Faculty Host: Allison Dennis
Faculty Host: Alex Saeboe
Refreshments at 2:45 PM
Title: Self-assembly of Anisotropic Nanocrystals from Periodic Superlattices to Aperiodic Quasicrystals
Nanocrystal quantum dots have been widely studied for decades. Continuous optimizations in synthesis have allowed production of high-quality quantum dots with exquisitely controlled size, shape and compositions. These high-quality quantum dots can be used as building 'bricks' for constructing higher-order architectures. While building assemblies from isotropic particles has been well studied and documented, creating novel superstructures from complicated and anisotropic building blocks still lags significantly behind. Anisotropic nanocrystals with defined composition, shape and surface patchiness represent a unique class of building objects for constructing high-order architectural nanomaterials. When utilizing in assembly, anisotropic nanocrystals can display strong asymmetric interactions induced by the patchiness that may complicate the formation of ordered structures compared to the assemblies of isotropic building blocks. In this talk, I will use several types of anisotropic 'patchy' nanocrystals as examples to demonstrate how they assemble into the unprecedented superstructures through the directional interactions among the building blocks under an enthalpy-driven condition. Both translational periodicities and orientational ordering of the final superstructural materials will be discussed. The dominating driving forces lead to the obtained architectures will be identified through molecular dynamics computer simulations and experimental results.
Ou Chen is an assistant professor in the Department of Chemistry at the Brown University. He received his BS degree in Chemical Physics from the University of Science and Technology of China (USTC) in 2004, and completed his PhD study in the Department of Chemistry at the University of Florida. He was working with Prof. Moungi Bawendi as postdoctoral associate at MIT before joining Brown University in 2015. Prof. Ou Chen has so far published more than 50 publications in high-impact journals (total citation of ~ 4200 and H-index of 29). He is currently appointed as a Young Star Editor of Nano Research journal. His current research interests focus on exploring novel methodologies for fabrications of functional nanocrystals, semiconductor quantum dots, perovskite nanomaterials and their self-assembled superstructures for energy, catalysis and bio-related applications.