Understanding Nanoparticle Crystallization, Aggregation and Dissolution Using Advanced In Situ TEM Techniques

The investigation of nanoparticle crystallization, aggregation, and dissolution processes is critical for advancing technologies in catalysis, environmental remediation, and energy storage. Recent studies show that these processes often deviate from classical crystallization models, necessitating detailed analysis of particle interactions and structural evolution at the nanoscale. In this work, we present our research utilizing advanced in situ transmission electron microscopy (TEM) techniques to observe nanoparticle crystallization, aggregation, and dissolution in real-time. By combining in situ environmental TEM-AFM, we directly measure the interaction forces between nanoparticles, providing valuable insights into their aggregation mechanisms and interfacial dynamics. Furthermore, in situ liquid cell TEM is employed to investigate the formation mechanisms of gibbsite (α-Al(OH)₃) mesocrystals and to elucidate the dissolution behavior of akaganeite (β-FeOOH) under various environmental conditions. These studies reveal how particle aggregation, oriented attachment, and dissolution evolve within complex systems, offering new perspectives on the non-classical pathways that govern nanoparticle transformations. Our findings contribute to the development of improved strategies for controlling material properties in a wide range of technological applications.