Self-assembly of ionic surfactants and formation of mesostructures

    Authors

    A. Bhattacharya;S. D. Mahanti

    Abbreviated Journal Title

    J. Phys.-Condes. Matter

    Keywords

    MESOPOROUS MOLECULAR-SIEVES; INORGANIC-ORGANIC INTERFACES; MICELLE; FORMATION; LATTICE MODEL; SIMULATIONS; SILICA; TEMPLATES; PHASE; SIZE; Physics, Condensed Matter

    Abstract

    Self-assembly of ionic surfactants resulting in micelle formation is studied using off-lattice Monte Carlo simulation in two dimensions (2D). We find that in addition to the Lennard-Jones (LJ) interaction, which acts among all of the particles, a screened Coulomb interaction, acting only among the surfactant heads, makes the geometric arrangement of micelles very different compared to that for neutral surfactants at the same density. At low concentrations, ionic surfactants produce spherical micelles and exhibit intermicellar ordering arising out of the longer-range repulsion of the surfactant head groups. For larger concentrations, they tend to form bi-layers. Motivated by recent experiments on preparation of mesoporous sieves through surfactant-templating routes, we then extend these studies to micellization of ionic surfactants in the presence of other neutral host particles. The morphologies of the surfactant-host composites are studied as functions of host particle densities, sizes, and their interaction strengths. Assuming the presence of micelles as quenched disorder, we obtain a qualitative understanding of the local ordering of the host particles in terms of a dimensionless density parameter from the known liquid-vapour phase diagram in 2D of a LJ fluid.

    Journal Title

    Journal of Physics-Condensed Matter

    Volume

    13

    Issue/Number

    7

    Publication Date

    1-1-2001

    Document Type

    Article

    Language

    English

    First Page

    1413

    Last Page

    1428

    WOS Identifier

    WOS:000167308400008

    ISSN

    0953-8984

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