Publications by authors named "K N Grafskaia"

Six different flexible stereocontrolled oligo(triazole-urethane)s substituted by precise sequences of nucleobases or analogs are synthesized. Molecular dynamics simulations indicate that the flexibility of the backbone leads to unspecific complexation of pairs of oligomers, irrespective of the complementarity of their sequences. This is ascribed to the existence of other interactions between pairs of oligomers, as well as to the spatial blurring of the sequence order encoded in the chemical structure of the chain due to its flexibility.

View Article and Find Full Text PDF

We report on formation of a bicontinuous double gyroid phase by a wedge-shaped amphiphilic mesogen, pyridinium 4'-[3″,4″,5″-tris-(octyloxy)benzoyloxy]azobenzene-4-sulfonate. It is found that this compound can self-organize in zeolite-like structures adaptive to environmental conditions (e.g.

View Article and Find Full Text PDF

Aqueous microgels based on poly(N-vinylcaprolactam) with reversible temperature-induced volume transition are promising "smart" materials for various applications. In this work, the microgels are modified via acid-base interaction by wedge-shaped amphiphilic sulfonic acid molecules with alkyl chains of different lengths and an azobenzene group. In contrast to the pristine microgel the modified microgels retain colloidal stability in water and show different responses to the change of temperature and pH.

View Article and Find Full Text PDF

We report on the phase behaviour of a wedge-shaped mesogen, which can exist in two different states at room temperature, a stable columnar and a metastable cubic gyroid phase. The latter reveals exceptional stability and remarkable water sorption capacity accounted for by the locally-ordered peripheral alkyl chains.

View Article and Find Full Text PDF

In supramolecular assemblies, absorption of water can assist the channel formation, similarly to biological systems and Nafion-like commercial ion-selective membranes. In this work, we investigate humidity-induced formation of water channels in wedge-shaped amphiphilic molecules, namely sodium 4'-[3'',4'',5''-tris(alkyloxy)benzoyloxy]azobenzene-4-sulfonates. The studied molecules contain a polar sulfonate group at the tip and a hydrophobic periphery composed of alkyl chains of two different lengths.

View Article and Find Full Text PDF