Theoretical Study on Amino Acid-Based Ionic Pairs and Their Interaction with Carbon Nanostructures

Quantum chemistry methods were used to analyze the properties of ionic pairs formed by combination of the 1-ethyl-3-methylimidazolium cation with anions derived from alanine, glycine, serine, and phenylalanine amino acids, which appear in the corresponding ionic liquids. Anion–cation pairs were studied from structural and energetic viewpoints using density functional theory together with the use of natural bond orbital and atoms in a molecule approaches. Interactions of the mentioned ionic pairs with carbon nanostructures carried out with graphene sheets and single-walled carbon nanotubes, with ions placed on the outer surface and when confined inside the nanotube, were analyzed from first principles. Interaction energies, density of states, and charge density allow inferring the mechanism of interaction between the ion pairs and graphene or carbon nanotubes

Theoretical Study of Amino Acid-Based Ionic Liquids Interacting with Carbon Nanosystems

The properties of 1-ethyl-3-methylimidazolium glycinate ionic liquid regarding fullerenes, graphene, and single-walled carbon nanotubes are studied using classical molecular dynamics simulations. Endohedral fullerenes forming C60 to C540 containing a variable number of confined ions are studied, and the solvation of these systems by bulk liquid phases is also studied. The adsorption of the ionic liquid on top of graphene sheets and the confinement between two sheets are also analyzed as a function of intersheet separation. Likewise, confinement inside single-walled nanotubes as a function of nanotube diameter is analyzed together with ionic mobility in comparison with bulk phases. External solvation, densification, and layering around the nanotubes are also considered. The properties of these systems involving amino acid-based ionic liquids are compared with available studies involving classical imidazolium ionic liquids with other types of ions

Proportion of Patients Classified by the MDR-TB Score and Likelihood Ratios.

<p>MDR-TB: Multidrug-resistant tuberculosis, CI: confidence interval.</p

Study Population Characteristics.

<p>*Data is expressed as n (%) or mean ± SD.</p>†<p>Failed therapy or early relapse within 12 months.</p

Multidrug-Resistance Pulmonary Tuberculosis (MDR-TB) Score.

<p>BCa  =  Bias-Corrected and accelerated, CI: confidence interval.</p><p>*Failed therapy or early relapse within 12 months.</p