Understanding the adsorption of ionic liquids onto zeolite ZSM-5 from aqueous solution: experimental and computational modelling

Confined ionic liquids films under shear: The importance of the chemical nature of the solid surface

Ionic liquids have generated interest in applications as lubricants and as additives to conventional lubricants due to their unique physical properties. In these applications, the liquid thin film can be subjected simultaneously to extremely high shear and loads in addition to nanoconfinement effects. Here, we use molecular dynamics simulations with a coarse-grained model to study a nanometric film of an ionic liquid confined between two planar solid surfaces both at equilibrium and at several shear rates. The strength of the interaction between the solid surface and the ions was changed by simulating three different surfaces with enhanced interactions with different ions. The increase in the interaction with either the cation or the anion leads to the formation of a solid-like layer that moves alongside the substrates; however, this layer can exhibit different structures and stability. An increase in the interaction with the high symmetry anion produces a more regular structure that is more resistant to the effects of shear and viscous heating. Two definitions were proposed and used for the calculation of the viscosity: a local definition based on the microscopic characteristics of the liquid and an engineering definition based on the forces measured at the solid surfaces, with the former displaying a correlation with the layered structure induced by the surfaces. Because of the shear thinning behavior of the ionic liquids as well as the temperature rise brought on by viscous heating, both the engineering and the local viscosities decrease as the shear rate increases.

Ionic liquid [bmim] [TFSI] templated Na-X zeolite for the adsorption of (Cd2+, Zn2+), and dyes (AR, R6)

1-butyl-3-methylimidazolium bis(triflouromethylsufonyl)imide functionalization to Na-X zeolite (IFZ) is the primary goal of this study in order to evaluate its ability to remove heavy metals (Cd²⁺), (Zn²⁺), dyes Rhodamine 6G (R6), and Alizarin Red S (AR) from aqueous streams. IFZ was thoroughly examined using analytical techniques XRD, BET, FE-SEM, and FTIR, to better understand its physical and chemical properties. The surface area and the volume of pores (IFZ; 19.93 m²/g, 0.0544 cm³/g) were reduced in comparison to the parent zeolite (Na-X; 63.92 m²/g, 0.0884 cm³/g). According to SEM, the crystal structure of the zeolite (Na-X) has not been significantly altered by XRD analysis. The mechanism, kinetics, isotherms, and thermodynamic properties of adsorption were all studied using batch adsorption experiments under various operating conditions. IFZ adsorbs dyes (AR; 76.33 mg/g, R6; 65.85 mg/g) better than metal ions (Cd²⁺; 30.68 mg/g, Zn²⁺; 41.53 mg/g) in acidic conditions. The Langmuir isotherm and pseudo-second order models were found to be the most accurate models for equilibrium data. Adsorption is endothermic and spontaneous, as revealed by the thermodynamics of the process. The IFZ can be used in three (Cd²⁺), two (Zn²⁺), four (AR), and five (R6) cycles of desorption and regeneration. For these reasons, IL-modified zeolite can be used to remove multiple types of pollutants from water in one simple step.

A comprehensive study on the impact of chemical structures of ionic liquids on the solubility of ethane

The solubility of ethane is not only governed by the electrostatic–misfit of the solute toward ionic liquids, but also the existence of a preferential site for ethane to interact with the ionic liquid's non-polar moiety.