Self-assembly of nanoparticles at the interface between two fluids, and
methods to control such self-assembly process, e.g., the surface density
of particles assembling at the interface; to utilize the assembled
nanoparticles and their ligands in fabrication of capsules, where the
elastic properties of the capsules can be varied from soft to tough; to
develop capsules with well-defined porosities for ultimate use as
delivery systems; and to develop chemistries whereby multiple ligands or
ligands with multiple functionalities can be attached to the
nanoparticles to promote the interfacial segregation and assembly of the
nanoparticles. Certain embodiments use cadmium selenide (CdSe)
nanoparticles, since the photoluminescence of the particles provides a
convenient means by which the spatial location and organization of the
particles can be probed. However, the systems and methodologies presented
here are general and can, with suitable modification of the chemistries,
be adapted to any type of nanoparticle.