Triggering gel-sol transition by weak magnetic field.

The self-assembly of small and always chiral molecules into fiber-like structures is a mysterious process, as the physics underlying such self-assembly is unclear. The energy necessary for this process exceeds the one provided by common dispersion interactions and hydrogen bonding. The recent results obtained by the scientific group of Prof.

The role of exchange interactions in the stability of cellulose.

The problem of the origin of biochirality and the related problem of the initial monomer selection are still under discussion, and the main point here is not the mechanics of enantiomer separation but the problem of the role of chirality in the very early stages of evolution. A recent breakthrough in understanding the influence of a static magnetic field on non-magnetic systems can shed light on this complex problem. The phenomenon of magnetosensitivity of non-magnetic systems was reported for only chiral systems and was closely related to the ability of some chiral substances to self-assemble.

A gel lattice alters the phase state of a solvent.

Some low-molecular-weight substances are able to self-assemble into fiber-like structures (strings) to form gels. One of the examples of such substances is trifluoroacetylated alpha-aminoalcohols (TFAAAs) able to gelate in many organic solvents. Here we report the formation and describe the properties of a layer of an altered solvent covering the strings' surface.

Zhurkov's Stress-Driven Fracture as a Driving Force of the Microcrystalline Cellulose Formation.

Microcrystalline cellulose (MCC) is a chemically pure product of cellulose mechano-chemical conversion. It is a white powder composed of the short fragments of the plant cells widely used in the modern food industry and pharmaceutics. The acid hydrolysis of the bleached lignin-free cellulose raw is the main and necessary stage of MCC production.

The weak magnetic field inhibits the supramolecular self-ordering of chiral molecules.

The magnetic field can affect processes in the non-magnetic systems, including the biochemical reactions in the living cells. This phenomenon becomes possible due to the fermionic nature of an electron and significant energy gain provided by the exchange interactions. Here we report the inhibition effect of the magnetic field on the processes of the chiral supramolecular, i.

Chirality Driven Twisting as a Driving Force of Primitive Folding in Binary Mixtures.

The N-trifluoroacetylated α-aminoalcohols (TFAAAs) are able to form quasi-one-dimensional supramolecular fibers (strings) when chirally pure, and isometric precipitates in the racemate. The strings' formation leads to the reversible gelation of the solution. The fresh gels occupy all the available volume, however during the incubation, they contract and concentrate in the central region of the tube.

Structure and properties of helical fibers spun from cellulose solutions in [B]Cl.

Man-made fibers were spun from solutions of cotton and wood cellulose in ionic liquid (1-butyl-3-methyl-imidazolium chloride, [B]Cl). Depending on the concentration, cellulose dissolved in [B]Cl down to macromolecules or nanofibrils. The artificial fibers had a diameter of about 100 nm, were uniform, transparent, helical, and optically active.

Spontaneous Resolution and Super-coiling in Xerogels of the Products of Photo-Induced Formose Reaction.

This work addresses the supramolecular self-organization in the xerogels of formose reaction products. The UV-induced formose reaction was held in over-saturated formaldehyde solutions at 70C without a catalyst. The solutions of the obtained carbohydrates were dried on a glass slide, and the obtained xerogels demonstrated a prominent optical activity, while the initial solutions were optically inactive.

Twisting of Fibers Balancing the Gel⁻Sol Transition in Cellulose Aqueous Suspensions.

Cellulose hydrogels and films are advantageous materials that are applied in modern industry and medicine. Cellulose hydrogels have a stable scaffold and never form films upon drying, while viscous cellulose hydrosols are liquids that could be used for film production. So, stabilizing either a gel or sol state in cellulose suspensions is a worthwhile challenge, significant for the practical applications.