Three dimensional-transmission electron microscopy

Imaging the mesopores in zeolite Y using three-dimensional transmission electron microscopy... 

Crystalline phases (truncated octahedra) of 5 nm silver particles, thiolate protected as well, have been detected by means of high-resolution transmission electron microscopy (HRTEM) [26-28]. Three-dimensional architectures of 5-6 nm thiolate-stabilized gold particles have also been described [29]. Several other reports on 3D superlattices of metal nanoparticles have become known during the last few years [30-33]. 

Transmission electron microscopy (TEM) can provide valuable information on particle size, shape, and structure, as well as on the presence of different types of colloidal structures within the dispersion. As a complication, however, all electron microscopic techniques applicable for solid lipid nanoparticles require more or less sophisticated specimen preparation procedures that may lead to artifacts. Considerable experience is often necessary to distinguish these artifacts from real structures and to decide whether the structures observed are representative of the sample. Moreover, most TEM techniques can give only a two-dimensional projection of the three-dimensional objects under investigation. Because it may be difficult to conclude the shape of the original object from electron micrographs, additional information derived from complementary characterization methods is often very helpful for the interpretation of electron microscopic data. 

Fig. 2. Nacre of red abalone shell Halitotis refescens), imaged here by transmission electron microscopy (left), has a bricks-and-mortar structure. The bricks are CaCOs (aragonite) platelets, and the mortar is a composite of macromolecules, including structural proteins and polysaccharides, that form a thin film around the platelets. The three-dimensional structure is depicted on the right [23]...

TEM transmission electron microscopy UHV ultra high vacuum 3D three dimensional... 

Several different gelation measurement methods have been described in the literature, particularly differential scanning calorimetry (DSC), capillary rheometry, transmission electron microscopy (TEM) and atomic force microscopy (AFM). The gelation level is characterised either by crystallinity related aspects or factors that relate to the development of the three-dimensional network and the corresponding disappearance of the particulate structure (465, a.l). 

Transmission, freeze-fracture, and scanning electron microscopy have contributed ultrastmctural information about passive transport, particularly within the stratum comeum. Advances in fixation protocols for transmission electron microscopy have preserved the intercellular bilayers of the SC and have corrobrated their role in both passive and enhanced dmg delivery. Scanning and freeze-fracture electron microscopy have supplemented transmission electron microscopy by supplying three-dimensional representations of the transport pathways within the SC. 

The aim of this work is to relate the resistance towards compression of silica materials to the morphological characteristic which suits elementary particle or the aggregate. By elementary particle, we mean the smallest homogeneous entity visible by transmission electron microscopy and by aggregate, we mean the filaments constituted of elementary particles which build up the three-dimensional network of the material. The behaviour of three silica materials with elementary particles similar in size was compared when submitted to mercury isostatic pressure. In the three methods for obtaining those materials, the size of the silica particles can be tailored. They differ by the presence or absence of aggregation or by... 

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