A novel application of mesoporous silica nanospheres on effective retention and delivery of lubricating oil

Mesoporous silica nanospheres (MSNs), with neat morphology, large Brunauer–Emmett–Teller (BET) surface area and uniform pore diameter, have been synthesized firstly, and then the liquid paraffin as lubricating oil is poured into the pores of the MSNs via a simple wet impregnation method to form paraffin-containing MSNs (abbreviated as PMSNs). The tribological tests are carried out under three different loads (1.0, 1.5, and 2.0 N) by sliding a steel ball (φ = 6 mm) against PMSNs thin films spin-coated on glass slides. The results indicate that the friction coefficient of glass slide reduces greatly from 0.7 to 0.09 due to the effective release of liquid paraffin preserved inside the pores of MSNs under these loads. Meantime, the corresponding wear volumes of glass slides also decrease greatly after the formation of the PMSNs film. As a result, the present work lights a pharos to utilize lubricating oil more effectively via releasing oil preserved inside the pores of the MSNs.