Self-organization of amphiphilic macromolecules with local helix structure in concentrated solutions

Abstract

Concentrated solutions of amphiphilic macromolecules with local helical structure were studied by means of molecular dynamic simulations. It is shown that in poor solvent the macromolecules are assembled into wire-like aggregates having complex core-shell structure. The core consists of a hydrophobic backbone of the chains which intertwine around each other. It is protected by the shell of hydrophilic side groups. In racemic mixture of right-hand and left-hand helix macromolecules the wire-like complex is a chain of braid bundles of macromolecules with the same chirality stacking at their ends. The average number of macromolecules in the wire cross-section is close to that of separate bundles observed in dilute solutions of such macromolecules. The effects described here could serve as a simple model of self-organization in solutions of macromolecules with local helical structure.

Quantum selfish gene (biological evolution in terms of quantum mechanics)

“…Language of quasi-particles allows to include electromagnetic field to the model and potentially take into account even cosmic factors of the evolution (see, for example, [19]). Quasiparticles exist in polymer molecules where rigid bonds between adjacent monomers in a linear chain decrease entropy of systems of such molecules so that the small energy pulses can greatly affect the dynamic scenario (see [14]). The variable part of the genome in the form of quasi-particles can serve as an internal physical mechanism of directed DNA changes leading to biological evolution, along with an external factor -viral and bacterial environment.…”

New strategy to create ultra-thin surface layer of grafted amphiphilic macromolecules

“…The hydrophilic shell prevents the bundle aggregation and favors the parallel location of the bundles in concentrated solution. 37 The phase diagram for the melt of copolymers with an amphiphilic block can be significantly different from that known for the conventional diblocks. 38,39 In the limit of significant amphiphilicity (surface activity), the resulting morphology corresponds to thin channels and slits of amphiphilic units penetrating through the matrix of a majority non-polar component.…”

“…In semidilute solution, the amphiphilic flexible macromolecules condense into individual soluble globules 31 while the rigid macromolecules tend to aggregate with formation of braid fibril-like complexes 36 or bundle aggregates of a few chains. 37 In both cases, the hydrophobic backbones of the chains intertwine and form a core, whereas hydrophilic groups are located on the surface. The hydrophilic shell prevents the bundle aggregation and favors the parallel location of the bundles in concentrated solution.…”

Vesicle‐Like Globules of Amphiphilic Macromolecules

“…To date, application of amphiphilic unit model allowed to reveal conditions necessary to obtain globules, soluble at high polymer concentrations; propose a model of self‐organization and fibrils formation in solvents of biological and biomimetic synthetic macromolecules; suggest an effective technique to create nanocapsules, to make ultra‐thin surface layers, and to design materials with specific crystalline‐like ordering of solvent; study of the structure of polyelectrolytes with pendant architecture in solutions …”