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.

Effect of water addition on caprylic acid: Quaternary ammonium salts (QAS) deep eutectic solvents: Characterization of their structural and dynamical properties.

Physicochemical properties of the binary mixtures based on Caprylic acid: Quaternary ammonium salts (QAS) (7:3 mol ratio) are investigated using MD simulations. Considering the hydrophobic character of eutectic solvents based on long-chain fatty acids, the stability of the binary mixtures was investigated in the adjacent water. In order to investigate the effect of water on intermolecular interactions in binary mixtures, the structural properties of the binary mixtures in the pure state and adjacent to water were investigated at 310 K. 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 HBA and HBD and Spatial distribution functions (SDF). We aimed to represent the structural stability of eutectic solvents based on Caprylic acid and Quaternary ammonium salts (QAS) as a function of the alkyl chain length of cations, the evidence was found for the interaction between the chloride anion leads to the transition of HBA to the water-rich phase. The alkyl chain length of cations of Quaternary ammonium salts shows the stability of eutectic solvents in the adjacent water.

Investigation the effect of water addition on intermolecular interactions of fatty acids-based deep eutectic solvents by molecular dynamics simulations.

In this work, we focused on the interaction between hydrogen bond acceptor (HBA) and hydrogen bond doner (HBD) in the binary mixtures. The results showed that Cl- anion plays a key role in the formation of DESs. Also, the structural stability of deep eutectic solvents based on fatty acids (FAs) and choline chloride (Ch+Cl-) at different ratios was investigated in water using molecular dynamics simulations. We observed that the interaction between the chloride anion and the hydroxyl group of the cation leads to the transition of HBA to the water-rich phase. These atomic sites have important rule in the stability of the eutectic mixtures based on FAs and Cl- anion. However, it seems that the binary mixtures with the mole percent at 30% of [Ch+Cl-] and 70% of FAs have more stability than other ratios.

Structure and dynamics of hydrophobic deep eutectic solvents composed from terpene-fatty acids investigated by molecular dynamics simulation.

Hydrophobic deep eutectic solvents (HDES) composed of Terpenes and Fatty acids have recently been the subject of great interest for removing pollutants from an aqueous environment. Despite the specific application of Hydrophobic DES and the important role of molecular dynamics simulation in predicting the properties of these compounds, not many studies have been done on their intermolecular interaction. In this work, we performed molecular dynamics simulations for the eutectic mixture based on monoterpene (Menthol, Thymol) and Fatty acids such as Caprylic Acid, Decanoic Acid, Lauric Acid, and Myristic acid. Binary mixtures of Terpene and Fatty acids were prepared at molar ratios 1:1, and their properties were investigated at 323 K. We have carried out 50 ns in the ensemble NPT to understand thermo-physical properties that are largely dependent on the interaction between molecules. Here, the structural properties of the binary mixtures were evaluated, and the possible explanations for their thermo-physical properties have been presented. The interaction between Terpenes and Fatty acids was studied by the structural properties such as the atom-atom radial distribution functions (RDF) and the Hydrogen bonding network between species and Spatial distribution functions (SDF). The structural properties studies revealed that the interaction between Terpenes and Fatty acids decreased the reduction of the accumulation of Terpene molecules around each other in the binary mixtures. Evidence has been acquired that the interaction between the menthol molecules was mostly affected by the Fatty acids molecules. Also, the transport properties of the binary mixtures were explored using the mean-square displacement (MSD) for the centers of mass of molecules, self-diffusion of species, and vector reorientation dynamics (VRD) of bonds. The simulation results indicated that intermolecular interactions play an important role in the dynamic properties of species, and maintains the low melting point of the mixture.

Structural and dynamic properties of eutectic mixtures based on menthol and fatty acids derived from coconut oil: a MD simulation study.

The structural and dynamical properties of the binary mixture of Menthol (MEN) and Fatty acids (FAs) were investigated using molecular dynamics simulations. To this end, the relationship between the structural and dynamical properties of the eutectic mixtures of MEN and FAs with different molar percentages of FAs are studied. Structural properties of the eutectic mixtures were characterized by calculating the combined distribution functions (CDFs), radial distribution functions (RDFs), angular distribution functions (ADFs), hydrogen bonding networks, and spatial distribution functions (SDF). Additionally, our Results indicated robust interactions between menthol and Caprylic acid molecules Finally, the transport properties of the mixtures were investigated using the mean square displacement (MSD) of the centers of mass of the species, self-diffusion coefficients and vector reorientation dynamics (VRD) of bonds. Overall, our simulation results indicated that intermolecular interactions have a significant effect on the dynamic properties of species.