Fabrication of SiO₂ wrapped polystyrene microcapsules by Pickering polymerization for self-lubricating coatings

The facile and efficient encapsulation of a lubricant oil in SiO₂ wrapped polystyrene microcapsules is accomplished using a Pickering polymerization technique. Triton X-100-IPTS fumed SiO₂ nanoparticles are used as emulsifiers for the formation of O/W Pickering emulsions and the stability factor of the Pickering emulsions was investigated. The as-obtained microcapsules are characterized by scanning electron microscope, thermogravimetric analysis, Fourier transform infrared spectra and dynamic laser scattering. These results suggest that the microcapsules display a spherical shape with a core content of ∼38.3%, an average diameter of 3.3 μm, a shell thickness is ∼900 nm and outstanding thermal stability for lubricant oil with a decomposition temperature of 250 °C. Moreover, the microcapsules are embedded into an epoxy resin for self-lubricating coatings. On the basis of frictional coefficient measurements and wear testing, the self-lubricating microcapsules-incorporated epoxy coatings on an aluminum plate indicate the excellent dispersibility of the microcapsules in coatings and the favorable antifriction effects.