Reverse Micelles and Encapsulated Nanoparticle Approaches

Jean Louis Mansot and Jean Michel Martin 4.1 Introduction 

Complementary analytical studies of the surface films using Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edges structures (XANES) [7, 8] lead to an accurate description of the antiwear film mainly composed of amorphous Ee/Zn poly(thio)phosphate embedding some nanocrystallites of ZnO and ZnS. The chemical reaction involved in the build-up of the tribo-film were recently interpreted with new theoretical approaches (hard and soft acid-base theory) [9, 10]. The action process of anti wear additives such as ZDDP presents two disadvantages  

Nanolubricants Edited by J. M. Martin and N. Ohmae 2008 John Wiley Sons, Ltd. ISBN 978-0-470-06552-5 

In addition, the new constraining environmental European standards aiming to reduce the sulfur and phosphorus contents in lubricating oil, which could lead to the replacement of ZDDP antiwear additives. 

This chapter is concerned with the development of an alternative way to build up the protective tribologic fihn between sliding surfaces that does not imply a chemical reaction of the additive with the substrates in contact. The approach is based on the use of nano-sized particles of tribologic film precursors consisting of reverse micelles or encapsulated mineral particles. First an overview of the various systems that could be used will be presented. Some examples of each case will then be deeply analysed (characterization of the colloidal system, tribologic properties, antiwear film structure and morphology and antiwear action mechanisms). 

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