softmatter:Cubically Ordered Spherical Micelles

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Block Copolymers (BCPs) and Surfactants are known to phase separate into complex morphologies including Cubically Ordered Spherical Micelles, Hexagonally Packed Cylindrical Micelles, Double Gyroid, Perforated Lamella, and Lamella. Recent simulation results have shown that Tethered building blocks also can exhibit similar phases as a result of microphase separation.

Contents

Block Copolymers

Melts of assymmetric BCPs, with block fractions of ~0.1 or ~0.9, have been shown to form spherical micelles that order into Body Centered Cubic (BCC) arrangements, as well as close-packed spherical micelles as assymmetry is increased [1]. Here block fraction is defined as (length of the A block)/(total length of polymer).

Surfactants

Simulations of symmetric Surfactants in selective solvent have also yielded BCC ordered spherical micelles for volume fractions of approximately 0.1 - 0.2 [2].

Tethered Nanospheres

Tether-aggregating tethered nanospheres (TNS) were found to exhibit Hexagonally Close Packed (HCP) spherical micelles for volume fractions ~0.2-0.3, where the excluded volume ratio of head to tail Fv = 1.95 [2].

References

  • [1] Matsen and Bates, Macromolecules 29:1091, 1996
  • [2] Iacovella CR, Horsch MA, Zhang Z, Glotzer SC, Phase diagrams of self-assembled mono-tethered nanospheres from molecular simulation and comparison to surfactants, LANGMUIR 21 (21): 9488-9494 OCT 11 2005
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