Oily nanocoatings

Tribological performance of molecular thermoplastic elastomeric films grafted onto a silicon surface was enhanced by adding a minute amount of paraffinic oil, which was adsorbed by the rubber matrix. The nanocomposite films show bimodal distribution of the surface elastic modulus, caused by the nanodomain structure. Minute amounts of oil, trapped within the rubber phase after evaporation, modified the nanotribological properties of these layers. We observed a significant decrease of the friction coefficient by 40%, along with a lower elastic modulus of the rubber phase. We suggest that under high shear stresses and sliding velocity, oil molecules can be compressed out of the bulk to the surface, facilitating instant local lubrication of the contact area.