Late at night on June 29th, Beijing time, the top international academic journal Nature simultaneously published two research articles on Professor Duan Xiangfeng from the University of California, Los Angeles . Professor Duan Xiangfeng was the only corresponding author of and respectively. Co-corresponding author . The two research results are titled "Chiral molecular intercalation superlattices" and "Hypocrystalline ceramic aerogels for thermal insulation at extreme conditions" respectively. New breakthroughs have been made in the field of high-quality chiral molecule intercalated superlattice materials and thermal insulation ceramic aerogels under extreme conditions.
Professor Duan Xiangfeng was born in Wugang, Hunan, China in 1977. He is a tenured professor at the University of California, Los Angeles, a distinguished professor at Hunan University, and a nanomaterials scientist. He received a bachelor's degree in chemistry from the University of Science and Technology of China in 1997, a master's degree in chemistry from Harvard University in 1999 and a doctorate in physical chemistry from Harvard University in 2002. From 2002 to 2008, he became the founding scientist of Nanosys Inc. Chief Scientist and Advanced Technology Manager, joined the Department of Chemistry and Biochemistry at UCLA in 2008. In 2011, he was selected into the 2000-2010 World's Top 100 Chemists Hall of Fame list and the World's Top 100 Materials Scientists Hall of Fame list released by Thomson Reuters Group. He has won the U.S. "Young Scientist Presidential Award" and the Belby Award. Medals and other important honors.
Professor Duan Xiangfeng’s research on inorganic nanostructures in recent years has made important contributions to the development of nanoscience and nanotechnology. Current research interests include heterogeneous integration of nanoscale materials, development of novel nanoscale device concepts, and exploration of applications in future electronics, energy science, and biomedical sciences.
Chiral molecule intercalated superlattice materials
Professor Duan Xiangfeng’s team introduced the preparation method of a new type of chiral molecule intercalated superlattice material . By inserting layers of chiral molecules into the gaps of van der Waals materials, also known as intercalation, a "superlattice" material is formed, consisting of alternating two-dimensional atomic monolayers and highly ordered layers of chiral molecules. highly ordered superlattice structure and chiral optical selection properties . This superlattice material, in the chirality-induced spin selectivity, solves the problem of low structural uniformity in previous solid-state devices resulting in low spin selectivity in large areas of the sample. This research also designed and processed a spin tunneling connection device , using the prepared chiral molecule intercalated superlattice material as a spin filter layer, achieving a tunnel magnetoresistance ratio of more than 300% and a tunnel magnetoresistance ratio of more than 60%. Spin polarizability. This study provides a platform for exploring chirality-induced spin selectivity in solid-state devices and offers broad prospects for future chiral molecular electronic devices.
Thermal insulation ceramic aerogels under extreme conditions
In the second study, Harbin Institute of Technology Professor Xu Xiang , Professor Li Hui and the University of California, Los Angeles Professor Duan Xiangfeng team again after Science Collaborating with , multi-scale designed and synthesized subcrystalline zirconium nanofibers aerogel with a zigzag structure, achieving excellent thermomechanical properties with close-to-zero Poisson's ratio and close-to-zero thermal expansion coefficient performance. The resulting ceramic aerogel has high mechanical flexibility, high thermal stability under severe thermal shock and high temperature, and excellent high-temperature insulation properties. exhibits excellent mechanical flexibility under repeated cyclic compression 1,000 times at a strain of 50% with almost no stress degradation and a bending strain of up to 90% without any external fracture failure. The ceramic aerogels can also achieve twist angles up to 360° with little morphological change or structural degradation under cyclic loading, demonstrating excellent fatigue resistance. At the same time, it retains its original shape after 10,000 thermal shock cycles, with ultimate stress remaining almost unchanged and strength degradation barely exceeding 1%, indicating excellent structural stability and resistance to severe temperature cycles.In addition, the thermal conductivity is only 26 mW m-1K-1 at 25 °C and only 104 mW m-1K-1 at 1,000 °C, demonstrating excellent high-temperature insulation properties for extreme conditions. Providing reliable thermal insulation materials for a variety of applications, especially in the aerospace field.
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https://www.nature.com/articles/s41586-022-04846-3
https://www.nature.com/articles/s41586-022-04784-0
Source: Frontiers of Polymer Science
