Self-organization of macromolecules and liquid-crystalline phase transitions in solutions of cellulose esters

Polymer Rheology

“…The application of the magnetic field leads to development of the domain structure as a result of additional orientation of macromolecules in the field. Similar data were obtained for other systems having liquid crystalline transitions [57,58,62,70,71,73,75,76]. In accordance with [32,86,87], macromolecules orient in the magnetic field with their long chains arranged parallel to the force lines.…”

“…Since 2006, researchers of the Chair of Macromolecular Compounds, Ural State University (since 2011 Ural Federal University), have been involved in systematic investigations of the effect of magnetic field on the phase transitions, structure, and rheological properties of liquid crystalline solutions of cellulose ethers. It was found [57][58][59][60][61][62][63][64] that application of a magnetic field leads to a change in the type of liquid crystals from cholesteric to nematic, causes formation of domains in solutions, and entails a substantial (by tens of degrees) increase in the temperature of formation of liquid crystalline phases. As the molecular mass of a polymer is increased, the ability of its molecules to orientate in the magnetic field is reduced.…”

Phase equilibrium, structure, and rheological properties of the carboxymethyl cellulose-water system

“…Note that such an orientation is related not to the presence of permanent magnetic domains but to the molecular diamagnetic anisotropy of macromolecules. This cir cumstance leads to the formation of supramolecular particles, especially in the vicinity of the LC phase transition [4,6,7].…”

“…In recent years, the phase transitions, structure, and rheological properties of solutions of rigid chain polymers (cellulose ethers) have been studied at the Chair of Macromolecular Compounds, Ural Federal University [1][2][3][4][5][6][7]. The molecules of cellulose and its derivatives are characteristic of a rigid helical confor mation and capable of ordering via the formation of cholesteric liquid crystals in concentrated solutions [8].…”

“…The molecules of cellulose and its derivatives are characteristic of a rigid helical confor mation and capable of ordering via the formation of cholesteric liquid crystals in concentrated solutions [8]. The additional orientation of these macromole cules induced by a magnetic or mechanical field is responsible for broadening of the temperature-con centration region of LC phase existence and addi tional organization of macromolecules [1,4,6,7]. The first studies of the viscosity of rigid chain polymer solutions are described in [9][10][11][12][13].…”