Micellar Cubic Phases and Their Structural Relationships:  The Nonionic Surfactant System C₁₂EO₁₂/Water

Abstract

We present the binary phase diagram of the system dodecaoxyethylene mono-n-dodecyl ether (C12EO12)/water, which is the first pure surfactant system found to exhibit three different type I (oil-in-water) micellar cubic phases. As hydration increases the hexagonal, HI, phase transforms into a cubic, I1, phase of space group Pm3n, which, on further hydration, forms a second micellar cubic phase of space group Im3m (phase designated as Im3m). In addition, a third micellar cubic phase, of space group Fm3m, forms at low temperature and high hydration, adjacent to the L1 micellar solution. We have succeeded in growing monodomains of the hexagonal, and some of these cubic phases and have thereby investigated the epitaxial relationships between the phases. The results suggest an “undulating cylinder” mechanism for the Im3m−HI transition.

Sphericity and symmetry breaking in the formation of Frank–Kasper phases from one component materials

“…The scientific literature is replete with examples of Frank-Kasper phases in hard materials, particularly in the area of intermetallics (7)(8)(9), but also in a few complex elemental crystals, including manganese (10,11) and uranium (12). Recently, this class of crystalline order has cropped up in a host of soft materials, including dendrimers (13), surfactant solutions (14), and block polymers (15,16), often in close proximity to QC phases (17)(18)(19). To the best of our knowledge the principles underlying the formation of Frank-Kasper phases across both categories of materials have not been established, presenting enticing challenges to scientist and engineers bent on controllably arranging atoms and molecules for specific materials applications.…”

Kinetics of hexagonal cylinders to face-centered cubic spheres transition of triblock copolymer in selective solvent: Brownian dynamics simulation

“…[37][38][39] Addition of selective low molecular weight solvent or homopolymer to the block copolymer gives rise to additional phase behaviors on the system. A stable FCC phase of spherical micelles has been reported in block copolymer solution systems [40][41][42][43][44][45][46][47] as well as in block copolymer/ homopolymer blends. 46 McConnell et al 40 studied poly(styrene-b-isoprene) (SI) in decane, a selective solvent to PI, and observed the FCC and BCC spheres phase.…”

The role of charged surfactants in the thermal and structural properties of lyotropic liquid crystalline mesophases of [Zn(H2O)6](NO3)2?CnEOm?H2O

“…Fig. 2A 2 , water, and charged surfactants (see later). The XRD patterns can be indexed to (1 0 0), (2 0 0), and (3 0 0) lines.…”

“…The lyotropic liquid crystalline mesophase (LLCM) of oligo(ethylene oxide), C n H 2n+1 (OCH 2 CH 2 ) m OH (represented as C n EO m ) type surfactants with water [1][2][3] and water-oil [4,5] have been well established over the years. The water-C n EO m LLCM can accommodate transition metal salt (TMS) without disturbing the mesophase, denoted as TMS-water-C n EO m mesophase [6][7][8][9][10].…”