The review presents current research results for Carbopol-based microgels as yield-stress materials, covering three aspects: chemical, physical and rheological. Such a joint three-aspect study has no analog in the literature. The chemical aspects of Carbopol polymers are presented in terms of a cross-linking polymerization of acrylic acid, their molecular structure, microgel formulation, polyacid dissociation and neutralization, osmotic pressure and associated immense microgel swelling. The physical characterization is focused on models of the shear-induced solid-to-liquid transition of microgels, which are formed of mesoscopic particles typical for soft matter materials. Models that describe interparticle effects are presented to explain the energy states of microgel particles at the mesoscale of scrutiny. Typical representatives of the models utilize attributes of jamming dispersions, micromechanical and polyelectrolyte reactions. Selected relationships that result from the models, such as scaling rules and nondimensional flow characteristics are also presented. The rheological part presents the discussion of problems of yield stress in 2D and 3D deformations, appearance and magnitude of the wall slip. The theory and characteristics of Carbopol microgel deformation in rotational rheometers are presented with graphs for the steady-state measurements, stress-controlled oscillation and two types of transient shear deformation. The review is concluded with suggestions for future research.

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This paper presents experimental investigations of the influence of a newly constructed agitator on mixing time. Two kinds of movement (rotating and reciprocating) of a nontypical agitator are discussed. Moreover, the influence of simultaneous rotating and reciprocating movements of the agitator on the homogenization process of a mixed liquid is analyzed. The proposed dimensional analysis of the Navier−Stokes equation is allowed to describe the analyzed process by means of a relationship based on dimensionless numbers (mixing time number, rotating or reciprocating Reynolds number). The obtained results suggest that the homogenization time for the tested experimental setup may be worked out by use of the relationship between the mentioned dimensionless mixing time number and the rotating or/and reciprocating Reynolds number. Important conclusions from the discussion of experimental studies of the mixing process are also specified.

This study reports on research results in the fi eld of a mixing process under the action of a transverse rotating magnetic fi eld (TRMF). The main objective of this paper is to present the effect of this type of a magnetic fi eld on residence time distribution (RTD) measurements. This paper evaluates the performance of a magnetic mixer by comparing the results of an experimental investigations in a pilot set-up and theoretical values obtained from mathematical model. This model consisting of the set of ideal continuous stirred tank reactors (CSTR) fi tted well the experimental data.