Designing the topology of ion nano-channels in the mesophases of amphiphilic wedge-shaped molecules

Abstract

The wedge-shaped amphiphiles bearing sulfonate groups at the tip of the wedge are prone to form ion nano-channels upon exposure to a humid atmosphere. During swelling, water molecules preferentially accumulate in polar regions of the system resulting in the formation of a lyotropic phase. In this work, the details of the structure formation processes occurring upon swelling in water vapour, including determination of the size and topology of the ion nano-channels, are explored. The electron density profiles across the channel are obtained from the fits of the X-ray scattering data with two- and three-phase structural models the applicability of which is critically analysed. The results show that the ion channel size correlates not only with water uptake but also with the molecular architecture such as the structure of the rigid molecular fragment bearing a polar group. These findings can help optimising the ion transport for development of ion-selective membranes.

Creation and study of organic zeolite-like materials

“…Эти фазы представляют собой органические цеолиты. Их главное преимущество заключается в наличии сети непрерывных каналов, которые могут быть исполь-зованы для различных практических применений (ион-обменных мембран, систем разделения, ката-лиза) [21]. Стоит подчеркнуть, что в образце сосуще-ствуют две кубические фазы, что предполагает их метастабильный характер.…”

“…These phases are an organic zeolites. Their main advantage is the occurrence of a network of continuous channels that can be used for various practical applications (ionexchange membranes, separation systems, catalysis) [21]. It should be emphasized that two cubic phases coexist in the sample, which suggests their metastable nature.…”

Polymerizable wedge-shaped ionic liquid crystals for fabrication of ion-conducting membranes: Impact of the counterion on the phase structure and conductivity

“…In a previous work, we have shown how the use solvent-mediated lyotropic transitions can be used to tune the channel structure of the Na-derivative [23,24]. In the present paper, we focus on the effect of the counterion in the thermotropic phase behavior of the different mesophases as well as on their ion conducting properties.…”

Polymer conformation in supramolecular complexes with wedge-shaped ligands: Exploring the impact of the liquid-crystalline organization

“…Previously, we have designed a series of wedge-shaped amphiphilic molecules containing a large hydrophobic rim and a hydrophilic sulfonic acid group at the focal point, which can self-assemble into lamellar and columnar structures [25][26][27][28][29][30]. It was further demonstrated that the complexes of poly(4-vinylpyridine) (P4VP) with wedge-shaped sulfonic acid molecules exhibited a liquid-crystalline lamellar phase at lower degrees of neutralization (DN), while formation of a hexagonal columnar mesophase was observed at higher DN [27].…”