Theoretical Study on Ionic Surfactants that Participate in Electrochemical Adsorption Processes

Abstract

Surfactants have been applied in diverse practical situations mostly related to adsorption phenomena. Also, micelles are quite important to electrocatalytic processes, namely in reactions with nonpolar substrates in aqueous environments. The Critical Micellar Concentration (CMC) and Surface Packing Parameter (G) are parameters that facilitate characterization of the micellization process. In this research work, we have calculated through Quantum Mechanics methods (DFT) a group of nine anionic surfactants. Thus, a model has been built of an hemimicelle fragment optimized by means of a semiempirical method AM1, which allowed us to obtain new geometric parameters with the aim to assess G in conditions where the surfactant molecule is not considered in isolation. A multiple lineal regression analysis was used employing the CMC as the dependent variable, to propose a Quantitative Structure- Property Relationship (QSPR)

Quantumchemical Calculations of the Structural Stability of β–Cyclodextrin/Dopamine and β–Cyclodextrin/Ascorbic Acid Systems

“…Hence, at lower pH values the fully protonated DA is obtained, namely H 3 DA + . Conformers of this molecule with minimum energy are the so-called anti, distal and proximal H 3 DA + molecules which are reported elsewhere [20]. These structures were obtained by varying the dihedral angles Ω 1 and Ω 2 , see Figure 1 ECS Transactions, 47 (1) 53-67 (2013)…”

“…Calculated relative energy and standard Gibbs free energy values (∆E and ∆G o ) for the different conformers of H 3 DA + and its accordingly dihedral angle. The literature reported data[20] are shown for comparison.…”