Chemical analysis of overbased calcium sulfonate detergents by coupling XPS, ToF-SIMS, XANES, and EFTEM

Influence of Organo-Sulfur Compounds with Overbased Calcium Compounds on Lubrication in Cold Forming

“…As Figure 18a shows, the deeper the position in the film, the higher the relative intensity derived from sulfide. This suggests that the soap is being adsorbed on the outermost surface side as reported in the previous studies [6,17]. Calcium was abundantly detected on the surface with iC8A + Ca-Su (Figure 14).…”

Characterisation of the Surfactant Shell Stabilising Calcium Carbonate Dispersions in Overbased Detergent Additives: Molecular Modelling and Spin-Probe-ESR Studies

“…The polar heads (sulphonate) are attached to the metal core, while the hydrocarbon tails of hydrophobic nature stabilize the colloidal particle in the non-polar oil medium. Coupling three surface analyses techniques (XPS, XANES and ToF-SIMS) it was observed that there is a presence of some residual calcium hydroxide in the micellar core which is located prevalently at the surroundings of the micelle core [9]. ToF-SIMS shows that the molecular structures of detergent molecules are in good agreement with micelles synthesis data; little is still known on surfactant shell physical nature.…”

In-situ reflection-XANES study of ZDDP and MoDTC lubricant films formed on steel and diamond like carbon (DLC) surfaces

“…In XAS analysis, the detection technique, either electrons (total electron yield) or photons (fluorescence yield), provides information on the chemical structure at different sample depths. In order to identify the chemical nature of tribofilm species, the obtained spectra are compared with the spectra of different model compounds with known chemistry [12,25,[27][28][29][30][31][32][33]. To enable non-vacuum environment analysis, hard X-rays are required.…”