Biomineralized 3-D Nanoparticle Assemblies with Micro-to-Nanoscale Features and Tailored Chemistries
Final performance rept. Jan 2005-Dec 2007
GEORGIA INST OF TECH ATLANTA SCHOOL OF MATERIALS SCIENCE AND ENGINEERING
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This collaborative research project has focused on the integrated use of robust biomimetic or biological silica assembly processes with shape-preserving chemical conversion reactions to produce freestanding 3-D structures with selectable microscale morphologies, nanoscale features, and tailored, non-silica chemistries. Biomimetic 3-D silica structures have been synthesized through Direct-Write Assembly using polyamine-based inks, followed by templated conformal silicification. With proper selection of ink composition and silicification conditions, robust silica structures were formed that retained the patterned morphology after firing to 1000 C. Such 3-D biomimetic silica and biological silica diatom frustule structures were converted into freestanding 3-D silica-free replicas comprised of other oxides or metals through the use of gassolid reactions. For example, these 3-D silica structures were converted into high surface area, microporous Si replicas through reaction with Mg gas to yield MgO and Si products and then selective MgO dissolution. Such Si replicas have, in turn, been converted into noble metal replicas through electroless deposition and selective Si dissolution. The reaction kinetics and micronanostructural evolution during such reactions have been examined.
- Inorganic Chemistry