Complex-Shaped Microcomponents by the Reactive Conversion of Biology Templates
Abstract
This project has been aimed at: 1)developing a better understanding of the manner in which the morphology and nanostructure of biologically-derived silica microtemplates evolve during the course of reactive conversion, and 2) determining which reaction parameters have the greatest impact on changes in morphology during such reactive conversion. The most significant accomplishments have been: Demonstration (via high resolution TEM analyses) that the reaction of SiO2 diatom frustules with Mg(g) at 650 degrees C results in direct conversion into nanocrystalline MgO and Si(<15nm) without the formation of intermediate silicate phases. Syntheses of mgO-converted frustules with minimal secondary phases (Si or Mg2Si) by development of an optimized thermal treatment and selective dissolution treatment. Identification and control of critical processing parameters to avoid active vaporization and gas-phase-assisted coarsening during the metathetic conversion of SiO2 frustules into TIO2 Successful syntheses of ZrO2 frustule replicas via a new two-step reaction process (conversion of SiO2 into Mg(g) reaction; then conversion of MgO into ZrO2 via ZrCl4(g) methathetic reaction and selective MgCl2 dissolution in water).
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 15, 2003
- Accession Number
- ADA434603
Entities
People
- Kenneth H. Sandhage
- Rajesh R Naik
Organizations
- Georgia Tech Research Corporation