Influence of shear on polymer adsorption at solid / liquid interfaces

Lubricants contain a complex mixtures of polymers and base oils that must provide protection to moving surfaces with minimal energy loss due to friction or viscous drag. There is considerable interest in the relationship between bulk and interfacial properties of lubricants, especially under the extremes of pressure, temperature and shear rate are routinely found in engines. Here we propose a simple model system, based on polybutadiene and squalane, for which we have already established the phase behaviour under quiescent conditions. Interestingly, rheometry using a multi-pass rheometer indicates that phase separation may occur under moderate shear rates. We will use NR to determine surface segregation under quiescent conditions and under shear using a new setup on INTER. Results will give valueable insights into the modes of action and failure in model lubricants.