(678i) Synthesis and Characterization of Bioinspired Hierarchically Self-Assembling Organic-Inorganic Nanocomposites

Bioinspired self-assembling hybrid materials with hierarchical order were synthesized using bottom up approaches. Synthetic polymers or their conjugates with biomineralization proteins/peptides were used as templates for the bioinspired synthesis of calcium phosphate, magnetite, and zirconia nanocomposites. These nanocomposites were synthesized using amphiphilic triblock and pentablock copolymer templates that self-assemble at the nanoscale and at the macroscale based on changes in temperature and/or pH. Similar to native bone, citrate was added as a regulatory element in the in vitro synthesis of the calcium phosphate nanocomposites to enable molecular control of the size and stability of HAp nanocrystals. Uniform superparamagnetic magnetite nanocrystals with a size of about 30 nm, were only synthesized in the presence of a recombinant wild type Mms6 protein, and not by its mutants, indicating that the number and placement of charged groups in the protein were very critical for its function. Zirconia nanocomposites were synthesized using lysozyme conjugated to block copolymer templates. Removal of the templates left behind a porous network of zirconia with a much higher surface area and thermal stability than those made without any template. Based on these studies, we developed a robust and modular method with control over the formation and the placement of an inorganic phase in the nanocomposite structure, and are able to design tailored functional organic templates for room-temperature bioinspired synthesis.