| abstract |
A design strategy for constructing hierarchically structured materials using nanoparticles and synthetic biopolymers has been developed. Block copolypeptides or homopolymer polyelectrolytes are used as structure-directing agents to arrange nanoparticles (composed of metals, metal non-oxides, metal oxides, or organics) into unusual microstructures, such as spheres, “apples” and “cups.” Hollow spheres can be made wherein nanoparticles of one composition are spatially oriented completely interior or exterior to nanoparticles of a second composition. These aggregates contain nanoparticles only in the shell walls, and maintain their hollowness upon calcination. These shapes can also be fabricated into films. These robust materials are anticipated to have great promise in applications that require surface catalysis, magnetic/electronic/optic properties, transport capabilities, and combinations thereof, such as drug delivery, packaging, catalysis, and sensors. |