Bright field and dark field STEM‐IN‐SEM imaging of polymer systems

Abstract

The microstructural analysis of polymer systems (e.g., polymers and their composites) has largely been conducted by transmission electron microscopy (TEM). However, hard materials (e.g., metals and ceramics) are better suited for TEM imaging because such materials can withstand the high energy electron beam generated in TEM instruments. Recently, scanning TEM in scanning electron microscopy (STEM-IN-SEM) has emerged as a viable alternative to TEM imaging of polymer systems. STEM-IN-SEM uses a versatile and user-friendly SEM instrument for examining the microstructure of polymer systems. In this study, we outline our method for STEM-IN-SEM imaging and apply it to the imaging of various commercial and model polymer systems. Imaging results are evaluated on the basis of measured signal intensity, which compare favorably to microstructural analysis using more costly TEM and STEM instruments. Furthermore, these comparable signal intensities are achieved through STEM-IN-SEM imaging with specimens that are three times thicker than those required for conventional TEM imaging. In this respect, as compared to TEM, STEM-IN-SEM offers faster specimen preparation times coupled with easier usability and lower maintenance costs, which are all attractive attributes for efficient quality control measures in industry.

In Situ Self‐Assembly of Ultrastable Crosslinked Luminescent Gold Nanoparticle and Organic Dye Nanohybrids toward Ultrasensitive and Reversible Ratiometric Thermal Imaging

“…To study the morphology and structure of the AuNP–BBS nanohybrids, a series of characterization techniques were used, including transmission electron microscopy (TEM), bright field scanning transmission electron microscopy in scanning electron microscopy (BF‐STEM‐in‐SEM), and dynamic light scattering (DLS) (Figure c,d; Figures S4 and S5, Supporting Information). TEM image demonstrated that the AuNP–BBS nanohybrids consisted of about ten crosslinked uniform spherical AuNPs with a core size of 2.1 ± 0.5 nm, and the size of the nanohybrids formed by these crosslinked ultrasmall AuNPs was measured to be 13.1 ± 2.4 nm, which was smaller than the results obtained by BF‐STEM‐in‐SEM (18.9 ± 2.6 nm) and DLS (20.0 ± 6.0 nm) due to the presence of poly(ethylene glycol) (PEG) chains on the surface.…”