(233a) Invited: Harnessing Instabilities Of Oil/Water Interfaces To Tailor Structure and Functionality Of Amphiphilic Polymer Assemblies

Micellar and microparticulate assemblies of amphiphilic polymers hold promise for a variety of applications in delivery of therapeutic compounds and imaging contrast agents. However, as such materials typically face large barriers against structural reorganization in aqueous environments, their assemblies are usually far from equilibrium, yielding great sensitivity of their structures to the route by which they were processed. Our group has studied the formation of micelles and microparticles through interfacial instabilities during the removal of volatile solvents from oil-in-water emulsions containing amphiphilic block copolymers. We have shown that this phenomenon is consistent with a nearly vanishing solvent/water interfacial tension that is expected upon a transition from a macrophase-separated emulsion to a microemulsion phase. Further, the morphologies developed through this process can be tuned by tailoring the composition of the copolymer as well as the concentration of small-molecule surfactants. Finally, we have studied the opportunities that this approach offers for the preparation of multi-functional micelles, containing several different types of inorganic nanoparticles, and of textured particles with interesting immunogenic properties.