Observing the Growth of Metal–Organic Frameworks by <i>in Situ</i> Liquid Cell Transmission Electron Microscopy Joseph P. Patterson Patricia Abellan Michael S. Denny Chiwoo Park Nigel D. Browning Seth M. Cohen James E. Evans Nathan C. Gianneschi 10.1021/jacs.5b00817.s008 https://acs.figshare.com/articles/media/Observing_the_Growth_of_Metal_Organic_Frameworks_by_i_in_Situ_i_Liquid_Cell_Transmission_Electron_Microscopy/2157841 Liquid cell transmission electron microscopy (LCTEM) can provide direct observations of solution-phase nanoscale materials, and holds great promise as a tool for monitoring dynamic self-assembled nanomaterials. Control over particle behavior within the liquid cell, and under electron beam irradiation, is of paramount importance for this technique to contribute to our understanding of chemistry and materials science at the nanoscale. However, this type of control has not been demonstrated for complex, organic macromolecular materials, which form the basis for all biological systems and all of polymer science, and encompass important classes of advanced porous materials. Here we show that by controlling the liquid cell membrane surface chemistry and electron beam conditions, the dynamics and growth of metal–organic frameworks (MOFs) can be observed. Our results demonstrate that hybrid organic/inorganic beam-sensitive materials can be analyzed with LCTEM and, at least in the case of ZIF-8 dynamics, the results correlate with observations from bulk growth or other standard synthetic conditions. Furthermore, we show that LCTEM can be used to better understand how changes to synthetic conditions result in changes to particle size. We anticipate that direct, nanoscale imaging by LCTEM of MOF nucleation and growth mechanisms may provide insight into controlled MOF crystal morphology, domain composition, and processes influencing defect formation. 2015-06-17 00:00:00 dynamic bulk growth defect formation materials science MOF crystal morphology growth mechanisms ZIF conditions result electron beam irradiation polymer science Situ Liquid Cell Transmission Electron MicroscopyLiquid cell transmission electron microscopy cell membrane surface chemistry nanoscale imaging electron beam conditions domain composition LCTEM particle size MOF nucleation particle behavior