Mixture Of Choline Chloride Research Articles

Hydrodynamic Voltammetry of Fe2+/3+ Redox Couple in Eutectic Electrolytes for Flow Batteries

Deep eutectic solvents (DESs) demonstrate potential as non-aqueous electrolytes for next-generation redox flow batteries (RFBs). DESs are considered not only as environmentally sustainable but also economically attractive electrolytes because they can be resourced from biological feedstock (alcohols, urea, choline) and are earth-abundant and of low toxicity. However, their inherent hydrogen bonding leads to high viscosity, hindering ion and reactant transport, thereby limiting power density. This study investigates the influence of controlled water addition on the Fe²⁺/Fe³⁺ redox couple in DES ethaline (a mixture of choline chloride and ethylene glycol in 1:2 molar ratio) to gradually disrupt the hydrogen bond network between its components. Our results show that the stoichiometric introduction of water effectively reduces viscosity and increases ionic conductivity within the DES electrolyte. The reduced viscosity and three-fold improvement in conductivity enhances mass transport and kinetics of Fe²⁺/Fe³⁺ redox couple in DES ethaline, potentially leading to higher power density RFBs. Also, iron chloride salts exhibit increasing solubility (>2 M) in DES electrolyte with the addition of increasing quantities of water. Notably, the electrochemical stability window remains around 1.90 V, mitigating concerns about water-induced instabilities. These findings suggest that strategically incorporating water into DES electrolytes can overcome mass transport limitations, paving the way for high-performance, environmentally friendly RFBs. This approach eliminates the need for harmful solvents and fossil fuel-based processes.

Development of Green Extraction Using Natural Deep Eutectic Solvent (NADES) for Separation Polyphenolic Compounds from Spilanthes acmella

Natural deep eutectic solvent (NADES) is an alternative to conventional solvents in polyphenol extraction. Its composition of choline chloride combined with fructose, choline chloride with lactic acid, choline chloride with glycerol, choline chloride with propylene glycol, and choline chloride with proline have been sucessfully set using the thermal mixing method. Choline chloride served as the hydrogen bond acceptor (HBA), while the others acted as hydrogen bond donors (HBDs) at a mole ratio of 1:2. This study aimed to extract polyphenols from the flowers, stalks, stems, and leaves of Spilanthes acmella, using NADESs. The extraction process was conducted by adding 20% water to the mixture with a ratio of the sample to solvent of 1:10 (w/v), for 60 min. The extract concentration was assessed through spectroscopic photometry using the Folin-Ciocalteu method. The result showed that the choline chloride-glycerol NADES was the most appropriate solvent for the extraction of polyphenols from the flowers of the plant. Meanwhile, the best NADES for the extraction from the stems, stalks, and leaves, was the mixture of choline chloride and fructose. The highest polyphenol concentration was obtained in the stems at 2545.192 mg/L. The yield obtained in the stems, leaves, stalks, and flower were 25.452, 6.284, 3.111 and 2.415 mg gallic acid equivalent/g (GAE/g), respectively. These findings suggest that NADES can be used as an eco-friendly alternative solvent for green extraction processes of active compounds from natural materials, especially polyphenols from S. acmella.

ЕЛЕКТРОХІМІЧНЕ ОСАДЖЕННЯ НАНОКРИСТАЛІЧНОГО КОМПОЗИТУ НІКЕЛЬ–ЦЕРІЮ(IV) ОКСИД З НИЗЬКОТЕМПЕРАТУРНОГО ЕВТЕКТИЧНОГО РОЗЧИННИКА ДЛЯ ВИГОТОВЛЕННЯ ЕЛЕКТРОКАТАЛІЗАТОРІВ ДЛЯ ВОДНЕВОЇ ЕНЕРГЕТИКИ

This study reports the patterns of electroplating a composite coating containing phases of nanocrystalline metallic nickel and cerium dioxide from an electrolyte based on a new generation of ionic liquids, deep eutectic solvents (DESs). Currently, the use of DESs is an extremely promising direction for the electrochemical deposition of electrocatalytic coatings for electrochemical energy, particularly for "green" hydrogen energy. The electrolyte for deposition contained a liquid eutectic mixture of choline chloride and urea (the so-called "reline", a typical representative of DESs), in which nickel (II) chloride (0.1 mol/dm³) and cerium (III) chloride (0.2–0.4 mol/dm3) were dissolved. According to the results of energy-dispersive X-ray analysis and XRD investigations, the composite coating contains approximately 12–16 at.% cerium, presumably in the form of cerium dioxide. A reaction scheme for the formation of the composite nanocoating, which includes a combination of chemical and electrochemical stages, is proposed. It was found that the incorporation of cerium oxide leads to a significant increase in electrocatalytic activity (compared to nickel coating) in the cathodic hydrogen evolution reaction and anodic oxygen evolution and urea oxidation reactions. It is hypothesized that the observed enhancement in electrocatalytic effect is due to the formation of additional active catalytic sites on the surface containing cerium in different oxidation states (e.g., Ce(+4)/Ce(+3)), which can act as electron carriers in both cathodic and anodic reactions. A significant advantage of this composite is its bifunctionality as an electrocatalyst, meaning it can be used for both cathodic and anodic processes. The obtained results can be used in the development of new high-efficiency processes for the electrochemical synthesis of "green" hydrogen.

Valorization of Waste Wool to Keratin with a Green Solvent Based on a Deep Eutectic Mixture of Choline Chloride and Lactic Acid

Abstract Waste wool, a by-product of sheep husbandry, is primarily composed of keratin, which has potential use in cosmetic products, biotechnology and medical applications. Traditional chemical methods for keratin extraction face limitations due to health and environmental concerns, and thus, green alternatives such as deep eutectic solvents (DESs) have been developed. The aim of the present study was to determine whether a natural DES composed of choline chloride and lactic acid can be used to extract keratin from sheep wool. The dissolution and keratin yield were investigated under different reaction times, temperatures, and wool-to-DES ratios. Fractions of water-soluble keratin and water-insoluble keratin aggregates were obtained by dialysis, centrifugation, and drying. The results showed that both the dissolution of wool and the yield of recovered keratin increased as the reaction time and temperature increased from 1 to 8 h and from 80 to 110 $$^{\circ }$$ ∘ C, respectively. With the longest reaction time of 8 hours and the highest temperature of 110 $$^{\circ }$$ ∘ C, the yield of water-soluble keratin increased to 23 %. Characterizations revealed that DES detached first the cuticular scales from the surface of wool fibres and subsequently degraded wool cortex layer. The extracted water-soluble keratin retained the characteristic amide structure of wool, but the secondary structure of keratin was converted to cross-$$\beta$$ β sheet form. Moreover, it had a narrow size distribution and a molecular weight of 10 kDa. The results of this study indicate that the proposed DES can be used as a green solvent for recovering keratin from sheep wool. Graphical Abstract

Breakthrough Conductivity Enhancement in Deep Eutectic Solvents via Grotthuss‐Type Proton Transport

AbstractThere is an increasing demand for the development of ion‐conducting electrolytes for energy storage systems. Much attention is directed toward deep eutectic solvents as potential candidates. In the search for highly conductive systems, the possibility of designing deep eutectic solvents with Grotthuss‐type proton transport is widely overlooked. Herein, ethaline, a mixture of choline chloride and ethylene glycol is used in a 1:2 molar ratio, to induce a significant conductivity increase with the addition of water and sulfuric acid (H2SO4). The achieved breakthrough conductivity is analyzed experimentally and simulated with ab initio molecular dynamics (AIMD). At sufficient water content, an H‐bonding network is formed that leads to a significant breakthrough conductivity based on H2SO4‐derived proton transfer following the long‐established Grotthuss proton transport mechanism. This result is substantiated by the positive deviation from the ideal KCl line in the Walden plot. Specifically, the data series positioned above the reference line indicates a Grotthuss mechanism in action. The AIMD simulations demonstrate proton transfer between water and ethylene glycol, supported by simulation frames captured at various times.

Influence of anodic treatment of a copper-nickel alloy in a eutectic mixture of choline chloride and urea on the surface morphology and electrocatalytic behavior in the hydrogen evolution reaction

For the first time, we investigated the process of potentiostatic anodic treatment of the surface of a copper (≈55%)-nickel alloy in a eutectic mixture of urea and choline chloride (reline), which is a typical representative of a new generation of ionic liquids, deep eutectic solvents. The anodic behavior of the alloy in the used solvent was characterized by cyclic voltammetry, and the nature of the electrochemical dissolution reactions of individual components of the alloy corresponding to several anodic current waves registered in voltammograms was determined. It was established that the anodic dissolution of the alloy occurs under conditions of salt surface passivation due to the formation of a layer of poorly soluble products of the electrode reaction. It was shown that under conditions of prolonged (150 min) potentiostatic polarization of the alloy in reline for various values of the electrode potential (in the range from 0.1 to 1.7 V relative to the Ag reference electrode), the chemical composition of the surface remained unchanged (i.e., there was no selective etching of individual components of the alloy), but an evolution of surface morphology patterns was observed, the specific type of which depended on the value of the applied potential. Anodic treatment of the Cu-Ni alloy in the reline solvent at any of the investigated anodic potentials led to an increase in the surface roughness coefficient, and electrochemical polishing did not occur. Analysis of kinetic data related to the hydrogen evolution reaction on the surfaces of reline-treated copper-nickel alloys in a 1 M NaOH aqueous solution showed a significant increase in exchange current density. This indicates enhancement of electrocatalytic activity compared to the untreated surface. The observed effect is likely associated with an increase in the true surface area of the alloy available for electrochemical reaction and an increase in the surface concentration of electrocatalytic sites resulting from the anodic dissolution of the alloy. The obtained results can be used in the development of highly efficient and relatively inexpensive electrocatalysts for hydrogen energy.

Influence of anodic treatment of nickel in deep eutectic solvents on electrocatalytic activity in oxygen evolution and urea oxidation reactions

The influence of anodic potentiostatic treatment of nickel surface in deep eutectic solvents, ethaline and reline (eutectic mixtures of choline chloride with ethylene glycol and urea, respectively), on the electrocatalytic activity in the electrochemical reactions of oxygen evolution and urea oxidation in an aqueous alkaline medium (1 M NaOH) was investigated for the first time. It was shown that, depending on the chosen treatment potential and the nature of the eutectic solvent used, a significant increase in the rate of the studied processes was observed. Specifically, after anodic treatment of nickel under certain conditions, the polarization of the oxygen evolution reaction at a current density of 0.1 A/cm2 could be reduced by approximately 150–200 mV, and the maximum current density of urea oxidation could be increased by an order of magnitude (from 0.012 A/cm2 to 0.131 A/cm2 at a urea concentration of 0.33 mol/dm3 in alkaline solution). The observed increase in electrocatalytic activity after anodic treatment of nickel in deep eutectic solvents is likely related to changes in surface morphology patterns and the nature and concentration of relevant electroactive sites on the electrode surface. The results obtained in this work can be used for the development of highly efficient electrode materials for green hydrogen energy.

Choline chloride-L-lactic acid mixtures as solvents for extraction of Coumarin from cinnamon-containing foods

The determination of coumarin in generally available cinnamon-containing foods such as biscuits, cereals is important to ensure that the populations consuming these foods more frequently are not exposed to higher levels and are not at risk. This study describes the development of an analytical method for determination of coumarin in foods containing cinnamon. Solid-liquid phase extraction with conventional stirring-assisted and ultrasound-assisted extraction (UAE) procedures were used to prepare sample extracts for liquid chromatography analysis. The green solvent, a mixture of choline chloride:L-lactic acid (1:4, mol/mol)/water (50:50 v/v), as a deep eutectic solvent-like mixture, was selected as an extraction solvent. The extraction conditions were optimized by using the design of the experiment strategy obtaining parameters, temperature 47 °C, time 36 min, solvent volume 4 mL, sample amount 0.8 g, stirring speed 20 rpm for rotary stirring-assisted extraction procedure, and temperature 30 °C, time 5 min, solvent volume 3.5 mL, sample amount 0.8 g for UAE. High-performance liquid chromatography separation with a total analysis time of 12 min was performed with a stationary phase of octadecyl type and a gradient of mobile phase of methanol-1 % acetic acid. The methods were successfully validated to show the detection limit of 0.13 μg.mL−1, the linearity range of 0.4–50 µg.mL−1 (R2 = 0.999), recovery values more than 80 %, and the RSDs of less than 7 %. Rotary stirring-assisted extraction showed moderately higher recovery values than UAE, while lower RSD % was observed for UAE.

A low-cost all-iron hybrid redox flow batteries enabled by deep eutectic solvents

Redox flow batteries (RFBs) emerge as highly promising candidates for grid-scale energy storage, demonstrating exceptional scalability and effectively decoupling energy and power attributes. Nevertheless, the high cost of vanadium metal hinders the continued commercialization of vanadium redox flow batteries (VRFBs), prompting the exploration of low-cost all-iron RFBs as a viable alternative. In this context, we propose an innovative deep eutectic-based all-iron hybrid RFBs. By synthesizing a deep eutectic solvent through the mixture of choline chloride, ethylene glycol, and an appropriate amount of deionized water, the deficiencies in mass transport performance of the deep eutectic electrolyte have been successfully addressed, while enhancing its conductivity. The deep eutectic solvents facilitate the restructuring of the solvent shell surrounding the negative electrolyte Fe2+, effectively suppressing its hydrolysis. Additionally, the synergistic interaction between the restructured solvation structure and the chelating ring structure formed between Fe2+ and glycine improves the deposition morphology of iron. Simultaneously, utilizing a eutectic-based positive electrolyte improves the solubility of active substances while maintaining excellent cycling stability and mass transport performance. The entire battery system exhibits an average coulombic efficiency exceeding 98 % in a 360-hour charge–discharge cycle at 10 mA/cm2. In the first 66 cycles, the coulombic efficiency remains at 100 %, and the energy efficiency approaches 54 %. This indicates that the battery system developed using deep eutectic solvents demonstrates promising applications within the same category of eutectic-based batteries.

Oxidative amidation of aldehydes with amine in a mixture of choline chloride and aluminium nitrate as oxidant and solvent

Amides can be synthesized directly from aldehydes and amines in high yield using a catalyst. The reaction, involving aldehydes and amines, was carried out in a mixture containing choline chloride and aluminum nitrate as a solvent and a catalyst to produce amides. Such catalyst was far more effective compared to other current catalytic systems. The reaction consistently gave exceptionally remarkable results for various aldehyde and amine derivatives under the specified reaction conditions. This method offers several advantages, including easy separation of products, efficiency, environmentally safe nature of the solvent, and elimination of expensive and hazardous catalysts. These features emphasize the importance of such groundbreaking reactions. Due to the significant polar characteristics and insolubility of the resulting products in water, the addition of water into the reaction mixture facilitates the easy separation of the products from the reaction medium. Consequently, this particular ionic liquid method provides a simple route for the synthesis of these important compounds.

Combination of Natural Deep Eutectic Solvents and Nano-Liquid Chromatography towards White Analytical Chemistry: A Practical Application

In this work, a green and practical analytical method based on natural deep eutectic solvents (NADES) as extraction agents and nano-liquid chromatography as a separation technique was developed. To demonstrate the applicability of the methodology, alkylphenols and bisphenol A were evaluated as model compounds in olive and sunflower oils as model fatty samples by liquid–liquid microextraction. With this aim, several NADES based on mixtures of choline chloride with glycerol, lactic, ascorbic, and citric acids or glycerol with amino acids were evaluated as potential extraction solvents. In addition, to select the most suitable stationary phase for the separation of this group of contaminants, some stationary phases were tested, including Pinnacle II phenyl, Cogent Bidentate C18™, and XBridge® C18. The last one provided the best performance with an analysis time of 11 min. To solve the problem of the compatibility of hydrophilic NADES with chromatographic systems without harming the solubility of analytes, different aqueous organic mixtures were tested. Methanol/water mixtures were the most suitable as an injection solvent. Finally, following the White Analytical Chemistry principles, different tools were used to evaluate the greenness, the practicality, and applicability of the method based on the Analytical Eco-Scale, the Analytical GREEnness metric approach, and the Blue Applicability Grade Index.

On the role of water in antimony electrodeposition from choline chloride/ethylene glycol/water mixture

Through experimental research and theoretical calculation, it was investigated the effect of water and temperature on the electrodeposition of antimony (Sb) on a platinum (Pt) electrode. The plating solutions were prepared by the addition of 0.05 mol L–1 SbCl3 to the mixtures of choline chloride (ChCl), ethylene glycol (EG) and water (W) in the following molar ratio: 1ChCl:2EG (bath 1), 1ChCl:2EG:0.45 W (bath 2), and 1ChCl:2EG:1.62 W (bath 3). Furthermore, the Sb coatings were electrodeposited at 297 and 338 K. The surface morphologies and crystalline structures of Sb electrodeposits were analysed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. In addition, to understand the interactions of Sb3+ species with the other components of the plating solution, models were created and calculated using density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM). The results of the voltammetric behaviour of Sb3+ species indicated that the reduction potential was shifted towards more positive values with increasing water content on the electrolyte, indicating that the water catalyses the electrochemical reduction of the Sb3+ species. The values of the diffusion coefficients for the Sb3+ species were calculated by applying the Cottrell equation, which increased with the addition of water and temperature increment. The water content and temperature increase affect the surface morphologies of the Sb electrodeposited coatings, which is attributed to the improvement of Sb electrodeposition rate. Moreover, Sb electrodeposited coatings were successfully obtained without adding a complexing agent, indicating that the procedure adopted for the Sb electrodeposition is environmentally friendly. The XRD results revealed the pure phase Sb films. DFT simulations indicated that the Sb-Cl interaction is stronger, which suggests the formation of Sb-Cl complexes. Adding H2O molecules favours the electron affinity of the systems, and QTAIM results suggested that this additive decreased the electron density of Sb3+ ions.

Electrodeposition of copper on glassy carbon and palladium from choline chloride - ethylene glycol deep eutectic solvent

Electrodeposition of copper from deep eutectic solvents (DES) based on a mixture of choline chloride and ethylene glycol containing CuCl2·2H2O at 50 °C and 80 °C was studied. Electrochemical reduction/oxidation of Cu(II)/Cu(0) on glassy carbon (GC) and palladium (Pd) electrodes was investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV) emphasizing that this process takes place through two steps, Cu(II) ↔ Cu(I) and Cu(I) ↔ Cu(0). The CV results showed that in chloride-rich DES electrolytes, the increased presence of chloro ligands raises the overpotential required for Cu electrodeposition. The electrochemical impedance spectroscopy (EIS) results indicate simultaneous electrodeposition of Cu and electrosorption of large cations on electrodeposited Cu on both GC and Pd substrates. Scanning electron microscopy (SEM) results showed that Cu grains of approximately 1 μm were obtained by electrodeposition of Cu on both Pd and GC, whereby better coverage by electrodeposited Cu was obtained on Pd than on GC. Cu electrodeposited on Pd was relatively uniform and smooth, but porous, while Cu electrodeposited on GC was dispersed in small agglomerates. Energy-dispersive X-ray spectroscopy (EDS) of Cu electrodeposited on Pd detected the dominant presence of Cu with the possibility of the formation of CuPd alloy. The presence of CuPd alloy face-centred cubic structures is confirmed by X-ray diffraction (XRD) along with metallic Cu.

Translational and reorientational dynamics in carboxylic acid-based deep eutectic solvents.

The glass formation and the dipolar reorientational motions in deep eutectic solvents (DESs) are frequently overlooked, despite their crucial role in defining the room-temperature physiochemical properties. To understand the effects of these dynamics on the ionic conductivity and their relation to the mechanical properties of the DES, we conducted broadband dielectric and rheological spectroscopy over a wide temperature range on three well-established carboxylic acid-based natural DESs. These are the eutectic mixtures of choline chloride with oxalic acid (oxaline), malonic acid (maline), and phenylacetic acid (phenylaceline). In all three DESs, we observe signs of a glass transition in the temperature dependence of their dipolar reorientational and structural dynamics, as well as varying degrees of motional decoupling between the different observed dynamics. Maline and oxaline display a breaking of the Walden rule near the glass-transition temperature, while the relation between the dc conductivity and dipolar relaxation time in both maline and phenylaceline is best described by a power law. The glass-forming properties of the investigated systems not only govern the orientational dipolar motions and rheological properties, which are of interest from a fundamental point of view, but they also affect the dc conductivity, even at room temperature, which is of high technical relevance.

Electrocatalytic behavior of Ni–Mo alloy electrodeposited from deep eutectic solvents-assisted plating baths: electrochemical impedance spectroscopy study

The electrocatalytic behavior of electrodeposited Ni and Ni–Mo alloy coatings in the hydrogen evolution reaction in a 1 M NaOH aqueous solution was investigated by means of the electrochemical impedance spectroscopy method. The electrochemical deposition of electrocatalytic coatings was carried out using electrolytes based on deep eutectic solvents (eutectic mixtures of choline chloride with ethylene glycol or urea). To simulate the recorded Nyquist plots reflecting the electrocatalytic performance of deposited coatings, a modified Armstrong-Henderson equivalent circuit was employed, which accounts for the involvement of adsorbed intermediates in the reaction. The equivalent circuit included three polarization resistances and three constant phase elements, allowing for the consideration of the localization of the electrochemical process on different surface microdomains. It was found that the electrocatalytic activity of nickel coatings deposited from deep eutectic solvents exceeded the activity of nickel fabricated in an aqueous electrolyte. The increase in molybdenum content in the coating was shown to enhance electrocatalytic activity. It was established that the main reasons for improving the electrocatalytic properties of the Ni–Mo alloy coatings are structural-morphological factors (increase in the degree of microheterogeneity of the surface and the development of the surface area available for electrochemical reaction) and the formation of a favorable electronic structure of the metal, leading to the acceleration of the rate-determining Volmer step.

Anodic surface treatment of nickel in eutectic ionic liquids based on choline chloride for electrochemical polishing and enhancement of electrocatalytic activity in hydrogen evolution reaction

The paper reports the impact of anodic potentiostatic treatment of nickel in two representatives of a new type of eutectic ionic liquids (deep eutectic solvents), ethaline and reline, which are eutectic mixtures of choline chloride with ethylene glycol and urea, respectively. The influence of anodic treatment on surface morphology, roughness coefficients, and electrocatalytic activity towards the hydrogen evolution reaction is characterized. It is demonstrated that the current densities of nickel anodic dissolution in reline are approximately an order of magnitude lower than in ethaline under all other identical conditions. Significant differences in the kinetics of nickel anodic dissolution and passivation during anodic polarization in ethaline and reline have been established, which may be attributed to both a substantial difference in the viscosity of these solvents and differences in the chemical nature and composition of the ions present in them. It is found that anodic treatment in ethaline, at certain potentials, results in electrochemical polishing of the surface, confirmed by a decrease in measured roughness coefficients, while anodic treatment in reline does not allow effective electropolishing and only surface etching (increase in roughness coefficients) is observed. Anodic potentiostatic treatment of nickel in both investigated deep eutectic solvents at specific electrode potential values significantly enhances the electrocatalytic activity of the surface towards the hydrogen evolution reaction in an alkaline environment. This finding can be utilized in the development of electrocatalytic materials for the electrolytic synthesis of green hydrogen.

A comparative study of deep eutectic solvents based on fatty acids and the effect of water on their intermolecular interactions

In this work, intermolecular interactions among the species of fatty acids-based DESs with different hydrogen bond acceptors (HBA) in the adjacent water have been investigated using molecular dynamics (MD) simulation. The results of this work provide deep insights into understanding the water stability of the DESs based on thymol and the eutectic mixtures of choline chloride and fatty acids at a temperature of 353.15 K and atmospheric pressure. Stability, hydrogen bond occupancy analysis, and the distribution of the HBA and HBD around each other were attributed to the alkyl chain length of FAs and the type of HBA. Assessed structural properties include the combined distribution functions (CDFs), the radial distribution functions (RDFs), the angular distribution functions (ADFs), and the Hydrogen bonding network between species and Spatial distribution functions (SDF). The reported results show the remarkable role of the strength of the hydrogen bond between THY molecules and fatty acids on the stability of DES in water. The transport properties of molecules in water–eutectic mixtures were analyzed by using the mean square displacement (MSD) of the centers of mass of the species, self-diffusion coefficients, vector reorientation dynamics (VRD) of bonds and the velocity autocorrelation function (VACF) for the center of the mass of species.

Advancing biomedical substrate engineering: An eco-friendly route for synthesizing micro- and nanotextures on 3D printed Ti–6Al–4V

This study investigates the impact of a combined approach involving sandblasting and electrochemical surface treatment using a deep eutectic solvent Ethaline, a eutectic mixture of choline chloride and ethylene glycol, on the surface characteristics of Ti–6Al–4V biomedical substrates fabricated through direct selective laser melting (DSLM). Research has focused on surface morphology, topography, chemical composition, and cell adhesion. The novel approach demonstrated the ability to create a hierarchical surface structure with both micro and nanopatterns. The rough edges resulting from the sandblasting process were effectively smoothed through subsequent electrochemical processing. Additionally, the issue of residual sand particles, which commonly arise in sandblasting procedures, was successfully addressed with the new method. The results indicated that Ti alloy samples subjected to sandblasting and electrochemical treatment in Ethaline exhibited improved surface hydrophilicity. In-vitro cell adhesion tests confirmed the potential for bio-inspired properties of DSLM-printed Ti–6Al–4V biomedical substrates achieved through the combination of sandblasting and electrochemical processing in Ethaline.

Efficient Molecular Dynamics Simulations of Deep Eutectic Solvents with First-Principles Accuracy Using Machine Learning Interatomic Potentials.

In recent years, deep eutectic solvents emerged as highly tunable and ecofriendly alternatives to common organic solvents and liquid electrolytes. In the present work, the ability of machine learning (ML) interatomic potentials for molecular dynamics (MD) simulations of these liquids is explored, showcasing a trained neural network potential for a 1:2 ratio mixture of choline chloride and urea (reline). Using the ML potentials trained on density functional theory data, MD simulations for large systems of thousands of atoms and nanosecond-long time scales are feasible at a fraction of the computational cost of the target first-principles simulations. The obtained structural and dynamical properties of reline from MD simulations using our machine learning models are in good agreement with the first-principles MD simulations and experimental results. Running a single MD simulation is highlighted as a general shortcoming of typical first-principles studies if the dynamic properties are investigated. Furthermore, velocity cross-correlation functions are employed to study the collective dynamics of the molecular components in reline.

Trace Water Changes Metal Ion Speciation in Deep Eutectic Solvents: Ce3+ Solvation and Nanoscale Water Clustering in Choline Chloride-Urea-Water Mixtures.

Eutectic mixtures of choline chloride, urea, and water in deep eutectic solvent (DES)/water molar hydration ratios (w) of 2, 5, and 10, with dissolved cerium salt, were measured using neutron diffraction with isotopic substitution. Structures were modeled using empirical potential structure refinement (EPSR). Ce3+ was found to form highly charged complexes with a mean coordination number between 7 and 8, with the shell containing mostly chloride, followed by water. The shell composition is strongly affected by the molar ratio of dilution, as opposed to the mass or volume fraction, due to the high affinity of Cl- and H2O ligands that displace less favorable interactions with ligands such as urea and choline. The presence of Ce3+ salt disrupted the bulk DES structure slightly, making it more electrolyte-like. The measured coordination shell of choline showed significant discrepancies from the statistical noninteracting distribution, highlighting the nonideality of the blend. Cluster analysis revealed the trace presence of percolating water clusters (25 ≥ n ≥ 2) in solvent compositions of 5 and 10w for the first time.