Viscosity of macromolecules with complex architecture

• Published in: Polymer (Guilford) Vol. 244; p. 124622
• Main Authors: Rudyak, Vladimir Yu, Sergeev, Artem V., Kozhunova, Elena Yu, Molchanov, Vyacheslav S., Philippova, Olga E., Chertovich, Alexander V.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 23.03.2022; Elsevier BV
• Subjects: Computer simulations; Crosslinking; Dispersions; Equilibrium methods; Hydrodynamics; Macromolecules; Mathematical models; Microgels; Molecular dynamics; Particle shape; Polymer rheology; Polymers; Reference systems; Rheological properties; Rheology; Shear thinning (liquids); Shear viscosity; Topology; Viscosity; Viscosity; Molecular dynamics; Polymer rheology; Computer simulations; Macromolecules; Microgels
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2022.124622

It is well-known that the architecture of macromolecules plays an important role in the hydrodynamics and viscosity of its semi-diluted solutions. However, the systematic study of the rheology of macromolecules with complex topology, such as microgels, remains a difficult task. In this work, we use the computer simulations methods of non-equilibrium molecular dynamics to study the viscous properties of randomly cross-linked microgels and compare it to multiple reference systems (linear chains, 10-arm star polymers and hard spheres). We show that the microgel cross-linking density and, thus, the particle shape, plays crucial role in its shear viscosity. Also, in contrast to a simpler polymer systems, microgel dispersions in good solvent show much less shear thinning. [Display omitted] •Viscosity of microgel solution is highly affected by dangling ends in its corona.•Solutions of microgels with high molecular mass can obtain low viscosity.•Microgel solutions demonstrate atypical dependency of viscosity on shear rate.•Rheological properties of microgels are strongly dependent on temperature.