabeprazole within the acceptable limits.

Ionic liquid (IL) surfactants have attracted great attention as potential alternatives to conventional surfactants because of their unique tailor-made physicochemical properties. However, in most cases, the aggregations formed by single IL surfactants in aqueous media are unstable, even when using a large amount of surfactant. To address this limitation, here we investigated the aggregation behavior of binary IL surfactant micelles composed of the ILs choline oleate ([Cho][Ol]) and choline laurate ([Cho][Lau]) in aqueous media using tensiometry and dynamic light scattering measurements. Micellar and interfacial parameters including critical micelle concentration (cmc), micellar interaction parameters (β), activity coefficients (f1 and f2), surface excess concentration (Гmax), minimum surface area per molecule (Amin), and the size of surfactant aggregates were studied. In addition, various thermodynamic parameters such as the Gibbs free energy of micellization (∆Gomic), standard Gibbs free energy of adsorption (∆Goad), molar free energy (Gmin), and the excess Gibbs free energy of micellization (ΔGex) were also evaluated. A non-ideal synergistic interaction was observed for the mixed IL surfactant system, which formed larger micelles (105–120 nm) compared with those formed with a single IL (86–102 nm). The formed micelles were found to be thermodynamically stable with regards to all the mole ratio of ILs system. The antimicrobial activity of the single as well of the mixed IL system against Gram-positive and -negative bacteria displayed a low toxicity profile that fell in the range of “practically harmless” (100–1000 mg L−1). The results suggested that the micellar system composed of mixed IL surfactants provides unique physical, chemical, and biological properties may offer novel opportunities for various applications such as oil dispersants.

The particles size is an influential factor to control the optical, physicochemical, and electronic properties of gold nanoparticles (AuNPs). Any variation in the particles size can change these properties that not only confine the scope of AuNPs but also diminish the colloidal stability of solution. In this work, AuNPs are synthesized using ionic liquid mediated oil palm leaves (OPL) extract and their colloidal stability, interparticle interactions and catalytic performances as a function of time are investigated. Various analytical techniques such as GC–MS, UV–vis spectrophotometer, DLS and FESEM analyses were utilized to explain the different phases involved in bio- synthesis of AuNPs. In addition, synthesized AuNPs of different ages were used for catalytic degradation of methylene blue (MB) to examine their catalytic performance as a function of time. Moreover, the qualitative techniques including reduction of absorbance, variation in surface plasmon resonance (SPR) peaks, change of particles size and zeta potential were used to endorse the colloidal stability of AuNPs. Furthermore, an analytical method was established by considering particles’ interaction as described by Derjaugin-Landau-Verwey-Overbeek’s theory to establish a quantitative definition of stability. Finally, the values of hydrodynamic particles size and zeta potential were fitted to estimate stability ratio of AuNP which provided precise indication of the colloidal stability. The respective reaction rate constants of AuNPs for degradation of MB were found to be 0.272 and 0.258 min−1 after day 1 and day 60 respectively, indicating an efficient activity of these particles for an extended period of reaction time.

The technological utility of active pharmaceutical ingredients (APIs) is greatly enhanced when they are transformed into ionic liquids (ILs). API-ILs have better solubility, thermal stability, and the efficacy in topical delivery than solid or crystalline drugs. However, toxicological issue of API-ILs is the main challenge for their application in drug delivery. To address this issue, 11 amino acid esters (AAEs) were synthesized and investigated as biocompatible counter cations for the poorly water-soluble drug salicylic acid (Sal) to form Sal-ILs. The AAEs were characterized using 1H and 13C NMR, FTIR, elemental, and thermogravimetric analyses. The cytotoxicities of the AAE cations, Sal-ILs, and free Sal were investigated using mammalian cell lines (L929 and HeLa). The toxicities of the AAE cations greatly increased with inclusion of long alkyl chains, sulfur, and aromatic rings in the side groups of the cations. Ethyl esters of alanine, aspartic acid, and proline were selected as a low cytotoxic AAE. The cytotoxicities of the Sal-ILs drastically increased compared with the AAEs on incorporation of Sal into the cations, and were comparable to that of free Sal. Interestingly, the water miscibilities of the Sal-ILs were higher than that of free Sal, and the Sal-ILs were miscible with water at any ratio. A skin permeation study showed that the Sal-ILs penetrated through skin faster than the Sal sodium salt. These results suggest that AAEs could be used in biomedical applications to eliminate the use of traditional toxic solvents for transdermal delivery of poorly water-soluble drugs.

This paper presents the spatial variability of reasonable government rebates for rainwater tanks installations with a case study for the largest Australian city, Sydney. Five different rain-gauge stations are selected around different regions covering Sydney metropolitan area. An earlier developed daily water balance model (eTank) is used considering five average years’ rainfall data as an input for each region. It is shown that significant variations among the regions are expected in regards to rainwater savings; even with the same tank size, same roof connection and same rainwater demand, south-east region saves more water than that of west and north regions. Also, region having lowest annual rainfall is not necessarily having lowest rainwater savings potential. Also, in regards to water savings efficiency, region having highest annual rainfall may not render highest water savings efficiency. Providing a double-sized tank or double sized roof is likely to increase the savings only up to 1.29 times. It is found that the payback periods of total rainwater tank related costs widely vary depending on region, tank, roof and demand scenario; a variation from 20 to 90 years without government rebate is expected. However, with reasonable government rebates these payback periods can be brought down to 8 years. To optimise government’s spending a variable rebate scheme can be introduced based on the current findings.

In the last decade, development of bioinspired protocols to synthesize gold nanoparticles (AuNPs) using plants and their extracts have been dealt by researchers due to their low cost, renewability and non-toxic features. A simple, cheap and ecofriendly method is reported to synthesize stabilized AuNPs of size 35–75 nm at room temperature using aqueous Elaeis guineensis (oil palm) leaves extract without addition of any external agent. Oil palm leaves mediated AuNPs were characterized using FTIR, UV–vis spectrophotometer, EDAX, XPS, FESEM, TEM, DLS and TGA. FTIR spectra results revealed contribution of phenolic, carboxylic, amines and amides in reduction of trivalent gold ions and stabilization of formed gold atoms. Reaction solution color change and UV–vis spectra confirmed reduction of gold ions to generate gold atoms. Reaction mechanism explained the role of phenolic compounds in reduction reaction using FTIR and UV–vis spectra results. EDAX and XPS results further validated the formation of metallic gold particles through bioreduction of gold ions. Crystal structure of metallic gold particles was confirmed through XRD peaks indexing to (111), (200), (220) and (311) planes. TEM and FESEM particles size measurements exhibited the formation of nanostructured AuNPs. Synthesis of well scattered and spherical shaped AuNPs was revealed through FESEM and TEM images. The excellent stability of AuNPs was shown through high negative zeta potential value (−14.7 ± 4.68 mV) and uniform dispersion in aqueous media. Our results disclosed the excellent potential of Elaeis guineensis (oil palm) leaves as reducing and stabilizing agents in green synthesis of well scattered spherical shaped AuNPs, which can be employed as strong candidates in medical drug delivery and industrial applications.

Ionic Liquid (ILs) in oil microemulsions (IL/O MEs) have emerged as a potential carrier for transdermal drug delivery, particularly for sparingly soluble drug molecules, such as acyclovir and methotrexate. However, less attention was paid in the selection of non-toxic and biodegradable ILs. In this paper, we report new IL/O MEs with ammonium acetate ILs, which can dissolve acyclovir and methotrexate significantly. Microemulsions were composed of a mixture of nonionic surfactants, polyoxyethylene sorbitan monooleate (Tween-80), and sorbitan laurate (Span-20)/ILs/oil isopropyl myristate (IPM). Three ILs called 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]), triethylammonium acetate ([TEA][OAc]) and diethylammonium acetate ([DEA][OAc]) were selected due to their non-toxic property. Based on the pseudo-ternary diagrams constructed, it was evident that Span-20 played the key role as a surfactant while Tween-80 acted as the co-surfactant, showing optimal dissolution of the ILs into the system prepared with a ratio of 1:3 (Tween 80:Span20). This binary mixture also depicted the lowest viscosity, which is favorable as a carrier agent in drug delivery. The incorporation of various ILs into microemulsions resulted in a particle size ranging from 11 to 39.7 nm at diverse drug loading capacity. The formulation with IL [TEA][OAc] and IL [DEA][OAc] displayed substantial drug carrying capacity and stability compared to the commercially available IL [EMIM][OAc] loaded system.

Biosynthesis of gold nanoparticles (AuNPs) using plant extracts has been receiving considerable attention of researchers due to their environmental friendly, low cost and renewability features. AuNPs were successfully synthesized at ambient conditions using aqueous Elaeis guineensis (oil palm) leaves extract without addition of any chemical agent. UV-Vis spectrophotometer, DLS and TEM were used to characterize the phytosynthesized AuNPs. FTIR was carried out to identify the functional groups involved in reduction of gold ions and stabilization of AuNPs. Hydrodynamic diameter was found to be reduced from 69± 39.80 nm to 55.22 ± 42.86 nm with an increase in the volume of gold chloroauric acid (1.53 mM) from 1.0 mL to 2.0 mL with fixed volume of oil palm leaves extract respectively. Size enlargement was observed from 60 ±43.76 nm to 123.5 ±110 nm with further increase in the volume of gold chloroauric acid from 3.0 mL to 5.0 mL respectively. Zeta potential (surface charge) of AuNPs was found to be reduced from -20 ± 6.80 mV to -15 ± 6.15 mV with an increase in the volume of gold chloroauric acid from 1.0 mL to 5.0 mL respectively. TEM results showed the formation of well scattered spherical, triangular and nonspherical shaped AuNPs by using 3.0 mL of gold chloroauric acid with an average particle diameter of 36.84 ± 9.0 nm. FTIR results revealed the role of phenolic, carboxylic and amides functional groups in reduction of gold ions to form AuNPs and their stabilization. Hence, ploydisperse AuNPs synthesized using Elaeis guineensis (oil palm) leaves with alterable morphology and good stability can be efficiently employed in medical and industrial applications. © Universiti Malaysia Pahang, Malaysia.

Development of ionic liquid-based emulsion membranes (ILEMs) has emerged as potential alternatives to organic solvent-based emulsion membranes for the extraction and recovery of biologically active compounds from aqueous streams. Hence, present study aims to develop novel ILEMs for the removal of bioactive lactic acid (LA) from aqueous streams using 100% vegetable oil as diluent. A series of ILEMs were prepared using three different ionic liquids (ILs) namely tetramethylammonium chloride [TMAm][Cl], tetramethylammonium acetate [TMAm][Ac] and tributylmethylammonium chloride [TBMAm][Cl] as a carrier. Besides, olive oil used as diluent, NaOH used as stripping agent, Tween 80 and Span 20 were employed as emulsifier in ILEMs preparation. The visual static stability of ILEMs was observed and the ILEM extraction efficiency was fully optimized in terms of various process parameters. The results showed that short-chain acetate based quaternary ammonium IL [TMAm][Ac] provided greater efficiency compared to chloride based ILs [TMAm][Cl] and [TBMAm][Cl]. A maximum of 94.50% LA removal was obtained with [TMAm][Ac] at optimized conditions of 0.05 M LA, 1.0 wt.% Span 20, 0.3 M NaOH, 0.3 wt.% [TMAm][Ac], 0.3 ratio of internal phase to diluent phase and 3:1 treat ratio (ratio of external phase to membrane phase) at a stirring speed of 250 rpm for 25 min. The emulsion was found stable for 134 min at the optimized conditions. Overall, this newly developed ILEM could be effectively used for the LA removal and other bioactive compounds from aqueous streams.

Surface-active ionic liquids (SAILs) are receiving growing interest as environmentally friendly designer surfactants for various applications, including drug formulation and delivery. The use of SAILs in the pharmaceutical industry has the potential to address the challenges associated with conventional surfactants. The tunable formation of complementary ion pairs from a diverse range of ions enables the task-specific optimization of SAILs. SAILs comprising second and third-generation cations and anions have been used to design biocompatible self-assembled systems including micelles, microemulsions, vesicles, liposomes, and nanoparticles for drug delivery carriers. Compared with conventional surfactant-based carriers, SAIL-based systems offer better pharmacokinetic and pharmacodynamic properties. This mini-review highlights recent findings on the formation of ionic liquid-based self-assembled systems and their potential applications in drug delivery.

Ionic liquids (ILs) - as environmentally friendly “green” solvents- have been progressively used in various reactions as reagents, solvents and co-solvents including lipase-catalysed reactions. In fact, lipase-catalysed reactions in ILs are considered as a “green”-reaction and are more advantageous than chemical methods owing to the easy recovery of the product and the mild conditions of the reactions. The use of lipase in ILs provides many technological advantages compared to conventionally used solvents, such as selectivity enhancement, enzyme stability improvement, higher conversion rate, and better recyclability and recovery system. Nevertheless, in some cases, especially in hydrophilic ILs, lipase exhibits activity reduction when compared with organic solvents. Currently, various attempts have been made to enhance the performance of lipases in ILs. The main objective of this review is to demonstrate recent developments in the technology of using ILs as reaction media for lipase. It is expected that this review might be an inspiration in ILs assisted lipase-catalysed reactions to produce value-added materials including biofuels as well as biodiesel.

The employment of chemical dispersants for oil spills is a universally accepted response option. However, the toxicity associated with chemical dispersant restricts its usage in marine environments. The toxicity of these dipersants can be minimized by utilizing biodegradable and enviromentally benign surfactants. In addition, the use of water in their formulation further reduces its toxicity. In this study, the ability of choline based Ionic Liquids (choline laurate and choline oleate) solubilized in water to disperse crude oil were analyzed. Results presented in this study showed that an effective dispersant is obtained by combining these two amphiphilies. For maximum dispersion, the optimal choline laurate and choline oleate ratio used is 50:50 (w/w). The dispersion efficiency of 67% was achieved by employing this optimal combination with dispersant to oil ratio (DOR) of 1:10 (v/v). The interfacial activity of the combined system was also investigated and it was observed that the interfacial activity of the combined system is greater than individual components.The results presented in this study suggests that the blend of choline laurate and choline oleate could potentially replace the conventional toxic oil spill dispersants.

Chemical oil spill dispersants are toxic to the marine environment, spurring a search for environmentally friendly dispersant formulations. We have formulated an oil spill dispersant composed of two biocompatible surfactants, Tween 80 (T) and surface-active ionic liquid (SAIL), [BMIM] [Lausar] (1-butyl-3-methylimidazolium lauroyl sarcosinate). Various micellar, interfacial, and thermodynamic properties of Tween 80 and ionic liquid (T/IL) blends were studied. The T/IL blends were solubilized in simulated seawater, and their oil (light Arab crude oil) dispersion effectiveness was determined by the baffled flask test. A synergistic interaction was observed between T and IL, such that a blend is effective as an oil dispersant, but neither is effective on its own. The stability of crude oil droplets was maximized at a 40/60 (w/w) of T/IL. The dispersion effectiveness at this specific ratio was found to be 81.19%, with a dispersant to oil ratio (DOR) of 1:25 (volume). The size and size distribution of dispersed oil droplets at function of DOR were investigated using optical microscopy and particle size analyzer. The results showed that the sizes of oil droplets decreased with DOR. We conclude that T/IL blends have unique properties which make them viable alternatives for oil spill remediation.

Converting agricultural lignocellulosic waste into marketable composite product is a promising approach to protect the environment and earn financial gain. Ionic liquids (ILs) have emerged as the innovative and effective solvents for pretreatment of lignocellulosic materials to produce potential reinforcements for biocomposite manufacturing. Kinetic predictions are particularly essential for practical utilization of kinetic analysis for process design and to assess the performance of composite product during service life. This work aims to explore the impact of ILs assisted pretreatment of oil palm biomass on the thermal degradation kinetics of their fabricated biocomposites with thermoplastic starch as polymer matrix. The approach combines the pretreatment of oil palm frond (OPF) fiber with ILs 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) and 1-ethyl-3-methylimidazolium diethylphosphate ([Emim][dep]) prior to fabricate thermo-molded composite panels. Flynn–Wall–Ozawa method based on the model-free isoconversional approach was chosen to predict the activation energy of the biocomposites. Further, the influence of ILs pretreatment on physico-chemical properties of the OPF fiber was assessed by lignocellulosic characterization and crystallinity measurement. The results indicated that composites prepared with ILs pretreated OPF fiber exhibited 10–125% higher activation energy as compared to untreated composite over a conversion range of α = 0.1–0.6. Characterization of the untreated and pretreated fibers by examining the lignocellulosic fraction and analyzing the degree of crystallinity evidenced that ILs pretreatment increased the cellulose contents by 1.5–1.8 folds and caused significant reduction in the crystallinity of the OPF fiber. The present findings plainly indicate the promising potential of ILs based pretreatment as a new and clean processing approach for manufacturing of engineered composite panels from agricultural waste.

Sophorolipids (SLs) are surface active compounds that have excellent surface-lowering properties. Typically, SLs are produced using different hydrophobic substrates, such as alkanes, vegetable oils, and industrial effluents. The properties of the SLs are highly dependent on the hydrophobic substrate used for their production. The aim of the present study is to investigate the properties of SLs produced using three new hydrophobic substrates: Tapis oil, Melita oil, and Ratawi oil. The structures of the SLs were determined by Fourier transform infrared spectroscopy. The SLs yields using Tapis, Melita, and Ratawi oil were 26, 21, and 19 g L −1 , respectively. The SLs produced using Tapis, Melita, and Ratawi oil reduced the surface tension of pure water to 36.38, 37.84, and 38.92 mN/m, respectively, corresponding to critical micelle concentrations (CMCs) of 54.39, 55.68, and 58.34 mg L −1 . These values are comparable with SLs produced using palm oil (surface tension 35.38 mN/m and CMC 48.76 mg L −1 ). The SLs produced using Tapis oil show a maximum emulsification activity of 71.2%. The produced SLs are active over the pH range 2–10 and for salinity up to 20% (w/v) NaCl. Thus, they show potential for various applications, including microbial enhanced oil recovery and oil spill remediation.

Consolidated composite adsorbents have gained much attention as next generation adsorbents in adsorption heat pump (AHP) applications due to some of their salient features such as improved uptake to volume ratio and high thermal conductivity. Synthetic polymers, which are generally used as binders for the composite adsorbents impose negative impact on adsorption capacity resulting from poor affinity for the refrigerant and pore blockage. To address these issues, a polymerized ionic liquid (IL) was explored as a potential binder in making consolidated activated carbon composite. Polymerized IL [VBTMA][Ala] (vinylbenzyltrimethyl ammonium alanate) was synthesized and characterized. The composite adsorbent was prepared with a mass ratio of 90% Maxsorb III and 10% of Poly IL [VBTMA][Ala]. It is observed that surface area and pore volume of new composite were increased to more than 11% and 18%, respectively, compared to polyvinyl alcohol (PVA) as a binder. Sorption tests for ethanol uptake were performed using thermogravimetric technique at 303.15 K, 323.15 K and 343.15 K with various evaporator pressures. For a typical operating condition of AHP system, composite using polymerized IL as binder showed 22% higher net ethanol uptake than the net uptake of parent material Maxsorb III whereas a remarkably high 85% increase in thermal conductivity was observed. Thus, polymerized IL could be considered as strong candidate for making consolidated composite adsorbents in AHP applications.

Optimised harvesting of rainwater has been a challenge as the reliability of this water supply depends on many factors i.e. rainfall amount, tank size, roof area and rainwater demand. Various studies have been done in this context considering water usages, rainfall & roof area; and different methods were proposed to maximise the water supply reliability for an optimum rainwater tank. Among the analysis methods, a daily water balance method is the most acceptable and reasonably accurate, although, general end-users hardly can interpret outcomes of these analyses. This paper presents relationships of expected water savings under different climatic conditions for specific tank sizes with two major contributing factors; demand and roof area for an Australian city, Sydney. Expected annual water savings were calculated for different combinations of tank size, roof area and demand using an earlier developed daily water balance model, eTank. For a given tank size expected water savings for different roof areas and demands are presented in the form of charts for a user-friendly presentation to the end-users. Also, produced charts for a particular climatic condition were converted to a generalized equation having independent variables of roof area, tank size and demand to facilitate quick calculations through apps or computer. For the validity check of the developed equations, results from the equations were compared with the eTank simulated results and it is found that the results from the generalized equations are very close to the eTank produced results. To present spatial variability, similar charts and equations were produced for four different regions of Sydney.

The pharmaceutical industry faces a challenge to find potential solvents for drug molecules that are sparingly soluble in water and conventional organic solvents. Recently, ionic liquids (ILs) have attracted great attention as pharmaceutical solvents owing to their unique physicochemical and biological properties. In this study, the solubility of the sparingly soluble drug molecule acyclovir (ACV) in a wide variety of ILs was investigated by conductor-like screening model for real solvents (COSMO-RS) calculations. The predicted solubilities were validated by experimental measurements, and good agreement was found between the predicted and experimental results. The solubility of ACV was greatly affected by the structure of ILs, particularly the anionic moiety. Among the various ILs tested, ACV showed excellent solubility in ammonium-based ILs with an acetate anion. In vitro cytotoxicity of ILs to the MCF-10 normal breast epithelial cell line and cancer cell lines (MDA MB 231 and MCF 7) was investigated. The ammonium-based ILs showed higher IC 50 values than the imidazolium-based ILs with the acetate anion. Biodegradability results showed that diethylammonium acetate, triethylammonium acetate, and choline acetate ILs have high levels of biodegradation under aerobic conditions and can be classified as readily biodegradable. These findings will be useful for the design of IL-based drug delivery carriers that can act as versatile and efficient drug delivery systems for sparingly soluble drug molecules.

Gold nanoparticles (AuNPs) are attracting the researchers due to their potential applications in catalysis, bio medical, electrolysis and many other fields. However, a simple, efficient, cost effective and eco-friendly approach is still challenging to synthesize stable AuNPs. Ionic liquid (ILs) assisted bio-synthesis process can be attractive choice to produce AuNPs with enhanced colloidal stability. The aim of the study is to synthesize IL mediated stable AuNPs using bio-compounds extracted from oil palm leaves (OPL). To accelerate this study, IL[C 2 mim][Br], (1-ethyl-3-methylimidazolium bromide) was utilized for extraction of flavonoids. Changes in total flavonoids contents (TFCs) were measured over time during synthesis reaction of AuNPs to investigate its role for reduction of Au + 3 . Results suggested a decrease of TFCs from 34.83 mg CE/g to 10.98 mg CE/g during synthesis reaction which endorsed the contribution of flavonoids to reduce gold ions. The surface chemistry of AuNPs was examined through X-ray photoelectron spectroscopy (XPS) analysis which revealed a strong interaction of ILs and other organic moieties at their interfaces. AuNPs were also characterized through Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and Energy dispersive spectroscopy (EDAX) techniques to study the bio-functional groups, crystalline nature and presence of other elements in the reaction mixture. Colloidal AuNPs examined for two months to observe the change in the surface plasmon resonance (SPR) peak intensities, particles' size and zeta potential value characterized through UV–vis spectrophotometer, Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis, respectively. During experimental period, SPR peaks of AuNPs remained firm to their mean position. Nevertheless, it was observed a minor difference in particles' size and zeta potential values which were changed from 13.30 nm and − 23.2 mV to 15.22 nm and − 20.9 mV respectively endorsing a stable and dispersed colloidal suspension. Based on the flavonoids, a reaction mechanism was proposed to understand the synthesis and stabilization processes of IL mediated AuNPs synthesis.

Ionic liquids (ILs) pretreatment has emerged as a promising technology toward environmentally benign conversion of lignocellulosic residues into high value cellulosic fiber as sustainable raw material for biocomposite fabrication. This study presents a comparison of ILs-assisted pretreatment of oil palm fronds (OPF) fiber with dilute acid, alkaline, and hot compressed water pretreatments on the mechanical and thermal properties of their fabricated thermo-molded biocomposites with thermoplastic starch as a biopolymer binder. A comparison of energy consumption for ILs pretreatment with other pretreatment methods was also performed and the comparative impact of ILs pretreatment on OPF fiber was investigated by lignocellulosic composition, crystallinity and thermal stability analysis for untreated and all pretreated fibers. Results indicate that ILs pretreatment is superior in terms of delignification of OPF and produces cellulose rich fiber (CRF) with 48–50% reduced crystallinity as compared to those of acidic, alkaline, and hot water pretreated fibers. However, the flexural strength of the IL [emim][dep] treated composite (13.8 MPa) was significantly improved over that of untreated composite with value of 5.3 MPa, but was slightly higher than acidic and hot water pretreatments which were 13.5 MPa and 10.8 MPa, respectively. ILs pretreatment consumed about 0.5–2.0 folds more energy per kg of OPF residue as compared to other methods. In the premises of the present findings, we believe that ILs-based pretreatment could be a new, clean and promising alternative processing approach for conversion of a wide variety of agro-based lignocellulosic waste materials into cellulose-rich fibers for manufacturing of engineered biocomposite panels.

Ionic liquids (ILs) technology has been emerged as most prominent approach for the CO2 capture, which is an important phenomena in oil & natural gas industry during the gas sweetening process. The remarkable performance of IL polymers for the CO2 capture provided new opportunities to upgrade this technology in recent years. Therefore, in the present study, we have prepared different IL polymers namely poly(1-vinylimidazole), poly(1-vinyl-3-ethylimidazolium bromide), poly(1-vinyl-3-ethylimidazolium bis(trifluoro methylsulfonyl))imide and zeolite incorporated poly(1-vinyl-3-ethylimidazolium bis(trifluoro methylsulfonyl)imide materials and evaluated their CO2 capture efficiency. The synthesized IL polymers were characterized by FT-IR, FE-SEM and EDX. The CO2 sorption experiments were conducted using gas sorption cell, and the results revealed that zeolite incorporated IL polymer has adsorbed highest amount of CO2 (1.58mol) and recorded the highest pressure drop over other IL polymers. © 2020 Author(s). One of the authors A. Vijaya Bhasker Reddy thankful to Centre of Research in Ionic Liquids (CORIL), Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia for providing post-doctoral fellowship.