Kolloidnyj žurnal

Water-salt solutions of interpolyelectrolyte complexes (IPEC) are a classic example of “smart” systems, the phase equilibrium in which is regulated by many factors associated with both the parameters of the polymer components and the physical and chemical properties of the environment. This paper presents a model created on the basis of machine learning for predicting the region of existence of water-soluble IPECs. An approach is proposed for independently taking into account the physicochemical properties of polyelectrolytes and the properties of the environment. The developed model is universal and can be used to predict the properties of multicomponent systems of various chemical natures.

In this study, the mechanical durability of a superhydrophobic coating fabricated on the basis of industrial epoxy enamel EP-140 was investigated. To achieve a superhydrophobic state, the applied coating was modified by pulsed laser texturing and fluorosilane chemisorption. The aim of the research was to evaluate the coating’s resistance to various mechanical loads typical for outdoor use: prolonged water contact, exposure to high-speed water jets, abrasive wear from falling sand, and multiple removals of adhesive tape. It was shown that the combined approach used in superhydrophobic treatment not only provides high water repellency but also significant resistance to degradation. Experiments revealed only a slight decrease in wetting characteristics, while the heterogeneous wetting regime was maintained, confirming that the coating retains its functionality even under extreme mechanical impacts. The obtained data indicate the promising application of the developed coating in industries that require a combination of high wear resistance and cost-effectiveness.

The aim of this work was to identify the possibilities of synthesizing stable latex with a narrow particle distribution by homogeneous polymerization in an aqueous solution of methyl methacrylate. The polymerization of methyl methacrylate was first carried out under static conditions in an aqueous solution of the hydroquinone–potassium persulfate oxidation-reduction system. It was assumed that semiquinone anion radicals formed at the intermediate stage of hydroquinone oxidation can participate in the reactions of termination of growing radicals and by changing the molecular parameters of polymer molecules, affect the process of formation of latex particles. The article presents the results of the study of the colloidal parameters of the obtained latex, which show that the selected polymerization conditions allow reproducibly synthesizing monodisperse stable latex.

One of the practical challenges in the oil and gas industry is the formation of acid-oil emulsions and asphaltene sludge when well stimulation fluids come into contact with oil. The key to solving these problems lies in understanding the processes at the interface between oil and these agents, which is the focus of this study. The research investigates the processes occurring between sensitive oil and two types of stimulation fluids based on hydrochloric acid and ethylenediaminetetraacetic acid (EDTA) with and without the addition of a surfactant. Three methods are employed: simple mixing («bottle test»), simultaneous flow of fluids in a capillary, and simultaneous flow of fluids in a micromodel simulating a porous medium. Using simple mixing, it is shown that adding a surfactant to 15% hydrochloric acid can prevent sludge formation but does not prevent emulsion formation. Additionally, it is found that EDTA-based compositions with a neutral pH are compatible even with sensitive oil. Simultaneous flow experiments demonstrate the role of capillary walls in creating sludge and the cleaning ability of the chelating agent. Simultaneous flow in the micromodel highlights the distinctive features of hydrochloric acid compared to the chelate discrete flow, emulsion formation in the near-wall layer, and precipitate formation on pore walls. The results of this study can be useful both for further fundamental research into colloidal-chemical processes in oil reservoirs and for practical applications.