Short alkyl-chained Imidazolium-based Ionic Liquids: Promising green solution or potential environmental threat?

Ionic Liquids (ILs) are currently applied in a wide variety of fields, with promising outcomes in microalgae high value biocompounds extraction. The occurrence of these compounds in natural water systems, with their characteristic stability and low biodegradability, becomes a threat worthy of attention. In the present study, Dunaliella tertiolecta, Isochrysis galbana and Rhinomonas reticulata were exposed to 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM] TfN) for 72, 168 and 264 h, at 20 and 25 °C.

Subcellular effects of imidazolium-based ionic liquids with varying anions on the marine bivalve .

Green Chemistry involves applying a set of principles aimed at minimizing the use of hazardous substances in the design, production, and application of chemical products. In recent decades, Ionic Liquids (ILs) have emerged as more environmentally friendly substitutes for traditional organic solvents. This preference is primarily due to their low vapor pressure, which results in minimal atmospheric pollution and enhanced industrial safety.

A Combined Experimental/Computational Study of Dicationic Ionic Liquids with Bromide and Tungstate Anions.

A panel of dicationic ionic liquids (DILs) with different rigid xylyl (ortho, meta, para) spacers and different anions (bromide and tungstate) has been synthetised and characterised through different experimental and computational techniques. Differences and analogies between the systems are analysed using information derived from their DFT structures, semiempirical dynamics, thermal behaviour, and catalytic properties versus the well-known reaction of CO added to epichlorohydrin. A comparison between the proposed systems and some analogues that present non-rigid spacers shows the key effect displayed by structure rigidity on their characteristics.

A thiol-ene mediated approach for peptide bioconjugation using 'green' solvents under continuous flow.

Flow chemistry has emerged as an integral process within the chemical sector permitting energy efficient synthetic scale-up while improving safety and minimising solvent usage. Herein, we report the first applications of the photoactivated, radical-mediated thiol-ene reaction for peptide bioconjugation under continuous flow. Bioconjugation reactions employing deep eutectic solvents, bio-based solvents and fully aqueous systems are reported here for a range of biologically relevant peptide substrates.

Structure-Dependence and Mechanistic Insights into the Piezoelectric Effect in Ionic Liquids.

We reported recently that two imidazolium room-temperature ionic liquids (RTILs) exhibit the direct piezoelectric effect (, , 14, 2731-2735). We have subsequently investigated several other RTILs with pyrrolidinium and imidazolium cations and tetrafluoroborate and bis(trifluoromethylsulfonyl)imide anions in an effort to gain insight into the generality and mechanism of the effect. All the RTILs studied exhibit the direct piezoelectric effect, with a magnitude () and threshold force that depend on the structures of both the cation and anion.

Betaine mediated enhancement of thermal stability and acidity tolerance of vanadium(V) solutions.

A panel of novel vanadium(IV)-betaine complexes has been synthesized according to new and efficient methodologies and characterized through both spectroscopic techniques and thermal analyses. Vanadium(IV)-betaine solutions have been electrochemically oxidized and the effect of betaine ligands on the thermal and pH stability of vanadium(V) solutions has been evaluated under different temperature and acidity conditions. The obtained results displayed a remarkable effect for both of the examined parameters, achieving the preparation of aqueous vanadium(V) solutions displaying long term stability at more than 55 °C under mild acidic conditions.

Challenging DESs and ILs in the valorization of food waste: a case study.

In this study, the efficacy of two of the best performing green solvents for the fractionation of lignocellulosic biomass, cholinium arginate (ChArg) as biobased ionic liquid (Bio-IL) and ChCl:lactic acid (ChCl:LA, 1:10) as natural deep eutectic solvent (NADES), was investigated and compared in the pretreatment of an agri-food industry waste, apple fibers (90°C for 1 h). For the sake of comparison, 1-butyl-3-methylimidazolium acetate (BMIM OAc) as one of the best IL able to dissolve cellulose was also used. After the pretreatment, two fractions were obtained in each case.

In vitro screening of imidazolium and pyrrolidinium based ionic liquids toxicity on subcellular fractions of the Mediterranean mussel Mytilus galloprovincialis.

Ionic liquids (ILs) have been considered eco-friendly alternatives to conventional organic solvents. However, several studies have reported that ILs exert toxicity towards aquatic invertebrates. Applying in vitro methodology, the aim of the present study was to evaluate the potential effect of three ILs on the biochemical performance of exposed Mytilus galloprovincialis digestive gland and gills cellular fractions.

Fibrinogen-Based Bioink for Application in Skin Equivalent 3D Bioprinting.

Three-dimensional bioprinting has emerged as an attractive technology due to its ability to mimic native tissue architecture using different cell types and biomaterials. Nowadays, cell-laden bioink development or skin tissue equivalents are still at an early stage. The aim of the study is to propose a bioink to be used in skin bioprinting based on a blend of fibrinogen and alginate to form a hydrogel by enzymatic polymerization with thrombin and by ionic crosslinking with divalent calcium ions.

Lignin-Derivative Ionic Liquids as Corrosion Inhibitors.

Corrosion is a significant problem that negatively affects a wide range of structures and buildings, resulting in their premature failure, which causes safety hazards and significant economic loss. For this reason, various approaches have been developed to prevent or minimize the effects of corrosion, including corrosion inhibitors. Recently, biobased inhibitors have gained a certain interest thanks to their unique properties, eco-friendliness, and availability.

Marine Collagen-Based Bioink for 3D Bioprinting of a Bilayered Skin Model.

Marine organisms (i.e., fish, jellyfish, sponges or seaweeds) represent an abundant and eco-friendly source of collagen.

Betaine- and L-Carnitine-Based Ionic Liquids as Solubilising and Stabilising Agents for the Formulation of Antimicrobial Eye Drops Containing Diacerein.

The therapeutic efficacy of topically administered drugs, however powerful, is largely affected by their bioavailability and, thus, ultimately, on their aqueous solubility and stability. The aim of this study was to evaluate the use of ionic liquids (ILs) as functional excipients to solubilise, stabilise, and prolong the ocular residence time of diacerein (DIA) in eye drop formulations. DIA is a poorly soluble and unstable anthraquinone prodrug, rapidly hydrolysed to rhein (Rhe), for the treatment of osteoarthritis.

Toxicity of ionic liquids in marine and freshwater microorganisms and invertebrates: state of the art.

The variety of applications and expected growth in ionic liquid production are raising concerns about the release of these compounds into aquatic systems. Up to date, 103 studies have provided ecotoxicological data regarding the exposure effects of Ionic Liquids towards aquatic microorganisms and invertebrate species: 61 were devoted to freshwater species (n = 28), while marine species (n = 12) were mentioned in 42. The aim of this review, by gathering published studies on ionic liquids and model aquatic organisms, was to present the toxic effects described in distinct species and to understand which are the main factors influencing the toxicity of some ionic liquids.

The Structure-Property Relationship of Pyrrolidinium and Piperidinium-Based Bromide Organic Materials.

Two couples of dicationic ionic liquids, featuring pyrrolidinium and piperidinium cations and different linker chains, were prepared and characterized. 1,1'-(propane-1,3-diyl)bis(1-methylpyrrolidinium) bromide, 1,1'-(octane-1,8-diyl)bis(1-methylpyrrolidinium) bromide, 1,1'-(propane-1,3-diyl)bis(1-methylpiperidinium) bromide, and 1,1'-(octane-1,8-diyl)bis(1-methylpiperidinium) bromide were synthesized in quantitative yields and high purity and thermally characterized through TGA and DSC analysis. In this study, we propose a preliminary comparative evaluation of the effect of the linker chain length and of the size of the aliphatic ammonium ring on the thermal and solubility properties of bromide dicationic ionic liquids.

A Specific Interaction between Ionic Liquids' Cations and Reichardt's Dye.

Solvatochromic probes are often used to understand solvation environments at the molecular scale. In the case of ionic liquids constituted by an anion and a cation, which are designed and paired in order to obtain a low melting point and other desirable physicochemical properties, these two indivisible components can interact in a very different way with the probe. This is the case with one of the most common probes: Reichardt's Dye.

Sporopollenin Microcapsule: Sunscreen Delivery System with Photoprotective Properties.

In recent years, the demand for high-quality solar products that combine high efficacy with environmentally friendly characteristics has increased. Among the coral-safe sunscreens, ethylhexyl triazone (Uvinul T150) is an effective organic UVB filter, photostable and practically insoluble in water, therefore difficult to be formulated in water-based products. Oil-free sunscreens are considered ideal for most skin types, as they are not comedogenic and do not leave the skin feeling greasy.

Are natural deep eutectic solvents always a sustainable option? A bioassay-based study.

The traditional use of organic solvents in various branches of industry is being rethought as these compounds very often display high volatility, toxicity and lipophilicity (related to the ability to interact with biological membranes). More recently, developments in the field of Green Chemistry are focusing on the design of more sustainable and cost-effective solvent alternatives like Ionic Liquids (ILs), bio-based solvents and natural deep eutectic solvents (NADESs). The present study aimed at performing an ecotoxicological screening of 15 NADESs using an extensive set of marine and freshwater bioassays, based on different endpoints as the following: immobilization of the crustacean Daphnia magna, growth inhibition of Raphidocelis subcapitata and of Phaeodactylum tricornutum, larval development alterations on the serpulid Ficopomatus enigmaticus and bioluminescence inhibition of Aliivibrio fischeri.

Purple non-sulfur bacteria as cell factories to produce a copolymer as PHBV under light/dark cycle in a 4-L photobioreactor.

The present study reports a strategy to produce polyhydroxyalkanoates (PHAs) by culturing the marine bacterium Rhodovulum sulfidophilum DSM-1374. The study was carried out by growing the bacterium anaerobically for 720 h under 16/8 light/dark cycle. Two analytical techniques such as proton magnetic nuclear magnetic resonance (H NMR) and Fourier transform infrared spectroscopy (FT-IR) were used to determine that the polyester produced was poly-3-hydroxybutirate-co-3-hydroxyvalerate (PHBV).

Dielectric Study of Tetraalkylammonium and Tetraalkylphosphonium Levulinate Ionic Liquids.

Broadband dielectric spectroscopy in a broad temperature range was employed to study ionic conductivity and dynamics in tetraalkylammonium- and tetraalkylphosphonium-based ionic liquids (ILs) having levulinate as a common anion. Combining data for ionic conductivity with data obtained for viscosity in a Walden plot, we show that ionic conductivity is controlled by viscosity while a strong association of ions takes place. Higher values for ionic conductivities in a broad temperature range were found for the tetraalkylphosphonium-based IL compared to its ammonium homolog in accordance with its lower viscosity.

Combination of Two Kinds of Medicated Microparticles Based on Hyaluronic Acid or Chitosan for a Wound Healing Spray Patch.

Olive leaves extract (OLE) has been extensively studied as antioxidant and antibiotic and these characteristics make it particularly interesting for use on wounds. For this reason, the aim of this study was to introduce OLE in microparticles (MP) of hyaluronic acid (MPHA-OLE) or chitosan (MPCs-OLE) to obtain a spray patch for the treatment of wounds in anatomical areas that are difficult to protect with traditional patches. The MP were characterized for particle size and ability to protect OLE from degradation, to absorb water from wound exudate, to control OLE release from MP.

Extraction of Polyhydroxyalkanoates from Purple Non-Sulfur Bacteria by Non-Chlorinated Solvents.

In this study, non-chlorinated solvents such as cyclohexanone (CYC) and three ionic liquids, (ILs) (1-ethyl-3-methylimidazolium dimethylphosphate, [EMIM][DMP], 1-ethyl-3-methylimidazolium diethylphosphate, [EMIM][DEP] and 1-ethyl-3-methylimidazolium methylphosphite, [EMIM][MP]) were tested to extract polyhydroxyalkanoates (PHAs) from the purple non-sulfur photosynthetic bacterium (PNSB) DSM-1374. The photosynthetic bacterium was cultured in a new generation photobioreactor with 4 L of working volume using a lactate-rich medium. The extracted PHAs were characterized using a thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, proton nuclear magnetic resonance and gel permeation chromatography.

Influence of the Use of an Ionic Liquid as Pre-Hydrodistillation Maceration Medium on the Composition and Yield of L. Essential Oil.

L. is a multi-purpose crop, whose resilience, adaptability and soil-enriching properties make it a low-impact production. In the last years, the cultivation of the "industrial" hemp varieties (THC < 0.

Expanding the Chemical Space of Benzimidazole Dicationic Ionic Liquids.

Benzimidazole dicationic ionic liquids (BDILs) have not yet been widely explored in spite of their potential. Therefore, two structurally related families of BDILs, paired with either bromide or bistriflimide anions and bearing alkyl spacers ranging from C3 to C6, have been prepared. Their thermal properties have been studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), while their electrical properties have been assessed by cyclic voltammetry (CV).

pH-Responsive Nanostructures Based on Surface Active Fatty Acid-Protic Ionic Liquids for Imiquimod Delivery in Skin Cancer Topical Therapy.

For topical treatment of skin cancer, the design of pH-responsive nanocarriers able to selectively release the drug in the tumor acidic microenvironment represents a reliable option for targeted delivery. In this context, a series of newly synthesized surface-active fatty acid-protic ionic liquids (FA-PILs), based on tetramethylguanidinium cation and different natural hydrophobic fatty acid carboxylates, have been investigated with the aim of developing a pH-sensitive nanostructured drug delivery system for cutaneous administration in the skin cancer therapy. The capability of FA-PILs to arrange in micelles when combined with each other and with the non-ionic surfactant d-α-Tocopherol polyethylene glycol succinate (vitamin E TPGS) as well as their ability to solubilize imiquimod, an immuno-stimulant drug used for the treatment of skin cancerous lesions, have been demonstrated.