Optimization Efficiency of Nano Emulsion Surfactants as Base Oil Antioxidants and Anti-wear Additives
Noura El Mehbad *
Faculty of Science, Najran University, Najran, Kingdom of Saudi Arabia
*Author to whom correspondence should be addressed.
Abstract
N-hexadecyl-N-benzyl-N-methylglycine and N-Dodecyl-N-benzyl-N-methylglycine were studied as antioxidants and anti wear. The physico-chemical properties were investigated; the adsorption behavior of these compounds at oil interface was investigated by measuring the surface tension and interfacial tension as function of concentration. Surface properties, in particular the critical micelle, the maximum surface excess and the minimum surface area were measured. It is found that the surface and thermodynamic properties of the prepared surfactants depend on their chemical structure. Also it is found that there is a good relation between surface properties of the additive and their efficiency as antioxidants. The mechanism of the antioxidation action has been suggested according to the surface properties of each additive. Adsorption of the additive on the surface interface inhibits their free radicals trapped in micelle core. These compounds were added to oil in different concentrations. The antioxidants activities of different dosages were evaluated. The oxidation of the oil has been carried out for different time intervals. The degradation of the oil has been monitored by total acid formation. The anti wear characteristic of surfactants increase with increasing hydrocarbon chain length. This is due to the increase in chemisorptions of surfactants on the silicon carbide surface. These films provide lower wear and depend on amount of surfactants concentration adsorbed on silicon carbide and sliding speed. These studies have led to determine the effect of adsorbed surfactants in dispersion of nano particles of silicon carbide in oil phase. The anti wear characteristic of surfactants increase with increasing dispersed silicon carbide. These studies have led to much clear evidence of the intimate relationship between the chemical structure of the surfactants and dispersed silicon carbide.
Keywords: Additives, anti wears, surfactants, base oil Introduction