A Brookfield DV-II + Pro rotational viscometer was used to study the viscosity of 7 samples of concentrated nanodispersed systems (nanofluids) with a similar viscosity (6-22 mPa ∙ s), the particles of the dispersed phase in which are nanosized surfactant micelles and conglomerates from them. It was found that for 5 out of 7 studied reagents, there is a decrease in viscosity typical for dispersed systems with an increase in the shear rate, and their flow curves, that is, the dependence of the shear stress on the shear rate, correspond to the ideal plastic flow of non-Newtonian fluids. Moreover, with high reliability, R2 ≥ 0.999 is described by the Bingham equation with a small value of the limiting shear stress (less than 0.2 Pa). It is shown that all the studied reagents are also characterized by an increase in the activation energy of a viscous flow Е with an increase in the shear rate. As a result, a decrease in viscosity with an increase in shear rate, typical for disperse systems, including nanofluids, is provided by a more significant increase in entropy changes ΔS compared to Е. It has been substantiated that, depending on the ratio between the activation energy of viscous flow Е and the change in entropy ΔS, the viscosity of concentrated micellar dispersed systems with an increase in the shear rate can decrease, remain unchanged, and increase. The last two cases, not typical for disperse systems and nanofluids, were identified and studied using the example of two demulsifiers, RIK-1 and RIK-2, with a maximum of a very narrow particle size distribution at 160 ± 5 nm, corresponding to the size of a special type of very stable micelles Surfactant — vesicle.

Using a rotary viscometer Brookfield DV-II+Pro, the viscosity of an almost one-component (1-2% impurity) sample of synthanol ALM-7 was studied. In the presented work, this reagent is use as a sample of a highly viscous non-Newtonian fluid and a concentrated micellar disperse system, the particles of the dispersed phase in which are micelles from molecules of this surfactant with dimensions less than 10 nm. Using the example of such a fluid, it is shown that the decrease in viscosity observed in it, typical for dispersed systems, as the shear rate increases, is accompanied by an increase in the activation energy of the viscous flow, which is inconsistent with the Arrhenius and Frenkel equation. The reason is that these equations do not take into account the changes in entropy ∆S during the viscous flow of the non-Newtonian fluid, the value of which actually determines the sign of the change in the viscosity of the non-Newtonian fluid with increasing velocity or shear stress. The only way to calculate ∆S now based on the use of the Eyring equation. However, for the correct calculation of ∆S by the temperature dependence of the dynamic viscosity of the non-Newtonian fluid and the Eyring equation, an independent correct way of finding the value of the preexponent B in this equation is necessary. The article analyzes the methods described in the literature for calculating the values of B, including those proposed by Henry Eyring himself. As a result, it was revealed that only the experimental method we developed for estimating the values of B corresponds to real processes in the non-Newtonian fluid, since only with such calculations does an increase in temperature and shear deformations lead to values of ∆S > 0, indicating the destructive effect of these factors on the non-Newtonian fluid. It is shown that other methods of calculating B can lead to incorrect values of ∆S < 0 and, as a consequence, erroneous conclusions about the processes occurring inside the non-Newtonian fluid.

Using the example of water in the usual bulk state, as well as in the bound state inside the sorbent of fine river sand and drops of water-oil emulsion, it is substantiated that the dielectric parameters of water bodies in the frequency range less than 20 MHz significantly depend not only on the frequency, but also on the electric field intensity E in which these parameters are located. A change in E by several orders of magnitude in this work is provided by using two types of measuring cells — capacitor (C-cells) and inductive (L-cells), as well as measuring instruments with different operating principles. A sharp change in low-frequency relaxation processes in the usual bulk state of liquid water occurs when E decreases to a level at which conduction currents cease to arise in water and a further decrease in E has little effect. Relaxation processes only for the most mobile part of its molecules, and in very high fields realized in C-cells, on the contrary, only about the most bound molecules in its first adsorption layers. At the same time, the dielectric parameters of water-oil emulsions turned out to be sensitive to the presence of water droplets in them only in strong electric fields of C-cells. Thus, in this work, it is revealed for the first time that the stronger the interaction of water with the surrounding molecules in an object, the the higher values of E should be used to study low-frequency relaxation processes in it by the dielectric method.