Posted: January 17, 2007

Direct pathway to ordered nanostructured ceramics

(Nanowerk News) Nano breakthrough could serve as the foundation to developing high-temperature nanoceramic materials with future applications in energy and aviation.
GE Global Research, the centralized research organization of the General Electric Company, today announced a promising breakthrough in nanotechnology that provides a direct pathway to making nanoceramic materials from polymeric precursors. Developing processes and a greater understanding of nano-engineered ceramics could lead to future applications in aviation and energy, where products such as aircraft engines and gas turbines could one day achieve new levels of efficiency, reliability and environmental performance.
A cross-disciplinary team led by Dr. Patrick R. L. Malenfant and Dr. Julin Wan made the discovery, which is reported in the January issue of Nature Nanotechnology.
The team developed a very simple synthesis for the polymeric precursor, which enables a very efficient path towards ordered non-oxide ceramic nanostructures. The technology is based on a novel inorganic/organic block copolymer that forms ordered polymeric nanostructures via self-assembly. The resulting material is subsequently pyrolized to yield the desired ceramic, in which the original nanostructure is retained. The unique aspect of the invention is that the desired composition and the ability to form ordered nanostructures are built in. No external template is needed, and the process is simple and robust.
Dr. Malenfant said, "Drawing from recent developments in the literature, we were able to develop a robust synthesis of well-defined block copolymers that doesn't require stringent atmospheric conditions and that readily assemble into ordered nanostructures upon solvent evaporation. Pyrolysis provides ceramic materials that retain their nanostructure up to 1400 degrees C."
Dr. Wan said, "Nanostructure engineering in high temperature ceramics is extremely challenging because of the limited number of options available at the high temperatures usually needed to make these materials. Our inorganic block copolymer precursor brings the molecular design of polymers into the realm of nanostructured ceramics. The well-developed science of block copolymer physics can then be utilized to predict and control the formation of a myriad of nanostructures in ceramics. This provides access to many structural motifs that have yet to be explored in these materials."
The development of nanoceramic materials is a key objective of GE's Nanotechnology Program at Global Research. Ceramics are extremely heat resistant but brittle materials. However, nature has demonstrated that through nanotechnology, ceramic materials can be made more durable. Non-oxide ceramics with increased toughness, combined with their intrinsic heat-resistant properties, could have broad applications for GE's Aviation and Energy businesses.
Dr. Malenfant and Dr. Wan point out that while damage tolerant high-temperature ceramics could revolutionize product development in aviation and energy, structural applications are still many years away. More immediate applications could result from the ability to prepare high surface area ceramics that could be exploited in catalysis.
Dr. Malenfant said, "Our method enables the synthesis of ordered, high surface area, mesoporous materials that could be explored as non-traditional catalyst supports. We expect the impact of this technology to spread far beyond the materials initially reported due to the powerful combination of synthetic polymer chemistry, polymer physics and ceramics processing."
Source: GE