(197bh) Study of Adsorption Behavior of Surfactant Micelles on Surfactant Covered Iron Surfaces Via Molecular Simulation
AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
Computational Molecular Science and Engineering Forum
Poster Session: Computational Molecular Science and Engineering Forum
Monday, November 6, 2023 - 3:30pm to 5:00pm
Surfactant â metal interactions are important in applications like corrosion inhibition and synthesis of metallic nanoparticles, wherein surfactants are often added above their critical micelle concentration. Under these conditions, surfactant micelles exist in dynamic equilibrium with free surfactant molecules. Due to their faster diffusion compared to the micelles, free surfactant molecules rapidly adsorb onto metal-water interfaces. Therefore, adsorbing surfactant micelles invariably encounter metal-water inter-faces with some adsorbed surfactants. We have studied, via atomistic simulations, adsorption behavior of micelles of a quaternary ammonium-based surfactant at iron-water interfaces that are partially or fully covered with adsorbed surfactant molecules. We find that on a partially covered surface, a micelle prefers to adsorb on a bare metal patch. On a fully covered surface, the micelle adsorbs on top of already adsorbed molecules and attains a hemispherical morphology. The adsorption free energy decreases as the coverage of iron-water interface with surfactants increases.