Self-assembling and phase coexistence of SW trimers as complex amphiphile analogues. I. Simulations

Abstract

We analyse by discrete molecular dynamics the self-assembly of SW trimer particles that contain a different number of attractive and repulsive spheres. They also have different geometries: linear, obtuse, rectangular and equilateral. We identify that some of these molecules exhibit liquid–vapour equilibria while others do not. For all of them, we show the morphological phase diagram built up from the different supra-molecular structures formed by each type of trimer. We simulated 14 different systems with a total of 321 states. The main features of the supra-molecular structures depend only on the composition and geometry of the trimer: triple SW trimers do not form supra-structures, double SW trimers and single SW trimers form monolayers, bilayers and worm-like micelles. The liquid–vapour coexistence properties are also exhibited. These trimers can be used to model complex amphiphiles beyond the standard ones, such as the Gemini and the Bola surfactants as well as colloidal particles.

GRAPHICAL ABSTRACT

Keywords:

• Self-assembly
• square well trimers
• morphological phase diagrams
• supra-molecular structures
• monolayers

Acknowledgments

We thank the Laboratorio Nacional de Cómputo de Alto Desempeño, LANCAD, Mexico, for computing support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

We acknowledge support for this work from project FDC 2015-02-1450 of Consejo Nacional de Ciencia y Tecnología (Conacyt), México.