Direct Imaging of the Crystalline Domains and Their Orientation in the PS-<i>b</i>-PEO Block Copolymer with 4D-STEM
Min Chen, Karen C. Bustillo, Vivaan Patel, Benjamin H. Savitzky, Hadas Sternlicht, Jacqueline A. Maslyn, Whitney S. Loo, Jim Ciston, Colin Ophus, Xi Jiang, Nitash P. Balsara, Andrew M. Minor
Abstract
High Resolution Image Download MS PowerPoint Slide The arrangement of crystalline domains in semicrystalline polymers is key to understanding how to optimize the nanostructured morphology for enabling better properties. For example, in polystyrene- b -poly(ethylene oxide) (PS- b -PEO), the degree of crystallinity and arrangement of the crystallites within the PEO phase plays a crucial role in determining the physical properties of the electrolyte. Here, we used four-dimensional scanning transmission electron microscopy to directly visualize the crystal domains within the PEO-rich region of the PS- b -PEO block copolymer and show the relative angle of the domain with respect to the PEO–PS interface. As demonstrated here, our analysis method is applicable to other electron-beam sensitive materials, especially semicrystalline polymers, to unveil their local phase condition and distribution.