Search

Orange and coffee grounds by-products, rich in phenolic bioactive compounds, can be used in the food industry as antioxidants, colorants, flavorings and additives, mainly because they are solvents that are easy to prepare, have a lower cost, are thermally stable, biodegradable, renewable, and are considered GRAS (Generally Recognized as Safe). Deep eutectic solvents, which are sustainable and have lower melting points, are effective for extracting these compounds. This study aimed to evaluate the use of deep eutectic solvents (DES) in extracting Total Phenolic Compounds (TPC), from orange by-products and spent coffee grounds. DES formed by citric acid: mannitol (CM-DES), and lactic acid: glucose (LG-DES), were evaluated by varying the following parameters: water content (10–50%), solid–liquid ratio (1:5–1:50 w/w) and temperature (40–50 °C). DES citric acid: mannitol presented the best efficiency in the extraction of TPC under the conditions of 10% water, 80 °C, and solid–liquid ratio 1:10 (w/w) for the orange by-products (1782.92 ± 4.50 mg GAE/L) and 1:15 (w/w) for spent coffee grounds (1620.71 ± 3.72 mg GAE/L). The highest antioxidant activity was observed in the extraction with CM-DES for both by-products in the three methods evaluated: Ferric Reducing Antioxidant Power (FRAP) (1.087 ± 0.004 and 1.071 ± 0.006 mol ascorbic acid/L), DPPH radical scavenging activity (2,2-difenil-1-picrilhidrazil—DPPH) (0.233 ± 0.003 and 0.234 ± 0.001 mol Trolox equivalent/L), and radical cation scavenging activity ABTS (2,2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid—ABTS) (0.284 ± 7.16 and 0.319 ± 0.002 mol Trolox equivalent/L). Therefore, DES with citric acid: mannitol is a promising alternative to conventional solvents to recover phenolic compounds in agro-industrial by-products, such as orange by-products and SCG. [ABSTRACT FROM AUTHOR]

This study successfully synthesized urea-1.3AlCl3 deep eutectic solvent by mixing and stirring urea and aluminum chloride in an inert gas-filled glove box at 25 ℃. By adding different concentrations of AlF3, it was found that the viscosity of the urea-1.3AlCl3 deep eutectic solvent continuously increased, resulting in the lowest resistance of 187.06 Ω and conductivity of 2.197 mS/cm. Additionally, this study used the obtained deep eutectic solvent (urea-1.3AlCl3 with AlF3) as a non-aqueous electrolyte for aluminum-air batteries and investigated its electrochemical and discharge characteristics. The data showed an improvement in output power. Comparing the discharge performance of different concentration electrolytes at a temperature of 323.15 K, it was found that the electrolyte containing 0.3 mol/L AlF3/urea-1.3AlCl3 had the highest discharge voltage of 1.29. [ABSTRACT FROM AUTHOR]

The rising global population has led to an escalating demand for affordable, high-quality proteins intended for human consumption. Different efforts have been made to develop efficient and greener solvents for protein production. Most proteins are produced from raw plant and animal parts, but the use of the residues in commercial-scale protein production is very scarce. Therefore, this research aims to collect an overview of deep eutectic solvents (DESs) and natural deep eutectic solvents (NADESs) for protein extraction and purification. In this context, solvent type and operating parameters should also be selected to modify DESs and NADESs physicochemical characteristics for the achievement of high protein yield with preserved functional properties. The results show that appropriate implementation of combined DESs and NADESs with advanced extraction and purification techniques can improve protein yield and prevent detrimental effects on the extracted protein and environment. The application of DESs and NADESs can increase the efficiency of protein extraction and recovery in various parts of plants and animals by 55.72% and 98.16%, respectively, with purity reaching 99.82%. This research also reviews safety, environmental impacts, and drawbacks as well as shows feasible future recommendations for commercial-scale protein production processes. NADESs are safer than petroleum-based solvents but have higher toxicity than DESs. Magnetic adsorbent and magnetic solid-phase extraction methods have been shown to reduce labor-intensive steps, resulting in shorter operating times and superior protein recovery while maintaining functional properties. Meanwhile, protein producers' knowledge and motivation to use DES and NADES are strengthened.

For wider use of starch in the production of biodegradable plastics, it is necessary to search for new effective plasticizers. In this study, the effect of seven deep eutectic solvents (DES) based on choline chloride and carboxylic acid (levulinic, lactic, malonic, itaconic, malic, tartaric and citric) on the properties of potato starch were investigated. For this purpose, the thermal and rheological properties of starch/DES mixtures were evaluated. The viscosity of aqueous starch/DES solutions was determined. Subsequently, the starch films were obtained by casting. To determine the plasticization efficiency, mechanical properties, crystallinity and moisture resistance were evaluated. The correlation between the properties of the starch films and the molecular structure of DES acidic component was revealed.

• An updated review on ROS implicated in AOPs for pharmaceutical waste is presented. • Potential ROS are implicated in the pharmaceutical waste degradation. • Mechanistic insights regarding ROS-mediated reaction pathways are discussed. • The main detected transformation products of ACT using specific ROS are reported. Innately designed to induce physiological changes, pharmaceuticals are foreknowingly hazardous to the ecosystem. Advanced oxidation processes (AOPs) are recognized as a set of contemporary and highly efficient methods being used as a contrivance for the removal of pharmaceutical residues. Since reactive oxygen species (ROS) are formed in these processes to interact and contribute directly toward the oxidation of target contaminant(s), a profound insight regarding the mechanisms of ROS leading to the degradation of pharmaceuticals is fundamentally significant. The conceptualization of some specific reaction mechanisms allows the design of an effective and safe degradation process that can empirically reduce the environmental impact of the micropollutants. This review mainly deliberates the mechanistic reaction pathways for ROS-mediated degradation of pharmaceuticals often leading to complete mineralization, with a focus on acetaminophen as a drug waste model. [ABSTRACT FROM AUTHOR]

In this study, a dispersive liquid–liquid microextraction along with a back-extraction step (DLLME-BE) has been developed for the determination of thre antidepressant drugs (citalopram, sertraline, and venlafaxine) in biological samples prior to HPLC-UV. Briefly, the method involved two main steps: first, a deep eutectic solvent (DES) composed of tetrabutylammonium bromide (TBABr as a dispersive agent) and 1-dodecanol (as the extraction solvent) was decomposed in an aqueous phase and led to in situ dispersion of the organic phase and extraction of analytes.. Second, Air-assisted liquid–liquid microextraction (AALLME) was applied to back-extract analytes into 50 µL of an aqueous acceptor phase while many interferences were not able to extract into the acceptor solution. By performing this developed extraction method, a high sample clean-up was achieved. The maximum efficiency of analytes was obtained based on the optimisation of the main parameters. Validation of the method indicated that the limits of detection (LODs) and limits of quantifications (LOQs) were in the range of 0.7–3.9 µg L−1 and 2.1–9.8 µg L−1 respectively. The extraction recoveries and enrichment factors of analytes were obtained to be in the range of 87.1–99.1% and 89–102, respectively. Finally, the method was utilised for extraction of three antidepressant drugs in water, human urine and plasma samples. [ABSTRACT FROM AUTHOR]

Graphene (GP), when used as a lubricant additive, not only reduces the friction coefficient but also enhances wear resistance by forming a protective lubrication film. However, there are still several challenges in practical applications related to graphene preparation. Therefore, this study employs a novel type of ionic liquid deep eutectic solvent as an interlayer agent for graphene preparation and investigates its tribological properties when used as an additive. We used choline chloride/ethylene glycol deep eutectic solvent as the intercalation agent and successfully prepared graphene samples using liquid-phase exfoliation. The resulting graphene samples had a thickness of 4–5 layers. The peeling mechanism is analyzed through molecular dynamics simulations and characterization techniques such as Raman spectroscopy, XRD, SEM, and AFM. In friction experiments conducted with different mass fractions of 1.5 wt% DES and 0.05 wt% GP as lubricant additives, it is observed that the mixture exhibits optimal lubrication performance compared to base oil alone; specifically reducing average friction coefficient by 56.8% and depth of wear marks by 59.8%. This enhancement in friction performance can be attributed to both high wettability and synergistic effects between composite lubricants. Considering the wide range of available DESs and two-dimensional materials, these newly developed functional two-dimensional materials based on DES hold significant research potential. [ABSTRACT FROM AUTHOR]

In this study, accurate and sensitive determination of ibuprofen in blood, urine, pharmaceutical tablet, syrup, and water samples was accomplished with the combination use of deep eutectic solvent-based ultrasound-assisted liquid–liquid microextraction (DES-UA-LLME) and high-performance liquid chromatography-ultraviolet visible detection system. The most important advantage of this method is that it can be used in the determination of ibuprofen without affecting the matrix environment of a wide range of samples. Ibuprofen in the sample phase was extracted to 500 µL of deep eutectic solvents phase (ChCl:Ph at 1:4 molar ratios) at pH 3.0. The influence of analytical parameters, such as pH of sample solution, the molar ratio of deep eutectic solvents components, tetrahydrofuran volume, and volume of DESs, were optimised in details. The preconcentration factor (PF), the detection limit (DL), intraday, and interday relative standard deviations (RSD, %) for the developed DES-UA-LLME/HPLC procedure were found as 30, 0.4 µg L−1, 1.74%, and 4.68%, respectively. The developed DES-UA-LLME was successfully used for the determination of ibuprofen in urine, blood, pharmaceutical tablet, syrup, and water samples. [ABSTRACT FROM AUTHOR]

For the rapid and efficient determination of acrylamide in food products by HPLC-UV, an environmentally friendly analytical approach has been developed, including liquid-phase extraction and subsequent liquid–liquid microextraction using a deep eutectic solvent. To automate the procedure, the flow-through "lab in a syringe" method was used. Acrylamide is considered a potential endocrine disrupting chemical and its main source is fried foods, which are widely consumed by both children and adults. To extract and concentrate acrylamide, hydrophobic deep-eutectic solvents based on various carboxylic acids and natural terpenoids were studied for the first time. It was found that benzoic acid, as a precursor of the extraction solvent, promotes the transfer of hydrophilic acrylamide from the aqueous phase of the sample due to the interaction of carboxyl and amide groups. The procedure has been validated and used effectively to estimate acrylamide content in beetroot and corn chips. Under optimal conditions, the detection limit was 0.01 mg/kg. Unlike existing methods, the proposed method is fully automated, does not require hazardous organic solvents and additional derivatization stages, and at the same time allows the determination of acrylamide at a level below established standards. [ABSTRACT FROM AUTHOR]

Abstract A leading cause of global warming is the increase of carbon dioxide (CO2) emissions due to anthropogenic activities which prompts an urgent need for substantial reduction. Recently, CO2 absorption in deep eutectic solvents (DESs) has attracted scientific attention, because of their adaptability compared to traditional ionic liquids and aqueous amine solutions. This study employs the heating method to synthesize DESs using tetrapropylammonium bromide (TPAB) and formic acid (Fa) with molar ratios of TPAB-Fa (1:1) and TPAB-Fa (1:2). Absorption experiments by static method quantified CO2 solubility in the DESs under varied pressures and temperatures. TPAB-Fa (1:2) at 25.0 °C was the most efficient with the CO2 solubility of 0.218. Thermodynamic modeling was performed by employing the nonrandom two liquids activity coefficient model and the Peng–Robinson equation of state for the liquid and gas phases, respectively. The Henry’s law constant was determined from experimental data. CO2 physical absorption was confirmed via nuclear magnetic resonance (NMR) and Fourier-transform infrared (FT-IR) analyses. TPAB-Fa (1:2), as the superior DES, exhibited regeneration efficiency of 99% after five absorption/desorption cycles.

Abstract A gentisic acid based-Deep Eutectic Solvent (MTPPBr/GA-DES) was synthesized by mixing one mole of methyl triphenylphosphonium bromide (MTPPBr) and one mole of gentisic acid (GA: 2,5-dihydroxy-benzoic acid) based on the eutectic point phase diagram. Then, it was characterized by FT-IR, NMR, densitometer, and TGA/DTA techniques and used as a potent and novel catalyst for the fast and green synthesis of: (i) Five new 2(a-e) and five known 2(f-j) benzo[6,7]chromeno[2,3-d]pyrimidines and (ii) One new (3a) and eleven known 3(b-l) pyrano[2,3-d]pyrimidines, in solvent-free conditions, short reaction times, and high yields. It is important to mention that for the synthesis of 2(a-j), there is only one reference which states that the reaction times are extremely long (720–2400 min), while these times are reduced to approximately 35–50 min in our proposed strategy, indicatinging that the rate of reactions will be 20–48 times faster, which is the clear and most obvious advantage of our approach.

The production of industrial chemicals with renewable biomass feedstock holds potential to aid the world in pursuing a carbon-neutral society. Trimellitic and trimesic acids are important commodity chemicals in industry that are prepared by the oxidation of petroleum-derived trimethylbenzene. To reduce the dependence on the limited oil source, we develop a potential sustainable alternative towards trimellitic and trimesic acids using biomass-based 2-methyl-2,4-pentandiol (MPD), acrylate and crotonaldehyde as starting materials. The process for trimellitic acid includes dehydration/D-A reaction of MPD and acrylate, flow aromatization over Pd/C catalyst, hydrolysis and catalytic aerobic oxidation (60% overall yield). The challenging regioselectivity issue of D-A reaction is tackled by a matched combination of temperature and deep eutectic solvent ChCl/HCO2H. Crotonaldehyde can also participate in the reaction, followed by Pd/C-catalyzed decarbonylation/dehydrogenation and oxidation to provide trimesic acid in 54% overall yield. Life cycle assessment implies that compared to conventional fossil process, our biomass-based routes present a potential in reducing carbon emissions.

Deep eutectic solvents (DESs) have emerged as viable alternatives to toxic organic solvents. The most intriguing aspect of these solvents is perhaps the widely varying physicochemical properties emerging from the changes in the constituents that form DESs along with their composition. Based on the constituents, a DES can be hydrophilic/polar or hydrophobic/non-polar, rendering a vastly varying spectrum of polarity a possibility. DESs formed by mixing urea (U) with hydrated lanthanide salts, lanthanum nitrate hexahydrate (La : U), cerium nitrate hexahydrate (Ce : U), and gadolinium nitrate hexahydrate (Gd : U), respectively, exhibit very high polarity as manifested via the probe-reported empirical parameters of dipolarity/polarizability (π*). The highest π* of 1.70 exhibited by the DES (Gd : U) in a 1 : 2 molar ratio is unprecedented. The π* ranges from 1.50 to 1.70 for these DESs, which is almost the highest reported for any solvent system. The π* decreases with an increasing amount of urea in the DES; however, the anomalous trends in H-bond donating acidity (α) and H-bond accepting basicity (β) appear to be due to the hydrated water of the lanthanide salt. The emission band maxima of the fluorescence probe of the “effective” dielectric constant (εeff) of the solubilizing media, pyrene-1-carboxaldehyde (PyCHO), in salt-rich DESs reflect higher cybotactic region dipolarity than that offered by water. Probe Nile red aggregates readily in these DESs to form non-fluorescent H-aggregates, which is a characteristic of highly polar solvents. The behavior of probe pyranine also corroborates these outcomes as the (lanthanide salt : urea) DES system supports the formation of the deprotonated form of the probe in the excited state. The (lanthanide salt : urea) DES system offers solubilizing media of exceptionally high polarity, which is bound to expand their application potential.

Abstract MTPPBr/THFTCA-DES was prepared as a new deep eutectic solvent (DES) from a mixture (molar ratio 7:3) of methyltriphenyl-phosphonium bromide (MTPPBr) and tetrahydrofuran-2,3,4,5-tetra-carboxylic acid (THFTCA), and characterized with various spectroscopic techniques, densitometer, and eutectic point. Then, it was used as a new and powerful catalyst for the synthesis of two sets of biologically important compounds, namely the Henna-based benzopyranophenazines and benzoxan-thenetriones. Solvent-free conditions, short reaction time, high efficiency, and easy recycling and separation of the DES catalyst are among the most important features of the presented method. Also, there is a nice consistency between the proposed structure of the DES compound, the integration values of the 1H NMR peaks, and the ratio of MTPPBr to THFTCA obtained from the eutectic point phase diagram. In addition, the reduction of peak splitting patterns in DES compared to the two primary materials can be good evidence of the formation of hydrogen bonds between the two components.

Abstract Deep eutectic solvents (DES) are a generation of ionic liquids that benefit from low cost, good stability, and environmental-friendly features. In this research, a porous silica gel was impregnated with a eutectic Choline Chloride-Monoethanolamine solvent (ChCl-MEA) to greatly improve its CO2 capture performance. In the impregnation, the weight percentages of ChCl-MEA were used in the range of 10–60 wt% at a temperature of 25 °C. The effect of ChCl-MEA loading on the structural properties of the DES-modified silica samples was studied by BET, FTIR, and TGA analyses. Investigation of the CO2 adsorption performance at different operational conditions showed that the modified silica gel with 50 wt% ChCl-MEA (Silica-CM50) presents the highest CO2 capture capacity of 89.32 mg/g. In the kinetic modeling, the fractional order model with a correlation coefficient of 0.998 resulted in the best fit with the experimental data. In addition, the isotherm data for Silica-CM50 were well-fitted with the Dual site Langmuir isotherm model with a correlation coefficient of 0.999, representing two distinct sites for the adsorption process. Moreover, the thermodynamic parameters including Enthalpy, Entropy, and Gibbs free energy at 25 °C were obtained to be − 2.770, − 0.005 and − 1.162, respectively. The results showed the exothermic, spontaneous and feasibility of the adsorption process.

The reaction of copper(II) oxalate and hexamethylenetetramine in a deep eutectic solvent made of urea and choline chloride produced crystals of pentaaminecopper(II) dichloride–urea (1/1), [Cu(NH3)5]Cl2·CO(NH2)2, which was characterized by single-crystal X-ray diffraction. The complex contains discrete pentaaminecopper(II) units in a square-based pyramidal geometry. The overall structure of the multi-component crystal is dictated by hydrogen bonding between urea molecules and amine H atoms with chloride anions.

Deep eutectic solvents (DES) were prepared by precise combinations of mol fractions of chemical compounds, resulting in a lowered melting point due to hydrogen bonding. This research aimed to elucidate the physicochemical attributes of DES and its effectiveness in mitigating free fatty acid (FFA) levels in crude palm oil (CPO). Zinc(II) chloride (ZnCl2) served as the hydrogen bond acceptor (HBA) while diethylene glycol (DEG) as the hydrogen bond donor (HBD). Characterization included freezing point, density, viscosity, conductivity, and pH determination. At a ZnCl2 mol fraction of 0.30, the resulting DES exhibited homogeneity with transparent liquid properties, featuring a freezing point below −10 °C, density of 1.42 g/mL, viscosity of 1933.40 cP, conductivity of 66.13 µS/cm, and pH 3.42. FTIR spectra confirmed hydrogen bond interactions between HBA and HBD. Applied to CPO at a 1:1 volumetric ratio (DES:CPO), with 2 h of stirring time at 50 °C, FFA content decreased from 4.11 to 0.86%. This research highlights DES as an environmentally sustainable purification agent, significantly reducing FFA levels in unrefined palm oil.

Abstract Oxidative desulfurization (ODS) has emerged as a prominent technique for the removal of sulfur compounds from fuels, aiming to comply with stringent environmental regulations and minimize sulfur dioxide emissions. Herein, Fenton-like deep eutectic solvents (DESs) were synthesized as a catalyst and reaction medium and their application for the ODS process was investigated. The study encompassed the optimization of DES composition, reaction conditions, and the influence of different parameters on the desulfurization efficiency. The experimental findings demonstrated that the Fenton-like DES exhibited outstanding catalytic activity in the oxidative desulfurization of fuel. The optimized conditions involved conducting the reaction at room temperature for 2.5 h, using 200 mg of the prepared DES (HNFM-FeCl4) as both the extraction solvent and catalyst. An oxidant-to-sulfur (O/S) ratio of approximately 3:1 was maintained, with a 30 wt% H2O2 solution utilized as the oxidant. The analysis of the reaction products using GC–MS revealed a remarkable yield of 98% for dibenzothiophene sulfone. The DES provided a suitable medium for the reaction, enhancing the solubility and availability of sulfur compounds. The iron catalyst, in the presence of hydrogen peroxide, facilitated the oxidation of sulfur-containing compounds to their corresponding sulfones, which can be easily separated from the fuel phase. The DES catalysts exhibited stability and recyclability, making them suitable for practical applications in fuel desulfurization processes.

A leading cause of global warming is the increase of carbon dioxide (CO2) emissions due to anthropogenic activities which prompts an urgent need for substantial reduction. Recently, CO2 absorption in deep eutectic solvents (DESs) has attracted scientific attention, because of their adaptability compared to traditional ionic liquids and aqueous amine solutions. This study employs the heating method to synthesize DESs using tetrapropylammonium bromide (TPAB) and formic acid (Fa) with molar ratios of TPAB-Fa (1:1) and TPAB-Fa (1:2). Absorption experiments by static method quantified CO2 solubility in the DESs under varied pressures and temperatures. TPAB-Fa (1:2) at 25.0 °C was the most efficient with the CO2 solubility of 0.218. Thermodynamic modeling was performed by employing the nonrandom two liquids activity coefficient model and the Peng–Robinson equation of state for the liquid and gas phases, respectively. The Henry's law constant was determined from experimental data. CO2 physical absorption was confirmed via nuclear magnetic resonance (NMR) and Fourier-transform infrared (FT-IR) analyses. TPAB-Fa (1:2), as the superior DES, exhibited regeneration efficiency of 99% after five absorption/desorption cycles. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) are increasingly recognized as sustainable alternatives suitable for a range of industrial applications. A precise comprehension of their properties is important for progress in science and engineering. In this study, we synthesized four novel ternary DESs using mandelic acid and measured their densities and viscosities at temperatures ranging from 298 to 353 K. Subsequently, an artificial neural network model was developed to predict DES density and viscosity based on temperature, critical properties, acentric factor, and molar ratio. The neural network parameters were optimized using experimental data from synthesized DESs and literature sources, both collectively over 500 data points for density and viscosity. Additionally, we investigated the influence of input parameters on model accuracy and assessed their significance. The results show that the average percentage relative error was 0.501 for density and 4.81 for viscosity. This research helps advance science and engineering applications of DESs. [ABSTRACT FROM AUTHOR]

Low mechanical properties and easy detachment from the hydration layer at the wet interface of hydrogel limit its application as an adhesive‐flexible sensor. In this study, the composition and structure of mussel mucoprotein are replicated using sulfonyl betaine (SBMA) containing zwitterion and N‐hydroxyethyl acrylamide to be polymerized in deep eutectic solvents and integrated with a polydopamine network to create a bionic eutectic gel with exceptionally strong and wet adhesion. Water erosion is effectively inhibited by the extensive hydrogen bond and electrostatic interactions. These dynamic bonds also impart self‐healing properties to the gel, showing a self‐healing efficiency of 55.45% after 48 h healing at room temperature. The zwitterion in SBMA can preferentially react with water to form a hydrated shell to protect the hydrogen bonds and enhance the exceptional water resistance and adhesion of the gel. The peel strength of the gel on a wet substrate is up to 220.71 N m−1, and its tensile strength can reach 1.01 MPa. It also has good mass stability at both low and high temperatures. This eutectic gel has the potential to be used in flexible electronic devices and can detect human movement and bioelectrical impulses on wet skin with great sensitivity. [ABSTRACT FROM AUTHOR]

It remains a great challenge to achieve strong and reversible hydrogel adhesion. Hydrogel adhesives also suffer from poor environmental stability due to dehydration. To overcome these problems, here reversible adhesive gels are designed using a new switching mechanism and new solvent. For the first time, the study observes UCST (upper critical solution temperature)‐type thermosensitive behaviors of poly(benzyl acrylate) (PBnA) polymer and gel in menthol:thymol deep eutectic solvents (DESs). The temperature‐induced phase transition allows adjusting cohesive force, and hence adhesion strength of PBnA gels by temperature. To further improve the mechanical and adhesion properties, a peptide crosslinker is used to allow energy dissipation when deforming. The resulting eutectogel exhibits thermal reversible adhesion with a high switching ratio of 14.0. The adhesion strength at attachment state reaches 0.627 MPa, which is much higher than most reversible adhesive hydrogels reported before. The low vapor pressure of DES endows the gel excellent environmental stability. More importantly, the gel can be repeatedly switched between attachment and detachment states. The strong and reversible gel adhesive is successfully used to design soft gripper for the transport of heavy cargos and climbing robot capable of moving on vertical and inverted surface in a manner similar to gecko. [ABSTRACT FROM AUTHOR]

A gentisic acid based-Deep Eutectic Solvent (MTPPBr/GA-DES) was synthesized by mixing one mole of methyl triphenylphosphonium bromide (MTPPBr) and one mole of gentisic acid (GA: 2,5-dihydroxy-benzoic acid) based on the eutectic point phase diagram. Then, it was characterized by FT-IR, NMR, densitometer, and TGA/DTA techniques and used as a potent and novel catalyst for the fast and green synthesis of: (i) Five new 2(a-e) and five known 2(f-j) benzo[6,7]chromeno[2,3-d]pyrimidines and (ii) One new (3a) and eleven known 3(b-l) pyrano[2,3-d]pyrimidines, in solvent-free conditions, short reaction times, and high yields. It is important to mention that for the synthesis of 2(a-j), there is only one reference which states that the reaction times are extremely long (720–2400 min), while these times are reduced to approximately 35–50 min in our proposed strategy, indicatinging that the rate of reactions will be 20–48 times faster, which is the clear and most obvious advantage of our approach. [ABSTRACT FROM AUTHOR]

Sphagnum palustre L. is a Chinese herbal medicine with a long history, however, few studies have been performed on its chemical composition and active effects. In this study, we investigated the composition and antibacterial and antioxidant capacities of extracts obtained from Sphagnum palustre L. phytosomes extracted with conventional solvents (water, methanol, and ethanol) and two different hydrogen bond donors (citric acid and 1,2-propanediol) modified with choline chloride-type deep eutectic solvents (DESs). The results show that Sphagnum palustre extracts contained 253 compounds, including citric acid, ethyl maltol, and thymol. The highest total phenolic content (TPC) was obtained with a DES extraction method combining 1,2-propanediol and choline chloride (39.02 ± 7.08 mg gallic acid equivalent/g dried weight (DW). This shows the composition of Sphagnum palustre as a natural product and the application of DESs in the extraction of active ingredients, demonstrating the potential of peat moss extracts in cosmetics and health products. [ABSTRACT FROM AUTHOR]

In this study, we investigate the electrochemical behavior of palladium nanoparticles (PdNP) deposition on glassy carbon electrode (GCE) in two deep eutectic solvents, namely, reline and ethaline, and its application in DNA sensors. The electrochemical behaviors of PdNP deposition are investigated by cyclic voltammetry and chronoamperometry. The obtained results indicate that the PdNP deposition on GCE in reline was dominated by the progressive 3D nucleation mechanism, while that in ethaline was dominated by the instantaneous nucleation mechanism. The structural, morphological, and compositional characteristics are also investigated through X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. A PdNP-based DNA sensor is constructed for Mycobacterium tuberculosis detection. Results indicate a significant difference between the DNA sensing responses based on the PdNPs synthesized in reline (PdNP-RE) and ethaline (PdNP-ET). The PdNP-ET–based DNA sensor has higher sensitivity than the PdNP-RE–based DNA sensor. This study serves as a reference for the development of improved nanomaterials for bioanalysis and the elaborate design of biosensors for practical applications. [ABSTRACT FROM AUTHOR]

A low-cost method for the simultaneous extraction of alkaloids and water-insoluble flavonoids and esters from Coptis chinensis Franch. (Abbrev. C. chinensis) was explored to provide a reference for the production of green plant-based preparations and traditional Chinese medicine formula granules. A combined extraction method with the deep eutectic solvents (DESs) of choline chloride and urea (molar mass ratio of 1:2) and organic solvent ethanol was used, supplemented by ultrasonic-assisted extraction (ultrasonic power: 150 W; ultrasonic temperature: 60 °C; treatment time: 15 min). The extraction efficiency of the 50% DES (choline chloride and urea) aqueous solution for berberine, palmatine, jatrorrhizine, and magnoflorine was found to be the highest and was superior to traditional ultrasonic extraction and water bath reflux extraction methods. Furthermore, the flavonoids and esters from C. chinensis residue were extracted using ethanol. The results from high-performance liquid chromatography and gas chromatography–mass spectrometry indicated a high extraction efficiency overall. [ABSTRACT FROM AUTHOR]

In the present work, deep eutectic solvents (DESs) were synthesized in a one-step process by heating the hydrogen bond acceptors (HBAs) tetrabutylammonium bromide and tetrabutylphosphonium bromide, along with two hydrogen bond donors (HBDs) ethanolamine and N-methyldiethanolamine, which were mixed in certain molar ratios. This mixture was then mixed with water to form a DES + water system. The densities of the prepared DES + water systems were successfully measured using the U-tube oscillation method under atmospheric pressure over a temperature range of 293.15–363.15 K. The CO2 trapping capacity of the DES + water systems was investigated using the isovolumetric saturation technique at pressures ranging from 0.1 MPa to 1 MPa and temperatures ranging from 303.15 K to 323.15 K. A semi-empirical model was employed to fit the experimental CO2 solubility data, and the deviations between the experimental and fitted values were calculated. At a temperature of 303.15 K and a pressure of 100 kPa, the CO2 solubilities in the DES + water systems of TBAB and MEA, with molar ratios of 1:8, 1:9, and 1:10, were measured to be 0.1430 g/g, 0.1479 g/g, and 0.1540 g/g, respectively. Finally, it was concluded that the DES + water systems had a superior CO2 capture capacity compared to the 30% aqueous monoethanolamine solution commonly used in industry, indicating the potential of DES + water systems for CO2 capture. [ABSTRACT FROM AUTHOR]

Lignin, the second most abundant natural polymer, is a by-product of the biorefinery and pulp and paper industries. This study was undertaken to evaluate the properties and estimate the prospects of using lignin as a by-product of the pretreatment of common reed straw (Phragmites australis) with deep eutectic solvents (DESs) of various compositions: choline chloride/oxalic acid (ChCl/OA), choline chloride/lactic acid (ChCl/LA), and choline chloride/monoethanol amine (ChCl/EA). The lignin samples, hereinafter referred to as Lig-OA, Lig-LA, and Lig-EA, were obtained as by-products after optimizing the conditions of reed straw pretreatment with DESs in order to improve the efficiency of subsequent enzymatic hydrolysis. The lignin was studied using gel penetration chromatography, UV-vis, ATR-FTIR, and 1H and 13C NMR spectroscopy; its antioxidant activity was assessed, and the UV-shielding properties of lignin/polyvinyl alcohol composite films were estimated. The DES composition had a significant impact on the structure and properties of the extracted lignin. The lignin's ability to scavenge ABTS+• and DPPH• radicals, as well as the efficiency of UV radiation shielding, decreased as follows: Lig-OA > Lig-LA > Lig-EA. The PVA/Lig-OA and PVA/Lig-LA films with a lignin content of 4% of the weight of PVA block UV radiation in the UVA range by 96% and 87%, respectively, and completely block UV radiation in the UVB range. [ABSTRACT FROM AUTHOR]

Lignin, an amorphous biomacromolecule abundantly distributed in the plant kingdom, has gained considerable attention due to its intrinsic bioactivities and renewable nature. Owing to its polyphenolic structure, lignin has a variety of human health activities, including antioxidant, antimicrobial, antidiabetic, antitumor, and other activities. The extraction of lignin from various sources in a green and sustainable manner is critical in the food industry. Deep eutectic solvent (DES) has recently been recognized as a class of safe and environmentally friendly media capable of efficiently extracting lignin. This article comprehensively reviews the recent advances in lignin extraction using DES, discusses the influential factors on the antioxidant activity of lignin, interprets the relationship between antioxidant activity and lignin structure, and overviews the applications of lignin in the food industry. We aim to highlight the advantages of DES in lignin extraction and valorization from the nutrition and food views. [ABSTRACT FROM AUTHOR]

In this study, we propose a novel strategy utilizing deep eutectic solvents (DESs) as both the extraction solvent and dispersing liquid, with nanometer zinc oxide (ZnO) serving as the adsorbent. This method incorporates ultrasound‐assisted matrix solid phase dispersion (UA‐MSPD) for the extraction of six active components (salidroside, echinacoside, acteoside, specnuezhenide, nuezhenoside G13, and oleanolic acid) from Ligustri Lucidi Fructus samples. The extracts were then analyzed using high‐performance liquid chromatography equipped with a diode array detector. The effects of various parameters such as dispersant dosage, DESs volume, grinding time, ultrasonication duration, and eluent volume on extraction recovery were investigated and optimized using a central composite design under response surface methodology. The optimized conditions yielded detection limits ranging from 0.003 to 0.01 mg/g and relative standard deviations of 8.7% or lower. Extraction recoveries varied between 93% and 98%. The method demonstrated excellent linearity for the analytes (R2 ≥ 0.9997). The simple, green, and efficient DESs/ZnO‐UA‐MSPD technique proved to be rapid, accurate, and reliable for extracting and analyzing the six active ingredients in Ligustri Lucidi Fructus samples. [ABSTRACT FROM AUTHOR]

Indigo, one of the oldest dyes, finds widespread usage across multiple industries, encompassing food, medicine, printing, dyeing, as well as cosmetics. Indican is recognized as a precursor substance crucial for the synthesis of indigo, however, the current indican extraction and indigo preparation are largely limited due to the low efficiency of indican extraction, by-product production, as well as serious environmental pollution. To address the serial of issues, we developed deep eutectic solvent (DESs)-oriented integration of the efficient extraction of indican and the green preparation of indigo from Strobilanthes cusia (Nees) Kuntze. DESs were rationally designed and screened to make them able to destroy cell walls to facilitate the precipitation of the desired substance for specific indican extraction. And then optimized to obtain the final extraction rate of 22.8 mg/g, which present the highest so far. More importantly, without additional treatment for DES-containing indican extractive, the β-glucosidase Asbg1 was able to convert indican to indigo at a molar conversion rate of 74.6%. By fully harnessing plant resources, the study introduced an innovative process that bypassed extreme acid-base conditions, ensuring rapidness and minimal pollution. This approach offered a promising avenue for the preparation of indigo, paving the way for sustainable production methods. [Display omitted] • Selected and reasonably designed DESs to realize green extraction of indican. • An extraction rate of indican, present the highest so far, was achieved. • Established an eco-friendly strategy of indigo production based on plants. [ABSTRACT FROM AUTHOR]

A novel magnetic dispersive solid phase extraction (MDSPE) procedure based on the deep eutectic solvent (DES) modified magnetic graphene oxide/metal organic frameworks nanocomposites (MGO@ZIF-8@DES) was established and used for the efficient enrichment of estradiol, estrone, and diethylstilbestrol in cosmetics (toner, lotion, and cream) for the first time. Then, the three estrogens were separated and determined by UHPLC-UV analysis method. In order to study the features and morphology of the synthesized adsorbents, various techniques such as FT-IR, SEM, and VSM measurements were executed. The MGO@ZIF-8@DES nanocomposites combine the advantages of high adsorption capacity, adequate stability in aqueous solution, and convenient separation from the sample solution. To achieve high extraction recoveries, the Box-Behnken design and single factor experiment were applied in the experimental design. Under the optimum conditions, the method detection limits for three estrogens were 20–30 ng g−1. This approach showed a good correlation coefficient (r more than 0.9998) and reasonable linearity in the range 70–10000 ng g−1. The relative standard deviations for intra-day and inter-day were beneath 7.5% and 8.9%, respectively. The developed MDSPE-UHPLC-UV method was successfully used to determine three estrogens in cosmetics, and acceptable recoveries in the intervals of 83.5–95.9% were obtained. Finally, three estrogens were not detected in some cosmetic samples. In addition, the Complex GAPI tool was used to evaluate the greenness of the developed pretreatment method. The developed MDSPE-UHPLC-UV method is sensitive, accurate, rapid, and eco-friendly, which provides a promising strategy for determining hormones in different complex samples. [ABSTRACT FROM AUTHOR]

A novel Deep Eutectic Solvent (MTPPBr/HGA-DES) was prepared by a mixture of methyl triphenylphosphonium bromide (MTPPBr) and hypogallic acid (HGA: 2,3-dihydroxybenzoic acid). The eutectic point phase diagram showed that the one mole of MTPPBr to two moles of HGA is the best mole ratio for the synthesis of a novel DES. Then, MTPPBr/HGA-DES was characterized by the FT-IR, TGA/DTA, densitometer, eutectic points, and 1H NMR techniques, and used as a novel catalyst for the green synthesis of new pyrano[2,3-d]pyrimidines 2(a-j)via a one-pot four-component condensation reaction of 4-hydroxycoumarin, barbituric acid, morpholine and benzaldehydes at 80 °C in solvent-free conditions. [ABSTRACT FROM AUTHOR]

Nucleic acids have the ability to generate advanced nanostructures in a controlled manner and can interact with target sequences or molecules with high affinity and selectivity. For this reason, they have applications in a variety of nanotechnology applications, from highly specific sensors to smart nanomachines and even in other applications such as enantioselective catalysis or drug delivery systems. However, a common disadvantage is the use of water as the ubiquitous solvent. The use of nucleic acids in non-aqueous solvents offers the opportunity to create a completely new toolbox with unprecedented degrees of freedom. Ionic liquids (ILs) and deep eutectic solvents (DESs) are the most promising alternative solvents due to their unique electrolyte and solvent roles, as well as their ability to maintain the stability and functionality of nucleic acids. This review aims to be a comprehensive, critical, and accessible evaluation of how much this goal has been achieved and what are the most critical parameters for accomplishing a breakthrough. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Deep eutectic solvent (DES) has been identified as a potential green solvent in biomass processing. In the present investigation, a deep eutectic solvent i.e. choline chloride: urea (ChCl/U) was synthesized and employed to pretreat rice husks. Plackett- Burman response surface methodology was used to optimize the factors which are DES molar ratio, residence time, temperature, and biomass concentration. A total of 11 experimental conditions were evaluated and the highest amount of reducing sugar was obtained when 2 g rice husk was pretreated with 1:2 ChCl/U at 80°C for 6 h i.e. 0.67 ± 0.05 mg/mL. Furthermore, scanning electron microscopy (SEM), Fourier transforms infrared (FTIR), and X-ray diffraction (XRD) studies were used to characterize the structural and compositional changes in which DES demonstrates a great performance in the pretreatment of rice husk by eliminating amorphous lignin and hemicellulose content. Therefore, the facile process used in this study has the potential to be used on a massive scale to produce fermentable sugars and other compounds. [ABSTRACT FROM AUTHOR]

In this paper, lignocellulose components were separated under mild conditions to achieve hierarchical utilization of biomass. Cellulose was retained in cellulose pulp with highly crystalline structure, and lignin powder was recovered, which offered a possibility for the high-value utilization of lignocellulosic biomass. The extracted lignin (EL) was carbonized and activated to prepare lignin-based porous carbon microspheres (LPCMs) and further used as a substrate to interact with fluorescein-5-isothiocyanate (5-FITC) for the detection of biogenic amines (BAs). The fluorescence of 5-FITC was found to be quenched in the presence of LPCMs. And then, upon addition of BAs, 5-FITC was released from the surface of LPCMs, which resulted in the fluorescence recovery of 5-FITC. Thus, a novel "turn off–on" fluorescent probe was constructed for sensitive and visual detection of BAs. Meanwhile, the retained cellulose skeleton structure was used to prepare a smart identification label for real-time and visual evaluation of the freshness of pork and shrimp. This work realized the improvement of comprehensive utilization rate of lignocellulose and developed a rapid, efficient, and sustainable method which combined natural lignocellulose materials with green analytical technology for visually evaluating food quality. [ABSTRACT FROM AUTHOR]

The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric materials. In this work, serials of deep eutectic solvents (DES) with intermolecular-hydrogen-bonding interaction were constructed as catalysts and medium for actuating reversible complexation-mediated polymerization (RCMP) for the first time, yielding methacrylate polymers with high monomer conversion and narrow dispersion molecular weight in both water and oil systems. The mechanism and elementary reaction of RCMP were explored deeply, revealing that the complexation of initiator with DES to generate radicals was a ratecontrolling step and intermolecular-hydrogen-bond was primary factor to influence polymerization rate. Moreover, the insights of density functional theory calculations revealed that negative electrostatic potential ensured nucleophilic capacity. This investigation demonstrated the considerable potential of DES for RCMP, which is anticipated for other polymerization applications as a novel medium mode. [ABSTRACT FROM AUTHOR]

Steam flooding is easily induced to transverse flow, with a limited swept area and low displacement efficiency. Therefore, chemical agents have been used to assist in steam flooding for heavy oil extraction. However, research into the driving mechanisms and modes of occurrence of residual oil is insufficient. In this work, a flooding simulation was conducted to understand the occurrence mechanism of residual oil during the flooding process in heavy oil reservoirs. First, the foam properties of a novel DES (Deep Eutectic Solvent) and CTAB (Cetyltrimethyl Ammonium Bromide) composite system with ultra-low interfacial tension were tested. The optimal concentration and gas–liquid ratio of the foam agent solution were determined. Secondly, the NFAS (N2 foam-assisted steam flooding) was carried out after steam flooding, and the flow behavior of crude oil at different flow pathway zones was researched. In the end, the remaining oil morphology and distribution characteristics under different displacement times were analyzed, determining the mode of remaining oil occurrence during NFAS flooding. The results show that (1) the novel DES and CTAB system has good foam properties. The best concentration is 0.5 wt%, and the optimal ratio of gas to liquid is 1:1. (2) In the steam flooding stage, the columnar remaining oil in the narrow hole near the flow pathway increases, and the cluster remaining oil in the far flow channel changes into film and columnar. (3) During NFAS displacement, the residual oil primarily presents a state of fully mixing the O/W emulsion formed after blending and dispersing with oil, gas, and water. (4) After the NFAS flooding stage, the remaining oil was distributed in each throat. The remaining oil in the near passage is mostly blocked by foam in large holes with a pore coordination number of 4 and 5. The residual oil in the distant runner is distributed in the thick and middle throats. (5) NFAS flooding outperforms steam flooding by significantly decreasing residual oil in narrow passages of the main flow channel and near flow channels, resulting in a substantial 44.9% increase in overall recovery rate. [ABSTRACT FROM AUTHOR]

MTPPBr/THFTCA-DES was prepared as a new deep eutectic solvent (DES) from a mixture (molar ratio 7:3) of methyltriphenyl-phosphonium bromide (MTPPBr) and tetrahydrofuran-2,3,4,5-tetra-carboxylic acid (THFTCA), and characterized with various spectroscopic techniques, densitometer, and eutectic point. Then, it was used as a new and powerful catalyst for the synthesis of two sets of biologically important compounds, namely the Henna-based benzopyranophenazines and benzoxan-thenetriones. Solvent-free conditions, short reaction time, high efficiency, and easy recycling and separation of the DES catalyst are among the most important features of the presented method. Also, there is a nice consistency between the proposed structure of the DES compound, the integration values of the 1H NMR peaks, and the ratio of MTPPBr to THFTCA obtained from the eutectic point phase diagram. In addition, the reduction of peak splitting patterns in DES compared to the two primary materials can be good evidence of the formation of hydrogen bonds between the two components. [ABSTRACT FROM AUTHOR]

Metal oxides have applications in a variety of different fields, and new synthesis methods are needed to control their properties and improve their performance as functional materials. In this study, we investigated a low-cost antisolvent precipitation method using a choline chloride-urea deep eutectic solvent to precipitate CuZnOx materials using water as the antisolvent. Using this methodology, the metal oxide materials can be precipitated directly from the deep eutectic solvent without the need for a high-temperature calcination step that can lead to a reduction in defects and surface area, which are important properties in applications such as catalysis. [ABSTRACT FROM AUTHOR]

A red dragon fruit peel (DFP) contributes to 30–35% of total fruit weight and is disposed of as waste by the fruit processing industries, despite the fact that it contains bioactive compounds with nutritional properties. Ultrasound-assisted deep eutectic solvent (DES) extraction of DFP was performed for the extraction of betanin. From the parametric study, ChCl–ethylene glycol was chosen for further optimization. Extraction parameters were screened using the Plackett–Burman design. Box–Behnken design was applied to get the optimum condition of 40% cycle time, 40% water concentration, and 5 min extraction time to obtain total betanin content of 10.2 mg/10 g dry wt. DFP was valorized to chitosan-based antioxidant films. % DPPH, and % ABTS radical scavenging activity of extract incorporated film was better than control film. Thermogravimetric analysis (TGA) confirmed biofilms could be used safely at food temperature (up to 145 °C). FTIR analysis confirmed the functional group of extract in the chitosan films. With the addition of DES extract, the water vapor permeability and water solubility increased to 3.59 × 10-10 g m-1 s-1 Pa-1 and 47.03%, respectively. The thickness of the film also increased because of the enlargement of space between polymer chains. The elasticity of the films increased by 192.40%, indicating that the DES extract was successfully incorporated as a plasticizer. The tensile strength decreased to 12.46 MPa because of the interaction of DES with the –OH group of chitosan, which disrupts polymer chain bonds. Therefore, bio-refining of waste peel can be advantageous for managing waste disposal and reducing plastic pollution. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present study, a dispersive solid-phase extraction based on colloidal gel is presented for rapid/efficient determination of ethalfluralin with high precision and accuracy. The synthesis of colloidal gel was accomplished by combining manganese dioxide (MnO2) nanoparticles with the deep eutectic solvent (DES) as the preferred ionic fluid. Using a one-factor-at-a-time approach, variables affecting the extraction efficiency of the developed method were optimized to achieve the highest extraction efficiency and stability for the determination of the target analyte. In line with data obtained, the limit of detection value for the target analyte was determined to be 10.2 µg/kg. In order to demonstrate the accuracy/applicability of the developed method in complex matrices, different soy flour samples were utilized, and extraction procedures were conducted under pre-determined optimal method conditions. Matrix matching calibration strategy was applied to spiked samples, followed by the determination of percent recovery results ranging between 92.1 and 114.2%. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DES) are a generation of ionic liquids that benefit from low cost, good stability, and environmental-friendly features. In this research, a porous silica gel was impregnated with a eutectic Choline Chloride-Monoethanolamine solvent (ChCl-MEA) to greatly improve its CO2 capture performance. In the impregnation, the weight percentages of ChCl-MEA were used in the range of 10–60 wt% at a temperature of 25 °C. The effect of ChCl-MEA loading on the structural properties of the DES-modified silica samples was studied by BET, FTIR, and TGA analyses. Investigation of the CO2 adsorption performance at different operational conditions showed that the modified silica gel with 50 wt% ChCl-MEA (Silica-CM50) presents the highest CO2 capture capacity of 89.32 mg/g. In the kinetic modeling, the fractional order model with a correlation coefficient of 0.998 resulted in the best fit with the experimental data. In addition, the isotherm data for Silica-CM50 were well-fitted with the Dual site Langmuir isotherm model with a correlation coefficient of 0.999, representing two distinct sites for the adsorption process. Moreover, the thermodynamic parameters including Enthalpy, Entropy, and Gibbs free energy at 25 °C were obtained to be − 2.770, − 0.005 and − 1.162, respectively. The results showed the exothermic, spontaneous and feasibility of the adsorption process. [ABSTRACT FROM AUTHOR]

The capability of peptide and amino acid‐based molecules to act as ionogelators and eutectogelators entrapping ionic liquids (ILs) and deep eutectic solvents (DESs) forming ionogels and eutectogels has gathered attention in recent decades. The self‐assembly process, primarily driven by non‐covalent interactions as hydrogen bonding, remains serendipitous in nature. This review provides a comprehensive and detailed report on self‐assembly of unmodified and modified amino acids and peptides in the non‐conventional solvents, ILs and DESs. Understanding these processes holds great promise for the development of innovative soft‐materials, and to the progress of supramolecular systems in non‐conventional solvent environments. [ABSTRACT FROM AUTHOR]

This study aimed to develop composite hydrogels with exceptional piezoelectric properties and pressure sensitivity. To achieve the objective, this study created a deep eutectic solvent (DES) by mixing choline chloride (ChCl), acrylamide (AM), and acrylic acid (AA). Barium titanate nanoparticles (BTNPs) were incorporated as fillers into the deep eutectic solvents (DES) to synthesize the composite hydrogels using frontal polymerization (FP). The mechanical and piezoelectric properties of the resulting composite hydrogels were analyzed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). This study found that the BTNPs/P(AM-co-AA) composite hydrogels exhibited excellent mechanical and piezoelectric properties. This is attributed to the high dielectric constant of BTNPs and the electrode polarization phenomenon when subjected to pressure. With a BTNPs content of 0.6 wt%, the maximum compressive strength increased by 3.68 times compared with the hydrogel without added BTNPs. Moreover, increasing the BTNPs content to 0.6 wt% resulted in a 1.48 times increase in generated voltage under the same pressure, compared with the hydrogel with only 0.2 wt% BTNPs. This study provides a method for preparing composite hydrogels with outstanding piezoelectric properties and pressure sensitivity. [ABSTRACT FROM AUTHOR]