Mechanism of tribofilm formation with P and S containing ionic liquids

Tribological Properties of Novel Multi-Walled Carbon Nanotubes and Phosphorus Containing Ionic Liquid Hybrids in Grease

“…Higher magnification image of grease blend containing MWCNT-P IL2 as an additive shows severe delamination and adhesive wear. Sharma et al studied the tribological performance of phosphonium cation based ILs in mineral base oil and reported a similar type of wear tracks with uneven distribution of formed antiwear films and the roughness oriented in the direction of rubbing (Sharma et al, 2015). The lubricating grease containing N IL1 and MWCNTs exhibits the smearing type of adhesive wear with deep scratches all over the worn surface.…”

“…Tribofilms formed on interacting surfaces provides low shearing strength, which leads to lower coefficient friction and excellent wear resistance (Fuller et al, 1997;Chen and Liu, 2001;Aktary et al, 2002;Qu et al, 2009aQu et al, , 2014Kim et al, 2010;Olomolehin et al, 2010;Somers et al, 2010;Otero et al, 2014;Sharma et al, 2015Sharma et al, , 2016Blanco et al, 2017). Many authors have proposed that the ionic liquids form tribofilms similar to ZDDP (Somers et al, 2013;Ghandi, 2014;Qu et al, 2014;Sharma et al, 2015). ZDDP forms tribofilms of zinc phosphates, zinc sulfides/sulfates, iron phosphate, and iron sulfides/sulfates and imparts excellent antiwear, and antifriction protection of surfaces in contact.…”

“…Many studies have used ILs with cations like imidazolium (Lu et al, 2004;Mu et al, 2005;Jiménez et al, 2006;Jiménez and Bermúdez, 2007), ammonium (Qu et al, 2006(Qu et al, , 2009b, pyridium (Kinzig et al, 2005;Qu et al, 2009a) along with halogen anion counterparts like BF − 4 (Ye et al, 2001;Phillips and Zabinski, 2004;Mu et al, 2008) and PF − 6 (Phillips and Zabinski, 2004;Yu et al, 2008) and have reported problems of tribocorrosion and poor/incomplete miscibility of these ILs in non-polar oils. Most novel choline cation (Gabler et al, 2011;Pisarova et al, 2012;Sharma et al, 2015Sharma et al, , 2016 and phosphonium cation (Liu et al, 2006;Qu et al, 2009aQu et al, , 2011Qu et al, , 2012Qu et al, , 2014Minami et al, 2010;Yu et al, 2012;Sharma et al, 2015Sharma et al, , 2016 based ILs are described to have excellent oil miscibility, thermal stability, non-corrosiveness and antiwear/antiscuffing capabilities when used as additives in mineral base oil or PAO oil. Motivated from this, the present goal of this study is to assess the potential use of choline and phosphonium cation ILs as additives in lubricating greases.…”

Antifriction and Antiwear Properties of an Ionic Liquid with Fluorine-Containing Anion Used as Lubricant Additive

“…Phosphorus and sulphur were not detected in the sample assayed with neat A2, as was to be expected; although the two elements could not be found in the other samples either. The absence of P can be explained if we bear in mind that phosphorus is only found in the cation and it has been reported that it is principally the anion which interacts with the surface [64]. The lack of sulphur on the surface is probably due to a problem related to the sensitivity of the measuring instrument to this element rather than to a real absence of it.…”

Lubrication performance of an ammonium cation-based ionic liquid used as an additive in a polar oil

“…On the other hand, only few works have used ILs as an additive in fully-formulated oils [27,34,[52][53][54][55] but more *Manuscript Click here to view linked References studies are necessary in order to know the compatibility of the ILs with other surface-adsorbing additives [6].…”