Center for Functional Nanomaterials Seminar

Self-assembly has spurred a great research interest across different disciplines due to the new fundamental questions it raises as well as the potential for material fabrication. On nanoscale, DNA is a powerful tool allowing the assembly of nanoparticles (NPs) with controlled interparticle distance and specific structural organizations. Synchrotron-based X-ray scattering techniques offer invaluable information to understand the structure and dynamics in such self-assembly systems. In this talk, I will highlight three of my studies, namely, multi-component assembly, dynamic structure control, and NP orientational ordering, as well as demonstrate how to utilize coherent X-ray scattering to advance self-assembly science. First, I will show how to assemble diverse functional NPs into heterogeneous superlattices and elucidate how compositional order, probed by small-angle X-ray scattering (SAXS), can be controlled by the design of DNA shells [1]. Second, I will demonstrate the study of reprogramming DNA interactions to selectively transform the structure of NP superlattices on demand. I will detail how the phase transition pathway is disclosed by pair distribution function (PDF) and different types of SAXS correlation techniques based on real-time in-situ measurements [2]. The third topic is focused on developing SAXS modelling and structural visualization, which helps reveal a remarkable parking with a break of orientational symmetry in nanocube superlattices [3]. Additionally, while working at world-leading coherent hard X-ray scattering (CHX) beamline, I have developed advanced and nearly real-time temporal/spatial-correlation techniques [4], which not only highly benefit the user research programs by also open tremendous new research opportunities (grain boundary dynamics, defects/NP diffusion, strain mapping, crack progradation, etc.) in self-assembly science for the future. The developed techniques could also facilitate the in-situ operando explo