题 目：Shape-Preserving Chemical Conversion of 3-D Biogenic and Synthetic Structures into Replicas Tailored for Catalytic, Optical, Energy, and Aerospace Applications
报告人：Prof. Ken H. Sandhage （佐治亚理工学院）
Nature provides remarkable examples of microscale structures with complex three-dimensional (3-D) morphologies and finely-patterned (down to nanoscale) features formed by living organisms under gentle, ambient conditions. For example, intricate 3-D microscale silica or chitinous structures with periodic (or quasiperiodic) nanoscale features are formed by diatoms (single celled algae) or Morpho butterflies, respectively. Synthetic rapid-prototyping or self-assembly approaches have also yielded 3-D structures with microscale and/or nanoscale particles/pores in certain desired arrangements. While such 3-D patterned structures can be attractive for particular applications, the materials readily formed by these biogenic and synthetic processes may not possess preferred chemistries for a broader range of uses.
The scalable fabrication of structures with complex 3-D morphologies and with a range of tailorable chemistries may be accomplished by separating the processes for structure formation and for chemical tailoring; that is, structures with a desired 3-D morphology may first be assembled in a readily-formed chemistry and then converted into a new functional chemistry via a morphology-preserving transformation process. In this presentation, several shape-preserving chemical conversion strategies (fluid/solid reaction-based and conformal coating-based) will be discussed for generating 3-D replicas of natural and man-made structures comprised of ceramic, metal, or composite materials for catalytic, optical, energy harvesting/storage, and aerospace applications.
Ken H. Sandhage received a B.S. in Metallurgical Engineering with Highest Distinction from Purdue University and a Ph.D. in Ceramics from the Massachusetts Institute of Technology (1987). After working as a Senior Scientist on the reaction processing of optical fibers at Corning, Inc., and on the oxidation and deformation processing of high temperature superconductors at American Superconductor Corporation, he joined the Department of Materials Science and Engineering at The Ohio State University (1991). In the fall of 2003, Sandhage joined the School of Materials Science and Engineering at the Georgia Institute of Technology, where he is currently the B. Mifflin Hood Professor. Sandhage’s current research is focused on the gas/solid and liquid/solid reaction processing, and conformal coating (using wet (bio)chemical strategies), of biogenic and synthetic structures to yield functional 3-D materials for chemical, optical, electronic, energy, medical, and aerospace applications. He is currently the Principal Investigator and Co-Director of the Air Force Center of Excellence on Bio-nano-enabled Inorganic/Organic Nanocomposites and Improved Cognition (BIONIC) and is a Fellow of the American Ceramic Society.