Periodic Reporting for period 1 - SuprAtom (Boosting Cation Exchange in Self-Assembled Supraparticles through Advanced Electron Tomography Techniques)
Période du rapport: 2020-04-01 au 2022-03-31
The motivation of the project is to establish a robust route to structuring multicomponent colloidal self-assemblies in a controllable manner. Compared to single component SPs, it is still challenging to design multicomponent SPs as the parameter space to achieve the optimum thermodynamics and kinetic effects is large. Therefore, a new synthesis approach is required. In this project, one of the objectives was to develop methodology, mostly focusing on synthesis multicomponent supraparticles using cation exchange (CE) on already formed colloidal self-assemblies. By controlling the CE reactions, one can synthesize hierarchical superstructures with controllable compositions on multiple length scales. Such structure can eventually have great potential as photocatalysts and photovoltaics due to the ability to control their optoelectronic properties via their tuneable composition and structure. In order to understand why and how the hierarchical multi-component supraparticles form, a robust advanced characterization toolbox needs to be urgently developed. Especially, to track the structure and composition structures in real conditions becomes to be crucial.
During this project, I developed different types of colloidal self-assemblies by using the slowly drying emulsion droplets method, forming the so-called supraparticles, including CdSe, FeMnZn/CdSe, and FeCoO/CdSe supraparticles containing anisotropic/isotropic building blocks, which are not trivial to realize before. Performing cation exchange on supraparticles lead to even more complex hierarchical superstructure , which otherwise cannot be achieved via conventional self-assembly routines. The emergence of multi-component colloidal supraparticles further expanded the library of hierarchical colloids, but also provided ideal experimental platform for the study of formation and driving forces of soft condense matter. By teaming up the EMAT research team, I developed high-throughput in-situ liquid tomography and fast tomography techniques for supraparticles. Advanced electron tomographic reconstructions procedures have been established. Quantitative and qualitative comparison between conventional and high-throughput tomography validated reliability of new acquisition, alignment, and reconstruction. During this project, I was invited to give talks regarding my research in conference and symposium.
The abovementioned research progress not only deliver new fundamental understanding on colloidal self-assembly on multiple length scales, but the results are also expected to yield new insights concerning functionalities of colloidal self-assemblies in potential optoelectronic applications. It is envisaged that the success of making multicomponent supraparticles will bring new opportunities to optoelectronic (nano)devices fabrication and catalysis in the future. Moreover, the research progress pushed the development of advanced transmission electron microscopy techniques to a new limit. Specifically, a novel data tomography data acquisition scheme and a reconstruction method for large, compact colloidal self-assemblies has been established. The development of in-situ tomography technique allows to study the structure of colloidal assemblies in their native (real) environment.