Materials Synthesis

Synthetic Chemistry with Periodic Mesostructures at High Pressure

High-pressure synthesis has revolutionized the diamond industrial and it continues to play important roles in searching for new super-hard materials. It has been demonstrated that pressure can enhance materials properties and lead to new phenomena novel physical properties, which may be utilized to advance technology and design new materials. I have started to explore the role of pressure in materials synthesis, and established a new research avenue towards synthesis of novel carbon-based super-hard materials at high pressure. We have successfully synthesized the first stishovite (a high-pressure form of silica) nanocrystals in multi-anvil high-pressure device. We have been also very successful to synthesize new periodic crystalline mesoporous materials through high-pressure synthesis in high-pressure device, and to characterize the products with various analytical techniques including SEM, TEM, and wide- and small-angle X-ray scattering. Through nanocasting, we have made periodic mesoporous coesite, which is the first example of periodic mesoporous high-pressure phase with unique physical properties. We have also been exploring the layering structure of graphane at high pressure and its transition mechanism to diamond at high pressure.

Mesoporous materials belong to the most important classes of materials due to their wide structural diversity and broad range of applications including catalysis, separation, microelectronics, and drug-delivery. The emphasis of the research is to explore the role of high pressure in synthesis to produce mesostructures of diamond and investigate the mechanisms of phase transformations at high-pressure inside a mesostructure. Diamond is the arguably the most technologically important high-pressure phase. Mesostructured composites of diamond could find applications as ultrahard materials. Diamond is known as biocompatible material and thus mesoporous forms of diamond could have potential in drug-delivery.