نجمه فرزین نژاد

Lubrication plays an important role in the correct movement in contact surfaces، consistently and economically. Nowadays، in order to reach a considerable efficiency، all mineral and synthetic based lubricants require additives that can create certain properties. In recent years، nanotechnology and synthesis of nanomaterials have helped to reach new types of additives for lubricants with unique properties. These new additives have attracted lots of attention because of their unique properties and energy saving. In this paper we introduce and evaluate the used nanoadditives in lubricants، according to the conducted research in this area. It is believed that by using these additives، it would be possible to improve most fundamental properties، such as flash point، viscosity، pour point and resistance to friction، of lubricating oils.

Due to increased demands on lubricants، there is a need to develop new lubricants and improved additives. Ionic liquids (ILs) are room temperature molten salts that have recently shown many advantages in this area. The application of ILs as lubricants in a diverse range of systems has found that these materials can show remarkable protection against wear and reduction of friction. ILs consists of large asymmetrical ions that can readily adsorb onto a metal surface and produce a protective film under boundary lubrication conditions. This article starts with a brief introduction to ILs and fluid lubrication، and then discusses in more detail the tribological properties of IL lubricants، either as base and synthetic oil additives. In this article the correlation between the IL structure and their performance in tribology applications is examined. Finally، some current problems and potential solutions are discussed.

In this paper, one of the most recent methods of desulfurization of fuel on which there has been a large number of researches since 2001, has been used. To achieve low sulfur levels in fuel, desulfurization of domestic and imported gasoline has been assessed by using several types of ionic liquids (green solvents). Additionally, by using experimental design and statistical software, the variables affecting the desulfurization efficiency have been determined and optimum conditions have been used for higher desulfurization efficiency. In this study, physical and chemical properties of gasoline especially the amount of sulfur content have been determined before and after each extraction. By evaluating the achieved results, it was found that ionic liquids or green solvents have a great impact on removing aromatic sulfur compounds. As a result, ionic liquid extraction can be used as a complementary method for HDS in deep desulfurization.