Aligned Nanostructured Polymers by Magnetic-Field-Directed Self-Assembly of a Polymerizable Lyotropic Mesophase

Abstract

Magnetic-field-directed assembly of lyotropic surfactant mesophases provides a scalable approach for the fabrication of aligned nanoporous polymers by templated polymerization. We develop and characterize a lyotropic liquid crystalline system containing hexagonally packed cylindrical micelles of a polymerizable surfactant in a polymerizable solvent. The system exhibits negative magnetic anisotropy, resulting in the degenerate alignment of cylindrical micelles perpendicular to the magnetic field. Sample rotation during field alignment is used to effectively break this degeneracy and enable the production of uniformly well-aligned mesophases. High-fidelity retentions of the hexagonal structure and alignment were successfully achieved in polymer films produced upon UV exposure of the reactive system. The success of this effort provides a route for the fabrication of aligned nanoporous membranes suitable for highly selective separations, sensing, and templated nanomaterial synthesis.

Characterization of the phase behaviour of a novel polymerizable lyotropic ionic liquid crystal

“…[1][2][3][4][5] Lyotropic liquid crystalline phases are formed by the spontaneous self-assembly of amphiphilic molecules with the addition of a co-solvent, typically water, alcohol or glycerol. [1][2][3][4][5] Lyotropic liquid crystalline phases are formed by the spontaneous self-assembly of amphiphilic molecules with the addition of a co-solvent, typically water, alcohol or glycerol.…”

“…[6][7][8][9][10] A wide variety of mesophases exist including lamellar, hexagonal (normal & inverted), discontinuous cubic (Im3m, Fm3m, Pm3n, Fd3m) and bicontinuous cubic (Im3n, Pn3m, Ia3d). 2,15 Among the large diversity of LLC molecules already reported in the literature, one of the most important classes is charged surfactants. discontinuous cubic phase) or anisotropic transport properties (i.e.…”

“…19,[21][22][23][24] A major drawback in the use of LLCs for the design of welldefined nanostructured systems for targeted material applications, such as membrane separation, is the poor mechanical properties of the LLC, which is strongly related to the nanostructure stability and orientation. 2,25,31,32 More recently, a lot of attention in the area of LLC design and characterization has focused on the conception of LLCs with polymerizable moieties. 25 Additionally, the mesophases formed by these LLC systems are extremely sensitive to the co-solvent concentrations as well as temperature, making these materials again not sustainable for many applications where extreme conditions are used.…”

Design of Introspective Circuits for Analysis of Cell-Level Dis-orientation in Self-Assembled Cellular Systems

“…Alternatively, ferrous coatings on certain faces could help orient the blocks in the presence of a strong magnetic field, applied along one axis of the intended assembly (Tousley et al, 2014). Some work has been done using chemically directed self-assembly (Diehl et al, 2002).…”

Exploitation of Self‐Assembly Phenomena in Liquid‐Crystalline Polymer Phases for Obtaining Multifunctional Materials

“…Recently, Tousley et al succeeded in developing a lyotropic LC system containing hexagonally packed cylindrical micelles of commercially available, polymerizable, poly(oxyethylene alkyl phenyl ether) surfactants (namely, Hitenol BC-05 and Noigen RN-10), in combination with a photocurable mixture of butyl acrylate, butanediol diacrylate, and water [36]. The system showed negative magnetic anisotropy, hence promoting the degenerate alignment of the cylindrical micelles perpendicular to the applied external magnetic field.…”