Eutectic Research Articles

Development of hydrophobic eutectic solvents composed of DL-menthol and fatty acids/alcohols: Application in the extraction of capsaicinoids and carotenoids from Capsicum frutescens

The aim of this work was to evaluate the use of DL-menthol as a eutectic solvent (ES) forming component with fatty acids (C8 to C18 acids) and alcohols fatty (C8OH to C12OH) and to identify the differences arising from the chirality between the racemic (DL-menthol) and the pure isomer (L-menthol). Moreover, the extraction of metabolite compounds from Capsicum frutescens using dried and water-saturated solvent was also investigated. The results obtained from the solid–liquid phase equilibria (SLE) diagrams showed the same eutectic point (0.2 M fraction for menthol) for both isomers. However, in both diagrams (melting and crystallization temperature) the DL-menthol-based ES exhibited a different solids line than the pure isomer at different temperatures, probably due to the D-isomer in the racemic mixture. The water content for DL-menthol: acids or fatty alcohols was very low, showing a range of 404–1067 ppm for the dried ones. For those water-saturated, values between 17,316 and 29,181 ppm were observed. Thermo-physical properties can provide important insights into intermolecular interactions and the ES structure. The density and viscosity values for these hydrophobic solvents were lower than most hydrophilic analogue solvents. Finally, these hydrophobic ES were applied to the extraction of carotenoids and capsaicinoids. The extraction efficiency values for carotenoids were higher than those for capsaicin due to the higher hydrophobicity of this compound. Furthermore, higher extraction values were also observed for water-saturated ES.

Kinetic liquid metal synthesis of flexible 2D conductive oxides for multimodal wearable sensing

Transparent conducting oxides (TCOs) are crucial for high-performance displays, solar cells, and wearable sensors. However, their high process temperatures and brittle nature have hindered their use in flexible electronics. In this paper, we overturn these limitations by harnessing Cabrera-Mott oxidation to fabricate large-area, two-dimensional (2D) transparent electrodes via liquid metal printing. Our robotic, vacuum-free process deposits ultrathin (2–10 nm) indium tin oxide (ITO) with exceptional flexibility, transparency (>95%) and conductivity (>1300 S/cm) by utilizing hypoeutectic In-Sn alloys to print at <140 °C. Detailed characterization reveals the efficacy of Sn-doping and high crystallinity with large, platelike grains. The ultrathin nature enhances bending strain tolerance and scratch resistance, exceeding durability of PEDOT and offering low contact impedance to skin comparable to Ag/AgCl. We implement 2D ITO in synchronous, multimodal electrocardiography (ECG) and pulse plethysmography (PPG) measurements. This order-of-magnitude improvement to printed TCOs could enable wearable biometrics and display-integrated sensors.

CHARACTERIZATION SUBSOLIDUS SYSTEM STRUCTURE CaO - Al2O3 - CoO – NiO

The paper presents the results of calculations characterizing the elements of the subsolidus structure of the CaO– Al2O3 – CoO – NiO system, which is promising for the production of modified aluminous cements and heterophase materials with a complex of unique properties. Insufficient information about the structure of the four-component phase diagram of a certain multicomponent system makes it difficult to obtain such materials. To predict the phase composition of materials, theoretical studies of the structure of the system were carried out. An analysis of the features of the coexistence of heterophase combinations was carried out, taking into account geometric-topological and statistical characteristics. The technological risks of predicting the phase composition of materials that arise in certain concentration regions of the system under study are shown. Calculations were carried out over the entire temperature range, both up to the melting point of the ternary oxide compound Ca3CoAl4O10 at 1439 K, and in a higher temperature region. Using known methods, the characteristics of eutectics in some sections of the system under study, which is of interest for the technological design of materials, were calculated. The results of calculations of the characteristics of eutectics show that among the analyzed tetrahedra, the minimum eutectic temperature (1367 K) is observed between the oxides of cobalt, nickel, calcium-cobalt aluminate and calcium monoaluminate, which can be realized for the synthesis of heterophase materials with a high content of Ca3CoAl4O10. Such materials have practical application in various industries: lime production; lime binders; corundum abrasives and refractories; high temperature catalysts; ceramics with special electromagnetic properties.

A Green Chemistry Approach to Catalytic Synthesis of Ethyl Levulinate

Esterification of levulinic acid with ethanol was investigated using deep eutectic systems based on choline chloride and oxalic or p-toluenesulfonic acid as catalysts under conventional heating and alternative energy inputs, namely microwave, ultrasound, and mechanochemical treatment. The experiments were performed under varying operating conditions such as catalyst type and loading, alcohol to carboxylic acid molar ratio, temperature, or time. The obtained results demonstrate the overall better catalytic performance of the p-toluenesulfonic acid-based deep eutectic mixture in comparison with the oxalic acid-based analogue. The best results: levulinic acid conversion of 76% and 58%, for p-toluenesulfonic and oxalic acid containing deep eutectic systems, respectively, with 100% selectivity for both cases, were achieved for microwave-assisted synthesis with 5 wt.% of catalyst and excess alcohol to acid (molar ratio 5), at 413.15 K and for 10 min. The main advantage of all of the alternative activation methods studied (microwaves, ultrasounds, and ball mill processing) was the significant reduction in the reaction time.

An Overview of Sustainable Desalination with Freezing Crystallization: Current Development, Future Challenges, and Prospects

As global demand for freshwater grows, seawater desalination has become one of the most promising methods for obtaining freshwater. Many coastal nations have included it in their sustainable development plans and are actively advancing related technologies. Compared with traditional desalination methods, such as distillation and membrane-based desalination, seawater freezing desalination offers the benefit of producing large amounts of freshwater at lower costs. This study provides an overview of the main methods and principles of seawater freezing desalination and summarizes the latest research progress. This paper also discusses experimental and simulation studies of different principles. Current research shows that both direct and indirect seawater freezing desalination technologies have become relatively mature, laying a foundation for practical applications. Hydrate-based desalination, eutectic freezing technology, and vacuum freezing technology offer cost-reduction benefits, but existing technologies have limitations, making these areas hot topics in research. Additionally, this paper discusses the experimental progress and simulation methods associated with this, elaborates upon, and analyzes the freezing crystallization process and desalination efficiency from the perspective of the bottom layer of crystal growth, offering valuable insights for future research. It concludes by summarizing and predicting the development of these technologies, emphasizing their great potential due to their low-cost and sustainable features.

Probing the potential of type V Deep eutectic solvents as sustainable electrolytes

The increasing interest within the scientific community in environmentally friendly solvents has led to a focus on Deep Eutectic Solvents (DES), which have natural components. DES are viewed as alternatives to traditional organic solvents and have the potential to be used as electrolytes. For the first time, transport properties of four Type V Deep Eutectic Salt Solutions (DESS) were accessed to investigate the potential of this technology, selecting precursors ranked as excellent in Eco-Scale metrics. The DESS were composed of terpene and trioctylphosphine oxide (TOPO), and varying concentrations of lithium bis(trifluoromethane)sulfonimide (LiTFSI), and their properties were assessed through self-diffusion, viscosity, density, and conductivity measurements. While Type V DESS are capable of dissolving significant amounts of LiTFSI (up to 30 % molar), their ionic conductivity is low, with values ranging from 3.6·10−3 to 9.3·10−2 mS·cm−1 at 25 °C, thus limiting their suitability as electrolytes, for instance, for lithium-ions batteries applications. Similar diffusion coefficients for Li+ and TFSI− ions suggest the formation of long-lived ion pairs moving as a neutral species. Therefore, future research aims to introduce additives to disrupt contact ion pairs and enhance transport properties, leveraging the sustainable appeal of DES and their use in advanced energy storage technologies.

Quantum chemical investigations into the structural and spectroscopic properties of choline chloride-based deep eutectic solvents

The chemical process industries are progressively embracing green technologies and sustainable waste management techniques due to growing environmental concerns and the impact of climate change. Deep eutectic solvents (DESs), formed by combining neutral molecules (e.g., choline chloride, ChCl) with hydrogen bond donors, have emerged as promising eco-friendly solvents with diverse applications in chemical, pharmaceutical, and separation processes. In this context, modern quantum-based research is focused on eutectic mixtures, particularly those formed by ChCl as a hydrogen bond acceptor with various hydrogen bond donors at specific mole ratios. The properties and validity of these DESs are investigated through density functional theory (DFT) analysis of their molecular dynamics simulations. This quantum computational approach offers valuable insights for designing the desired conductive liquids. Furthermore, the density of states analysis allows for studying the electronic structure and quantifying the number of states occupied per unit of energy. The quantum and vibrational properties of experimentally synthesized DESs are simulated using DFT B3LYP/6–31G(d,p). Current research aims to design and understand the properties of eutectic solvents to develop novel, environmentally benign alternatives for the chemical industry.

Unravelling the influence of water: Investigating the physicochemical properties of deep eutectic solvents based on choline chloride and pyruvic acid/α-keto glutaric acid

In the vast and intricate world of solution chemistry, deep eutectic solvents (DESs) have established a unique standing due to the easy accessibility of their components, along with their non-hazardous nature, biodegradability, recyclability, and cost-effectiveness. The main objective of this study is to investigate the key physicochemical properties of DESs, particularly those composed of choline chloride (ChCl) and pyruvic acid (referred to as pyruline), as well as those formulated with α-keto glutaric acid (referred to as glutaline). The initial investigation encompasses a comprehensive analysis of the thermal stability of the proposed DESs at 1:1, 1:2, and 2:1 M ratio, which were systematically assessed using TGA and DSC. The findings indicated that all eutectic mixtures exhibit a glass transition phenomenon instead of conventional melting and undergo a two-stage decomposition process. Following the thermal analysis of the neat DESs, the other physicochemical properties, including density, ionic conductivity, and electrochemical stability, were exclusively evaluated for the aqueous pyruline (1:1) and aqueous glutaline (2:1) pseudo-binary mixtures. The density studies of both proposed DES/H2O pseudo-binary mixtures across the temperature range of 293.15–343.15 K show a decrease with increasing temperature, accompanied by a corresponding increase in the thermal expansion coefficients (αP). Furthermore, the nonideal behaviour of the aqueous DESs was investigated by calculating the excess molar volume (VE) derived from density values across various temperature range and differing H2O mole fractions. The obtained VE demonstrated an excellent correlation with the Redlich–Kister polynomial equation. Additionally, the temperature dependent ionic conductivity of DES/H2O pseudo-binary mixtures was studied over the temperature range of 298.15–333.15 K. The cyclic voltammetry analysis offers a comprehensive insight into the electrochemical stability of DESs. Ultimately, the examination of binding energy (BE) and frontier molecular orbitals (FMOs) through density functional theory (DFT) offers valuable insights into the intermolecular interactions, molecular structures, and stability of DES clusters at the molecular level.

Development and characterization of saturated fatty acids and biopolymer based novel multilayer encapsulated phase change materials system for buildings

Application of encapsulated phase change materials (PCM) is becoming an attractive passive measure to develop energy efficient buildings. In the present work, the eutectic mixture of two saturated fatty acids (lauric acid and palmitic acid in 80:20 ratio, HTPCM) was selected and encapsulated in a novel multilayer architecture to develop PCM beads. The bead architecture includes a PCM core enveloped by thermally conductive calcium alginate (Ca-Alg) biopolymer + multiwall carbon nanotubes intermediate shell to promote heat transfer from the core and the outer rugged coating of flyash + water-based polyurethane (PU) to improve mechanical integrity and interlocking with wet cement mortar matrix during mix preparation. The thermal characteristics of four pure PCM (capric acid, lauric acid, myristic acid, and stearic acid) and one eutectic mixture (HTPCM) were measured using differential scanning calorimetry (DSC) to select the suitable PCM as per prevailing local ambient temperature. As per scanning electron microscopy (SEM) results, the average core size is in the range of 1.5 – 2.0 mm and PCM is stored in the bead core as tiny globules separated by Ca-Alg membrane. Single bead compression test performed on multilayer PCM (m-PCM) bead show that the shell of the bead possesses sufficient mechanical strength. The Fourier transformed infrared spectroscopy (FTIR) analysis and thermogravimetric analysis (TGA) studies confirm that the HTPCM and coating materials are chemically / thermally stable through different steps of fabrication and heating / cooling thermal cycles. Finally, the filter paper leakage test showed that the multilayer bead shell can prevent the PCM leakage from the core during bead heating. The various test results reported herein corroborate that the proposed architecture provides good physical properties and mechanical strength to the encapsulated PCM beads.

Structural characterization and physicochemical properties of different hydrophilic natural deep eutectic solvents.

To overcome the toxic nature of organic solvents, scientific interest in the use of green solvents, particularly natural deep eutectic solvents (NADES), has increased over the past decade, leading to new applications in the food, nutraceutical, pharmaceutical, and cosmetic industries. Understanding the physicochemical properties and molecular interactions of NADES is essential for uncovering new potential applications in these fields. In this study, several lactic and citric acid-based NADES, as well as chloride choline- and urea-based NADES, were evaluated for their physicochemical properties, including density, pH, viscosity, conductivity, and refractive index. Additionally, nuclear magnetic resonance (NMR), and in particular nuclear Overhauser enhancement spectroscopy (NOESY), was employed to investigate the intermolecular interactions between the NADES components to confirm the formation of the eutectic mixture. The extraction efficiency of the confirmed NADES was tested for extracting polyphenols as a proof of concept to highlight their relationship with the measured properties. Lactic and choline chloride-based NADES provided the highest extraction yields. These results were also compared with the predicted extraction capabilities of each NADES provided by the COSMO-RS software.

Designing an all-laser processing and operating microheater conceptual device for medical applications

Obstructive sleep apnea (OSA) is a prevalent condition affecting a significant portion of the population, with a reported prevalence of 33% and 19% in males and females, respectively. OSA is associated with an increased risk of sudden death, with studies suggesting nearly double the risk compared to individuals without OSA. The condition is characterized by frequent sleep disruptions due to airway collapse, often at the level of the tongue or soft palate. Current treatment approaches primarily rely on radiofrequency (RF) ablation for tissue volume reduction. While effective, this technique can cause significant collateral damage and postoperative pain due to extensive burning of surrounding tissues. To avoid such drawbacks, in this work it is proposed and discussed the features of a possible conceptual all-laser-processing and operating device that can produce localized heat affected zones, with the possibility to monitor the local temperature during the procedure. The device is based on the eutectic composition of the system Al2O3-YAG, with double doping Nd3+ and Cr3+ crystalline fiber tip, which is prepared by the Laser-Heated Pedestal Growth technique on a sapphire single crystal fiber end. The results showed that the tip, although highly Nd3+-doped, follows the Jackson-Hunt relation for binary eutectic compounds. The lifetime of the luminescence produced by the Cr3+ doping, emitted by the eutectic tip, can act as a temperature sensor for the device in the range of 30 to 100 °C.

One-Pot, Solvent Free Synthesis of 2,5-Furandicarboxylic Acid from Deep Eutectic Mixtures of Sugars as Mediated by Bifunctional Catalyst.

Currently one-pot conversion of sugars to 2,5-furandicarboxylic acid (FDCA) is of significant interest due to the attainability of sugars as a feedstock and the enormous potential of FDCA as a bioplastic monomer. However, it remains challenging to construct efficient catalysts for this process. In this study, Co3O4 species were anchored to a sulfonated covalent organic framework thus affording a bifunctional catalyst (Co3O4@COF-SO3H). The sulfonic acid sites dehydrate sugars to 5-hydroxymethylfurfural (HMF), which is next oxidized to FDCA as catalyzed by the Co3O4 species. Such a process was applied in the conversion of various binary and ternary deep eutectic mixtures involving choline chloride and sugars without additional solvent. The maximum FDCA yield of 84 % was obtained using glucose-fructose eutectic mixture as the substrates. Moreover, the catalyst was recyclable and stable under the applied reaction conditions. Our process eliminates the employment of organic solvents and expensive noble metal catalysts, resulting in green and economic biomass conversions.

Coexistence of Superconductivity and Magnetic Ordering in the In-Ag Alloy Under Nanoconfinement.

The impact of the interface phenomena on the properties of nanostructured materials is the focus of modern physics. We studied the magnetic properties of the nanostructured In-Ag alloy confined within a porous glass. The alloy composition was close to the eutectic point in the indium-rich range of the phase diagram. Temperature dependences of DC magnetization evidenced two superconducting transitions at 4.05 and 3.38 K. The magnetization isotherms demonstrated the superposition of two hysteresis loops with low and high critical fields below the second transition, a single hysteresis between the transitions and ferromagnetism with weak remanence in the normal state of the alloy. The shape of the loop seen below the second transition, which closes at a low magnetic field, corresponded to the intermediate state of the type-I superconductor. It was ascribed to strongly linked indium segregates. The loop observed below the first transition is referred to as type-II superconductivity. The secondary and tertiary magnetization branches measured at decreasing and increasing fields were shifted relative to each other, revealing the proximity of superconducting and ferromagnetic phases at the nanometer scale. This phenomenon was observed for the first time in the alloy, whose components were not magnetic in bulk. The sign of the shift shows the dominant role of the stray fields of ferromagnetic regions. Ferromagnetism was suggested to emerge at the interface between the In and AgIn2 segregates.

GPa level pressures on the microstructure evolution of eutectic high-entropy alloys CoCrFeNi(TiNb)0.325 and corrosion resistance

In this study, high-pressure solidification (HPS) was used to systematically investigate the microstructure evolution and corrosion resistance of the designed eutectic high-entropy alloy CoCrFeNi(TiNb)0.325 under ambient pressure, 4 GPa and 7 GPa. With increasing solidification pressure, the eutectic component points continue to move toward the upper left of the phase diagram, and the microstructure of the EHEA changes from eutectic under AP to hypereutectic at 4 GPa. Finally, the eutectic lamellar structure disappears under 7 GPa pressure, and the microstructure shows a divorced eutectic morphology. Mott–Schottky and XPS analyses revealed that the passivation film defect density of the HPS sample was lower than that of the other samples, but because the increase in the FCC/Laves phase spacing promoted pitting nucleation, the sample was difficult to repassivate, thus weakening the pitting corrosion resistance of the HPS sample. This work provides new insights into the relationships among pressure, microstructure, and corrosion performance.

Eutectic binary phase diagram and kinetically stable homogeneous co-amorphous mixtures of two imidazole drugs

Amorphous multicomponent formulations allow improving the solubility and thus the bioavailability of active pharmaceutical ingredients (APIs) that are poorly soluble in water, provided that the molecular mobility in such formulations does not promote crystallization in the amorphous (glassy) state during their shelf life. Multicomponent formulations may involve a single API mixed with excipients, but also two mutually compatible APIs. Here, we describe kinetically stable amorphous binary mixtures of two commercial antifungal imidazole APIs, bifonazole and clotrimazole, which have similar melting points and glass transition temperatures. The equilibrium phase diagram of this binary system, as determined by differential scanning calorimetry, follows the Schroeder-van Laar-LeChatelier predictions, as typically found for compounds that are miscible as liquids but immiscible in the crystalline form, and is characterized by an experimental eutectic composition close to equimolar composition (xbifonazole = 0.45) and eutectic melting point Te = 392 K. The glass transition temperature Tg varies linearly with composition, as found in ideal liquid mixtures. Dielectric spectroscopy characterization is carried out to investigate the relaxation dynamics of each amorphous API separately, and of the amorphous mixtures (both in the supercooled liquid and glass state). A single structural α relaxation is observed in all supercooled liquid mixtures, confirming their homogeneity. Both pure amorphous APIs display conformational secondary relaxations: the one of bifonazole stems from the torsional rotation of the imidazole ring; the one of clotrimazole is significantly slower than that of bifonazole, and is related to small-angle librations of the imidazole and chlorobenzene rings. Conformational relaxation processes are observed also in binary mixtures, which display also a Johari-Goldstein relaxation as pure clotrimazole. Despite the presence of both primary and secondary relaxations, the binary mixtures are observed to remain amorphous for at least twelve months both at Tg and slightly above it.

The preparation and properties of bamboo lignocellulosic nanofibers based on deep eutectic solvent system

The preparation and properties of bamboo lignocellulosic nanofibers based on deep eutectic solvent system

Exploring the dynamic world of ternary deep eutectic solvents: Synthesis, characterization, and key properties unveiled

Deep eutectic solvents are a novel class of solvents that have gained much attention with time due to their biodegradability, non-volatility, non-toxicity and low-cost. In this work, a novel ternary deep eutectic solvent (TDES) was synthesized using ethaline (ChCl:EG) and glycine, with the addition of carboxylic acids. The synthesized material was characterized through Fourier-transform infrared spectroscopy (FTIR). While the thermal stability and physical properties such as density, viscosity, surface tension and refractive index were also determined). To estimate the critical properties, modified version of Lyderson-Joback-Reid (LJR) and Lee-Kesler mixing (Alkhatib et al., 2020) [1] methods were used. The density of the DES was calculated using the Spencer and Danner correlation and the obtained values were compared with experimental data. FTIR analysis confirmed that hydrogen bonding is the main driving force responsible for the formation of the deep eutectic solvents. The physical properties of the binary DES system, such as viscosity, density,and thermal stability of the system were enhanced after the incorporation of a third component (carboxylic acid) to the system. However, the surface tension of the TDES system decrease with the increasing amounts of the third component, likely due to increase in the void radius of the TDES. Thus investigation is considering as novel work to check the influence of carboxylic acids on the physical properties of binary deep eutectic solvent systems.

In-situ synthesis and microstructural evolution of a SiC reinforced Al-50Si composite exhibiting exceptional thermal properties

Incorporating carbon nanotubes (CNTs) into Al-Si alloy to prepare in-situ SiC/Al-Si composites enhances thermal conductivity (TC) and reduces the coefficient of thermal expansion (CTE). However, challenges include CNTs aggregation and uneven SiC distribution. This study uses fluidized bed chemical vapor deposition (FBCVD) to achieve uniform CNTs coverage on Al-50Si powder. Subsequent powder hot extrusion and heat treatment above the eutectic temperature enable a gradual reaction between CNTs and Al/Si atoms, resulting in uniformly dispersed SiC within the SiC/Al-50Si composite. The formation mechanism of in-situ SiC particles and their impact on the microstructure, thermal and mechanical properties of the composite are further investigated. The formation process involves a two-step chemical reaction: lamellar Al4C3 phases transform into lamellar eutectic SiC + Al phases, which then transition into polyhedral SiC particles through epitaxial growth. This in-situ formation of SiC particles also impedes Si growth during heat treatment, refining Si particles and enhancing the composite’s properties. The resulting in-situ SiC/Al-50Si composite exhibits excellent thermal and mechanical properties, including a high TC of ∼162 Wm-1K−1, a low CTE of ∼ 8.7 × 10-6/K, and a good bending strength of approximately 253 MPa at room temperature.

Enhancing CO2 solubility for efficient carbon capture via self-assembly deep eutectic solvents on MOF-808

The capture of CO2 from flue gas has emerged as the most effective technology for carbon reduction. The relatively low partial pressure of CO2 in flue gas necessitates the development of CO2-selective adsorbents, which provide a direct pathway to obtaining pure CO2 in one-step, thereby reducing energy consumption. Herein, an amino-rich deep eutectic solution (DES) is dispersed on the surface of formate ligand-removed MOF-808 using a self-assembly approach for post-combustion carbon capture. The high solubility of DES towards CO2 enables the composite to effectively capture CO2, with MOF-808 serving as a porous gas storage tank. Material characterization confirms the loading of DES on the surface of MOF support while retaining its microporous structure. Owing to their unique CO2 solution-diffusion mechanism, DES-modified adsorbents exhibit promising performance on CO2 capacity, kinetics, CO2/N2 selectivity, and isosteric heat. The optimized sample DES-2@MOF-808-FR demonstrates a notable CO2 adsorption capacity of 4.16 mmol/g at 298 K and 1 bar. When tested with simulated flue gas (15 vol% CO2), it maintains a working capacity of 2.86 mmol/g and a CO2/N2 selectivity of 1184, surpassing most of existed materials. DES-2@MOF-808-FR can also retain its capacities after 10 adsorption/desorption cycles in simulated flue gas. This solution-based modification approach circumvents the challenges associated with precise structural control of the adsorbent, thereby facilitating potential industrial applications.

The Impact of Selected Eutectic Solvents on the Volatile Composition of Citrus lemon Essential Oil.

The development of new materials for the controlled release of molecules represents a topic of primary importance in medicine, as well as in food science. In recent years, eutectic solvents have been applied as releasing media due to their improved capacity to interact with specific molecules, offering a broad range of tunability. Nevertheless, their application in essential oil dissolution are rare and more data are needed to develop new generations of effective systems. Herein, three eutectic systems, respectively, composed of choline chloride and ethylene glycol (1:2 molar ratio), methyltriphenylphosphonium bromide and ethylene glycol (molar ratio 1:5), and choline chloride and glycerol (molar ratio 1:1.5) were tested as materials for the controlled release of an essential oil derived from Citrus lemon leaves. Through static headspace fractionation, followed by gas chromatographic analysis, the performances of the three systems were assessed. The specific composition of DESs was pivotal in determining the releasing polar molecules as aldehydes and alcohols. A sustainability ranking based on the EcoScale tool highlighted the superior characteristics of the choline chloride-glycerol DES.