Transmission Electron Microscopy and Dynamic Light Scattering-Fundamental Perspective (original) (raw)
Related papers
Characterization of nanomaterials with transmission electron microscopy
IOP Conference Series: Materials Science and Engineering, 2016
The field of nanotechnology is about research and development on materials whose at least one dimension is in the range of 1 to 100 nanometers. In recent years, the research activity for developing nano-materials has grown exponentially owing to the fact that they offer better solutions to the challenges faced by various fields such as energy, food, and environment. In this paper, the importance of transmission electron microscopy (TEM) based techniques is demonstrated for investigating the properties of nano-materials. Specifically the nano-materials that are investigated in this report include gold nano-particles (Au-NPs), silver atom-clusters (Ag-ACs), tantalum single-atoms (Ta-SAs), carbon materials functionalized with iron cobalt (Fe-Co) NPs and titania (TiO 2) NPs, and platinum loaded Ceria (Pt-CeO 2) Nano composite. TEM techniques that are employed to investigate nano-materials include aberration corrected bright-field TEM (BF-TEM), high-angle dark-field scanning TEM (HAADF-STEM), electron energy-loss spectroscopy (EELS), and BF-TEM electron tomography (ET). With the help presented of results in this report, it is proved herein that as many TEM techniques as available in a given instrument are essential for a comprehensive nano-scale analysis of nanomaterials.
Scientific reports, 2015
Standard transmission electron microscopy nanoparticle sample preparation generally requires the complete removal of the suspending liquid. Drying often introduces artifacts, which can obscure the state of the dispersion prior to drying and preclude automated image analysis typically used to obtain number-weighted particle size distribution. Here we present a straightforward protocol for prevention of the onset of drying artifacts, thereby allowing the preservation of in-situ colloidal features of nanoparticles during TEM sample preparation. This is achieved by adding a suitable macromolecular agent to the suspension. Both research- and economically-relevant particles with high polydispersity and/or shape anisotropy are easily characterized following our approach (http://bsa.bionanomaterials.ch), which allows for rapid and quantitative classification in terms of dimensionality and size: features that are major targets of European Union recommendations and legislation.
Transmission Electron Microscopy of Nanomaterials
Electron Crystallography
Structural and analytical characterization, in the nanometer scale, has become very important for all types of materials in recent years. Transmission electron microscope (TEM) is a perfect instrument for this purpose, which is summarized in this chapter. Parameters such as particle size, grain size, lattice type, morphological information, crystallographic details, chemical composition, phase-type, and distribution can be obtained by transmission electron micrographs. Electron diffraction patterns of nanomaterials are also used to acquire quantitative information containing size, phase identification, orientation relationship and crystal defects in the lattice structure, etc. In this chapter, typical electron diffraction, highresolution transmission and scanning transmission electron microscope imaging in materials research, especially in the study of nanoscience are presented.
Transmission electron microscopic imaging of nanomaterials
2015
This procedure aims to record a set of calibrated transmission electron micrographs showing NM that are representative for the NM on the EM grid. The number of particles and the magnification of the micrographs are suitable for subsequent descriptive and quantitative image analyses.
The core contribution of transmission electron microscopy to functional nanomaterials engineering
Research on nanomaterials and nanostructured materials is burgeoning because their numerous and versatile applications contribute to solve societal needs in the domain of medicine, energy, environment and STICs. Optimizing their properties requires in-depth analysis of their structural, morphological and chemical features at the nanoscale. In a transmission electron microscope (TEM), combining tomography with electron energy loss spectroscopy and high-magnification imaging in high-angle annular dark-field mode provides access to all features of the same object. Today, TEM experiments in three dimensions are paramount to solve tough structural problems associated with nanoscale matter. This approach allowed a thorough morphological description of silica fibers. Moreover, quantitative analysis of the mesoporous network of binary metal oxide prepared by template-assisted spray-drying was performed, and the homogeneity of amino functionalized metal-organic frameworks was assessed. Besides, the morphology and internal structure of metal phosphide nanoparticles was deciphered, providing a milestone for understanding phase segregation at the nanoscale. By extrapolating to larger classes of materials, from soft matter to hard metals and/or ceramics, this approach allows probing small volumes and uncovering materials characteristics and properties at two or three dimensions. Altogether, this feature article aims at providing (nano)materials scientists with a representative set of examples that illustrates the capabilities of modern TEM and tomography, which can be transposed to their own research.
Scanning Transmission Electron Microscopy Methods for the Analysis of Nanoparticles
Methods in molecular biology, 2012
Here we review the scanning transmission electron microscopy (STEM) characterization technique and STEM imaging methods. We describe applications of STEM for studying inorganic nanoparticles, and other uses of STEM in biological and health sciences and discuss how to interpret STEM results. The STEM imaging mode has certain bene fi ts compared with the broad-beam illumination mode; the main advantage is the collection of the information about the specimen using a high angular annular dark fi eld (HAADF) detector, in which the images registered have different levels of contrast related to the chemical composition of the sample. Another advantage of its use in the analysis of biological samples is its contrast for thick stained sections, since HAADF images of samples with thickness of 100-120 nm have notoriously better contrast than those obtained by other techniques. Combining the HAADF-STEM imaging with the new aberration correction era, the STEM technique reaches a direct way to imaging the atomistic structure and composition of nanostructures at a sub-angstrom resolution. Thus, alloying in metallic nanoparticles is directly resolved at atomic scale by the HAADF-STEM imaging, and the comparison of the STEM images with results from simulations gives a very powerful way of analysis of structure and composition. The use of X-ray energy dispersive spectroscopy attached to the electron microscope for STEM mode is also described. In issues where characterization at the atomic scale of the interaction between metallic nanoparticles and biological systems is needed, all the associated techniques to STEM become powerful tools for the best understanding on how to use these particles in biomedical applications.
Nanoparticle shape and configuration analysis by transmission electron tomography
Journal of Microscopy, 2008
Tomographic reconstruction by transmission electron microscopy is used to reveal three-dimensional nanoparticle shapes and the stacking configurations of nanoparticle ensembles. Reconstructions are generated from bright-field image tilt series, with a sample tilt range up to ± 70 • , using single or dual tilt axes. We demonstrate the feasibility of this technique for the analysis of nanomaterials, using appropriate acquisition conditions. Tomography reveals both cubic and hexagonal close-packing configurations in multi-layered arrays of size-selected In nanospheres. By tomography and phase-contrast lattice imaging, we relate the three-dimensional shape of PbSe octahedral nanoparticles to the underlying crystal structure. We also confirm simplecubic packing in multi-layers of PbSe nanocubes and see evidence that the particle shapes have cubic symmetry. The shapes of TiO 2 nanorod bundles are shown by tomographic reconstruction to resemble flattened ellipsoids.