softmatter:Hexagonally Packed Cylindrical Micelles

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Isosurface images of hexagonally packed cylinders formed from a BCP system.

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 ~0.15-0.3 or ~0.7-0.85, have been shown to form cylindrical micelles that order into hexagonal arrangements [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 hexagonally packed cylindrical micelles for volume fractions of approximately 0.2 - 0.3 [2]. Simulations of assymetric surfactants have also yielded hexagonally packed cylinders for volume fractions of ~0.45, see the full MATDL record for more info [2].

Tethered Particles

Tether-aggregating tethered nanospheres (TNS) were found to exhibit hexagonally packed cylindrical micelles for a range of volume fractions and various Excluded volume ratio values (ratio of the nanoparticle to tether) [2]. An example can be viewed MATDL repository.

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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