From faceted vesicles to liquid icoshedra: Where topology and crystallography meet

Journal Article · Wed Feb 17 00:00:00 EST 2016 · Current Opinion in Colloid & Interface Science

DOI:https://doi.org/10.1016/j.cocis.2016.02.002· OSTI ID:1340353

Guttman, Shani ^[1]; Ocko, Benjamin M. ^[2]; Deutsch, Moshe ^[3]; Sloutskin, Eli ^[3]

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1. Bar-Ilan University (Israel). Physics Department and Institute of Nanotechnology & Advanced Materials
2. Brookhaven National Lab. (BNL), Upton, NY (United States). NSLS-II
3. Physics Department and Institute of Nanotechnology & Advanced Materials

We study many common amphiphiles that spontaneously self-assemble in aqueous solutions, forming membranes and unilamellar vesicles. While the vesicular membranes are bilayers, with the hydrophilic moieties exposed to the solution, the structure formed by amphiphiles at the oil–water (i.e., alkane–water) interfaces, such as the surface of an oil droplet in water, is typically a monolayer. It has recently been demonstrated that these monolayers and bilayers may crystallize on cooling, with the thermodynamic conditions for this transition set by the geometry of the constituent molecules. While a planar hexagonal packing motif is particularly abundant in these crystals, a hexagonal lattice is incompatible with a closed-surface topology, such as a closed vesicle or the surface of a droplet. Thus, (at least) 12 five-fold defects form, giving rise to a complex interplay between the stretching and the bending energies of these two-dimensional crystals; in addition, a central role is also played by the interfacial tension. This interplay, part of which has been theoretically studied in the past, gives rise to a range of unexpected and counterintuitive phenomena, such as the recently-observed temperature-tunable formation of stable liquid polyhedra, and a tail growing and droplet-splitting akin to the spontaneous emulsification effect.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC00112704; SC0012704
• OSTI ID: 1340353
• Alternate ID(s): OSTI ID: 1352285
• Report Number(s): BNL-112073-2016-JA
• Journal Information: Current Opinion in Colloid & Interface Science, Vol. 22, Issue C; ISSN 1359-0294
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Emulsion
Topological defect
Spontaneous emulsification
Alkane
Surfactant