Phase Behavior of an Amphiphilic Molecule in the Presence of Two Solvents by Dissipative Particle Dynamics
Resource
Polymer 48: 877-886
Journal
Polymer
Journal Volume
48
Journal Issue
3
Pages
877-886
Date Issued
2007
Date
2007
Author(s)
Abstract
We examine the phase behavior of AmBn amphiphilic molecules in the presence of two solvents X2 and Y2, which are strongly selective for A and B, respectively, by dissipative particle dynamics (DPD). We find that increasing the immiscibility parameter between the two solvents not only drives a macrophase separation into two phases X2-rich and Y2-rich for systems at less concentrated regimes, but also expands the ordered microphase region at more concentrated regimes. It even induces a sequential transition of various ordered structures. This is not surprising since increasing the solvent immiscibility parameter enhances the preferentiality of X2 for A and Y2 for B, and thus qualitatively varies the degree of molecular asymmetry in the amphiphilic molecules. In general, our current results reveal that the DPD simulation method has successfully captured the phase separation behavior of an amphiphilic molecule in the presence of two solvents. However, we find that the packing order of the spherical micelles is greatly affected by the finite size of the simulation box. As such, it becomes difficult to examine the most stable packing array of spheres via the DPD method. Still, DPD reveals a possible spherical order of A15, which has been observed in some amphiphilic molecule systems. © 2007 Elsevier Ltd. All rights reserved.
Subjects
Amphiphilic; Dissipative particle dynamics; Solvent immiscibility
Other Subjects
Computer simulation; Micelles; Phase separation; Solubility; Solvents; Amphiphilic; Dissipative particle dynamics (DPD); Molecular asymmetry; Solvent immiscibility; Molecular structure; dynamics; phase separation; simulation; solvent
Type
journal article
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