(60c) Complex Polymer Architectural Designs for Interfacial Engineering
This presentation will emphasize recent studies of enhanced interfacial engineering performance achieved with complex polymeric architectures. It will also bring to bear some long-standing research themes from this group concerning the fundamental and practical importance of multi-component interactions and persistent non-equilibrium states in complex fluid interfacial systems. These concepts that were established with simpler polymer architectures in the 1990âs and 2000âs will be shown to be quite useful with the novel complex architectures being developed now. Interfacial engineering via polymer adsorption often relies on the persistence of non-equilibrium states in adsorbed layers, where the adsorbed layer configuration is hysteretic with respect to changing bulk conditions. Recognizing this situation opens up new opportunities to improve engineering performance by processing adsorbed layers into appropriate non-equilibrium configurations. The switchable boundary lubrication application of adsorbed brush-grafted nanoparticles nicely illustrates new opportunities to achieve some performance attribute that has not previously been achieved with simpler polymer architectures. It furthermore illustrates how non-equilibrium layer state processing may be necessary to do so. It is also quite common that a desired performance characteristic cannot be achieved by interfacial engineering with just a single surface active species. Commercially important multi-component mixtures have long been designed to provide desirable product performance through judicious specification of components that form multispecies complexes. The advantages of multi-component complexation of brush grafted nanoparticles with surfactants or with star polymers will be illustrated here in the context of emulsification synergism and lubrication control.