The development of integrated micro- and nano-scale methods for the assembly, manipulation and characterization of complexes formed by amphiphiles and polymers underlies efforts to accelerate the discovery of new functional materials, drug formulations and consumer products. Key challenges that underlie the realization of integrated micro- and nano-scale chemical systems include reagent manipulation (e.g., transport/transfer of molecules between solution environments), separation of reactants and products, as well as product characterization. The ultimate limit to the scaling down of such integrated processes is to work with single assemblies (i.e., single nano-containers). Reaching this limit, however, requires the development of methods for manipulation of single assemblies as well as methods that permit characterization at the single assembly level.

As a part of this project, we report the development of principles for manipulation and characterization of assemblies formed by amphiphiles and polymers at the single assembly level.

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We use nematic solvents, solvents that possess long-range orientational ordering of the constituent molecules. In contrast to water and other isotropic solvents, the long-range ordering of molecules in nematic solvents permits tailoring of solvent structure on the nanometer-scale by introduction of so-called topological defects. Topological defects arise in nematic solvents when surface-imposed orientations frustrate the packing of solvent molecules, leading to nanoscopic regions of solvent with diminished levels of orientational order and high free-energy density. The high free energy density of the disordered solvent in the defect core has been shown to trigger the formation of well-defined assemblies of both small-molecule amphiphiles and polymers at concentrations below which assemblies form in the bulk nematic solvent phase.