Deep eutectic solvent formation: a structural view using molecular dynamics simulations with classical force fields

The effects of a hydrogen bond acceptor and hydrogen bond donor on carbon dioxide absorption via natural deep eutectic solvents were studied in this work. Naturally occurring non-toxic deep eutectic solvent constituents were considered; choline chloride, b-alanine, and betaine were selected as hydrogen bond acceptors; lactic acid, malic acid, and fructose were selected as hydrogen bond donors. Experimental gas absorption data were collected via experimental methods that uses gravimetric principles. Carbon dioxide capture data for an isolated hydrogen bond donor and hydrogen bond acceptor, as well as natural deep eutectic solvents, were collected. In addition to experimental data, a theoretical study using Density Functional Theory was carried out to analyze the properties of these fluids from the nanoscopic viewpoint and their relationship with the macroscopic behavior of the system, and its ability for carbon dioxide absorption. The combined experimental and theoretical reported approach work leads to valuable discussions on what is the effect of each hydrogen bond donor or acceptor, as well as how they influence the strength and stability of the carbon dioxide absorption in deep eutectic solvents. Theoretical calculations explained the experimental findings, and combined results showed the superiority of the hydrogen bond acceptor role in the gas absorption process, with deep eutectic solvents. Specifically, the cases in which choline chloride was used as hydrogen bond acceptor showed the highest absorption performance. Furthermore, it was observed that when malic acid was used as a hydrogen bond donor, it led to low carbon dioxide solubility performance in comparison to other studied deep eutectic solvents. The cases in which lactic acid was used as a hydrogen bond donor showed great absorption performance. In light of this work, more targeted, specific, deep eutectic solvents can be designed for effective and alternative carbon dioxide capture and management.

Insight into the structural and transport properties of methyl and benzyl triphenyl phosphonium based deep eutectic solvents using molecular dynamics simulations

Partitioning behavior of rutin in novel liquid–liquid biphasic systems formed by choline chloride/ maltose natural deep eutectic solvents and n-propanol

Molecular dynamics study on the use of Deep Eutectic Solvents for Enhanced Oil Recovery

Investigating the effect of systematically modifying the molar ratio of hydrogen bond donor and acceptor on solvation characteristics of deep eutectic solvents formed using choline chloride salt and polyalcohols

Article Crystal structure of 2,2′-biimidazolium bis(dihydrogen phosphate), [C6H8N4][H2PO4]2 was published on March 1, 2010 in the journal Zeitschrift für Kristallographie - New Crystal Structures (volume 225, issue 1).

Thermo-rheological characterization of Malic Acid based Natural Deep Eutectic Solvents

COSMO-RS predictive screening of type 5 hydrophobic deep eutectic solvents for selective platform chemicals absorption

Naringenin (NA) is a natural flavonoid used in the formulation of a wide range of pharmaceutical, fragrance, and cosmetic products. In this research, NA was extracted from Searsia tripartita using an environmentally friendly, high efficiency extraction method: an ultrasound-assisted extraction with deep eutectic solvents (UAE-DES). Six natural deep eutectic solvent systems were tested. Choline chloride was used as the hydrogen bond acceptor (HBA), and formic acid, ethylene glycol, lactic acid, urea, glycerol, and citric acid were used as hydrogen bond donors (HBD). Based on the results of single-factor experiments, response surface methodology using a Box-Behnken design was applied to determine the optimal conditions for UAE-DES. According to the results, the optimal NA extraction parameters were as follows: DES-1 consisted of choline chloride (HBA) and formic acid (HBD) in a mole ratio of 2:1, an extraction time of 10 min, an extraction temperature of 50°C, an ultrasonic amplitude of 75 W, and a solid-liquid ratio of 1/60 g/mL. Extracted NA was shown to inhibit the activity of different enzymes in vitro, including α-amylase, acetylcholinesterase, butyrylcholinesterase, tyrosinase, elastase, collagenase, and hyaluronidase. Thus, the UAE-DES technique produced high-efficiency NA extraction while retaining bioactivity, implying broad application potential, and making it worthy of consideration as a high-throughput green extraction method.

Water based-deep eutectic solvent for ultrasound-assisted liquid–liquid microextraction of parabens in edible oil

The effect of water on the physicochemical properties of deep eutectic solvents (DES) is a trending research topic. In this work, inelastic neutron scattering (INS) spectroscopy, was used to probe intermolecular interactions in the water-deep eutectic solvent mixtures for the cases of choline chloride (the hydrogen bond acceptor) and three different hydrogen bond donors, with different degrees of acidity: urea, glycerol and lactic acid. It was found that quenching samples in liquid nitrogen is a procedure that may retain the liquid phase morphology of DES at the low temperatures required by INS spectroscopy. The three studied systems share the preference of water molecules to bind to chloride anion, as predicted by numerous molecular dynamics simulations. Despite this similarity, the three systems present several distinct INS features upon water addition that are related to their unique properties and structure at the molecular level. In the choline chloride:urea system, water molecules promote a strengthening of hydrogen bonds with the NH and OH donors, while for the choline chloride:lactic acid system INS probed the existence of solvated DES clusters instead of specifically interfering water molecules. This study takes advantage from the unique capabilities of INS and paves the way for future studies in these systems.

In situ formation of deep eutectic solvents based dispersive liquid–liquid microextraction for the enrichment of trace phthalate esters in aqueous samples

In-situ formation of deep eutectic solvent based dispersive liquid-liquid microextraction for the extraction of Cr(VI) from water samples before its determination by UV-Vis spectrophotometry

Study of the pseudo-ternary aqueous two-phase systems of deep eutectic solvent (choline chloride:sugars) + K2HPO4 + water

The focus of the investigation is physicochemical properties (electrical conductivity, electrochemical window) and theoretical study of stability of the formed deep eutectic solvents (DESs). Quantum-chemical calculations have been performed to predict the formation of solvents with higher stability. The reported results reveal a complete description of fluid’s characteristics which of the components is the most effective donor for creation hydrogen bond with hydrogen bond acceptor. Two DESs have been synthesized by using of choline chloride as hydrogen bond acceptors (HBAs) and Urea and Lactic acid as hydrogen bond donors (HBDs). Also, DES have been synthesized by using of Lactic acid as hydrogen bond acceptors (HBAs) and Sodium Acetate as hydrogen bond donors (HBDs). The electrical conductivity of deep eutectic solvents was measured and the width of electrochemical window was evaluated using cycling voltammetry depending on water content in the solvent (0–25%).