Surface regulation of silicon dioxide nanoparticle and its tribological properties as additive in base oils with different polarity

Silica nanoparticle primarily surface-capped by amino radical was further modified by polyisobutylene succinic anhydride. The tribological properties of RNS-1A-PIBSA nanoparticle as additive in the three kinds of base oils were evaluated and compared with an oscillating reciprocal friction and wear tester (SRV-5). In DIOS with a high polarity, however, RNS-1A-PIBSA nanoparticle has nearly no influence on the friction reducing ability of the base oil. Namely, the lowly polar base oil PAO6 and moderately polar base oil AN5 do not disturb the adsorption of the nano-additive on rubbed metal surface and the formation of relatively thick deposited film; the highly polar base oil DIOS, however, competes with the nano-additive and hinders the adsorption of the nano-additive thereon.