This research combines the development of a novel microscopy technique, transmission scanning electron microscopy (T-SEM) with the synthesis and characterization of novel, nanostructured materials for water treatment and sustainable energy applications. T-SEM involves the use of a traditional SEM chamber in transmission mode (electrons that pass through the sample are detected, similar to TEM/STEM) at much lower electron beam energies as compared to traditional TEM. The lower beam energies allow imaging and analysis of beam-sensitive samples, such as nanoparticles and polymeric or biological materials. In addition, T-SEM can be used to determine not only material morphology but material phase and composition. The technique is particularly amenable to the analysis of composite, nanostructured, and/or functionalized materials, and therefore holds great promise for unprecedented levels of characterization of nanomaterials now under consideration for both water treatment and sustainable energy applications. Because many other techniques require dry, high vacuum environments, the structure and composition of the nanomaterial limits our understanding of the resultant properties in such applications. We are interested in the development of in situ measurement techniques involving liquid cells in the T-SEM for measurement of nanoparticles, polymeric membranes, and composite particle-polymer membranes and films, all targeting water- and energy applications. Both theoretical and experimental work are needed to understand and implement liquid cell imaging in the T-SEM, including studies of image formation, contrast mechanisms, resolution, and limits of both static and dynamic data collection. Our laboratory has a field emission scanning electron microscope with an automated electron backscatter diffraction system, energy dispersive spectrometer, transmission detectors (secondary conversion and ADF/BF) for the SEM, and specimen preparation facilities. We also have state-of-the-art nanomaterial synthesis capabilities.

 

key words

Biological materials; Electron microscopy; Membranes; Nanoparticles; Nanotechnology; SEM; STEM; TEM;

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral applicants