Affiliations 

  • 1 Department of Chemical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ, United Kingdom
  • 2 Specialty Chemical Technology, PETRONAS Research Sdn Bhd, Malaysia
  • 3 Departamento de Ingenieria Quimica, Universidad de Concepcion, Concepcion, Chile
  • 4 Department of Chemical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ, United Kingdom. Electronic address: e.muller@imperial.ac.uk
J Colloid Interface Sci, 2024 Jul 08;674:1071-1082.
PMID: 39013277 DOI: 10.1016/j.jcis.2024.07.002

Abstract

Hypothesis Atomistically-detailed models of surfactants provide quantitative information on the molecular interactions and spatial distributions at fluid interfaces. Hence, it should be possible to extract from this information, macroscopical thermophysical properties such as interfacial tension, critical micelle concentrations and the relationship between these properties and the bulk fluid surfactant concentrations. Simulations and Experiments Molecular-scale interfacial of systems containing n-dodecyl β-glucoside (APG12) are simulated using classical molecular dynamics. The bulk phases and the corresponding interfacial regions are all explicitly detailed using an all-atom force field (PCFF+). During the simulation, the behaviour of the interface is analyzed geometrically to obtain an approximated value of the critical micelle concentration (CMC) in terms of the surfactant area number density and the interfacial tension is assessed through the analysis of the forces amongst molecules. New experimental determinations are reported for the surface tension of APG12 at the water/air and at the water/n-decane interfaces. Findings We showcase the application of a thermodynamic framework that inter-relates interfacial tensions, surface densities, CMCs and bulk surfactant concentrations, which allows the in silico quantitative prediction of interfacial tension isotherms.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.