Influence of Surfactants on the Tribological Behavior of Nanoparticle Additives Under Boundary Lubrication Conditions

Lubricants can significantly improve the anti-wear performance and prolong the service life of machines. It has been found that the introduction of additives can further enhance the performance of lubricating oil and meet harsh working conditions, such as high temperature, high speed, and high load. In this study, 1% by weight of CuO, WC, and WS2 nanoparticles were added to Polyalphaolefins (PAO) base oil to evaluate tribological response. The study focused on using different surfactants including Oleic acid (OA) and Polyisobutylene succinimides (PIBS), to determine their impact of agglomeration and the observed tribological response in the boundary lubrication regime. The results showed that adding 10% OA while sonicating the particles for 30 min reduced the agglomeration the most, and adding 1% OA while sonicating for 120 min produced a more uniform dispersion of the nanoparticles used in this study. Friction studies showed that the nanoparticles additives do not appreciably impact the friction compared to base oil. Wear resistance was improved by about 60% for CuO and WC with 1% OA and sonicated for 120 min. The study suggests that conditions that minimize agglomeration and promote high dispersion lead to favorable wear resistance under boundary lubricant conditions.

Automated summary

Lubricants can improve the anti-wear performance of machines by adding nanoparticles and surfactants, with favorable wear resistance achieved under boundary lubricant conditions by minimizing particle agglomeration and promoting high dispersion.