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  5. Use of liquid-crystalline compounds as antifriction and antiwear additives for lubricants

Use of liquid-crystalline compounds as antifriction and antiwear additives for lubricants

S. Voronin, N. Anoshkina, N. Gorbachov, S. Kupyanskij
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Description: Reduction of equipment deterioration is an important task of modern tribology. Modern machines and mechanisms contain a lot of rubbing parts. The simplest and most effective way to reduce their wear is to use lubricants, but under high temperatures and other harmful factors, the properties of oils and greases deteriorate over time. To The production sector has developed and successfully used a large variety of additives. They help reduce wear, increase lubricating efficiency, reduce the dependence of viscosity on temperature, etc. Scientists are still searching for other substances that could act as additives. They are actively exploring liquid crystals. Combining the properties of a fluid (fluidity) and a solid body (anisotropy), these substances form boundary films on the surface, which have a high carrying capacity and, at the same time, low friction in their balls. There are different types of liquid crystals. According to the method of production, there are thermotropic and lyotropic liquid crystals. According to the location of molecules, there are three main types: nematics, smectics, and hollesters. Each type of liquid crystal has its own properties. The article discusses liquid crystal substances that could be used as additives, tells about their chemical and physical properties, and explains the expediency of their use as lubricant additives. In addition to choosing additives, the article considers ensuring their active participation in the formation of polymolecular boundary films. The author of the article has conducted a search and analysis of literary sources on this topic, and found out that the effect of cholesteric liquid crystals on the friction process has not been sufficiently investigated. Thus the scientific investigation deals with the search for optimal concentrations of cholesteric liquid-crystalline additives in lubricants used for construction equipment and vehicles, taking into account the working temperatures in the friction pairs of these mechanisms and the temperature of phase transitions of the chosen liquid crystals.


Keywords: liquid crystals, additives, lubricants, friction, cholesterics

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Reference:
 Voronin, S.V., Anoshkina, N.M., Horbachov, M.V. and Kupianskyi, S.D. (2019), “Vykorystannia ridkokrystalichnykh spoluk v yakosti antyfryktsiinykh ta protyznoshuvalnykh prysadok do mastylnykh materialiv mobilnykh mashyn” [Use of liquid-crystalline compounds as antifriction and antiwear additives for lubricants], Scientific Works of Kharkiv National Air Force University, Vol. 1(59), pp. 65-72. https://doi.org/10.30748/zhups.2019.59.09.