Related Experiment Video
Updated: Feb 19, 2026
Extraction and Characterization of Surfactants from Atmospheric Aerosols
Published on: April 21, 2017
The Driving Force for the Association of Gemini Surfactants
Kyeong-Jun Jeong1, Arun Yethiraj1
1Theoretical Chemistry Institute and Department of Chemistry , University of Wisconsin , Madison , Wisconsin 53706 , United States.
Abstract:
The self-assembly of surfactants into lyotropic liquid crystalline phases is interesting from a fundamental and practical perspective. The propensity for self-assembly is particularly interesting in Gemini surfactants which have a very low critical micelle concentration. In this work, we study the effect of headgroup identity on the driving force for the self-assembly of Gemini surfactants, using computer simulations of the potential of mean force (PMF). We find that surfactants with sulfonate headgroups have a greater tendency to assemble than those with carboxylate headgroups. The minimum in the PMF is about a factor of 2 deeper and occurs at shorter distances. Interestingly, the driving force is entropic with the carobxylate and energetic with the sulfonate headgroups. Analysis of different contributions suggests that these differences arise from surfactant headgroup electrostatics and size. The results provide an explanation for why the morphology diagram of the sulfonate surfactants is insensitive to temperature.
Related Concept Videos
03:13Intermolecular Forces
01:24Van der Waals Interactions
02:56Intermolecular Forces and Physical Properties
02:57Surface Tension, Capillary Action, and Viscosity
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
02:34Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
02:28Intermolecular Forces in Solutions
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...