Transmission electron microscopy , gold

Determined by inductively coupled plasma-mass spectrometry of acid digested catalyst samples Calculated from X-ray diffraction peak broadening at (101) foranatase and (110) formtile TiOa Mean particle diameter measured from transmission electron microscopy pictures of gold catalysts... 

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]. 

Lastly, gold supported on Mg(OH)2 is very active for CO oxidation even at 200 K [30]. However, it suddenly died after 4 months. Transmission electron microscopy could not clarify the reason because no appreciable change in particle diameter was observed. X-ray scattering due to gold clusters was measured experimentally. The... 

Complexation of gold ions, [Au(I)], with peripheral phosphine groups of a P-based dendrimer was reported by Majoral et al. [185]. Transmission electron microscopy (TEM) was used to analyze the large aggregates formed by the dendritic gold complexes and a direct correlation was observed between the size of the particles and the dendrimer generation number. In a recent report [186], Majoral et al. further demonstrated that up to 48 diphosphino groups could be anchored to the surface of dendrimers and various dendritic metal-complexes... 

Study by Transmission Electron Microscopy Tomography of gold nanoparticles in reduced Au/zeolites... 

Tomography was applied during Transmission Electron Microscopy (TEM) analysis of various reduced Au/zeolite samples. The size and location of the gold nanoparticles as a function of the support characteristics and preparation method are discussed. 

The polymer resulting from oxidation of 3,5-dimethyl aniline with palladium was also studied by transmission electron microscopy (Mallick et al. 2005). As it turned out, the polymer was formed in nanofibers. During oxidative polymerization, palladium ions were reduced and formed palladium metal. The generated metal was uniformly dispersed between the polymer nanofibers as nanoparticles of 2 mm size. So, Mallick et al. (2005) achieved a polymer- metal intimate composite material. This work should be juxtaposed to an observation by Newman and Blanchard (2006) that reaction between 4-aminophenol and hydrogen tetrachloroaurate leads to polyaniline (bearing hydroxyl groups) and metallic gold as nanoparticles. Such metal nanoparticles can well be of importance in the field of sensors, catalysis, and electronics with improved performance. 

Spherical gold nanoparticles coated with poly(N-isopropylacrylamide) (PNIPAM) grafts have been synthesized by controlled radical polymerization. The polymerization of N-isopropylacrylamide was initiated from the surface of the nanoparticles modified with 4-cyanopentanoic acid dithiobenzoate for reversible addition-fragmentation chain-transfer polymerization. The mean diameter of the Au core was 3.2 nm, as observed by means of high-resolution transmission electron microscopy [90]. 

Fig. 4 Transmission electron microscopy of a longitudinal section of the posterior end of a Cryptosporidium parvum sporozoite showing immunogold localization of pyruvate NADP+ oxidoreductase (CpPNO). The mitochondrion-like organelle ( ) is posterior to the nucleus, and lies between the nucleus and the CB. It is labeled by mitochondrion-specific 15-nm gold anti- particles. Small -nm gold goat anti-CpPFO particles (arrows) show the localization of CpPNO. There are no 6-nm particles localized within the mitochondrion-like organelle (reprinted from Fig. 12 of Ctrnacta et al. 2006 with permission of the publishers)...

Horisberger, M., Rosset, J. and Vonlanthen, M. 1977. Location of glycoproteins on milk fat globule membrane by scanning and transmission electron microscopy, using lectin-labelled gold granules. Exp. Cell Res. 109, 361-369. 

Fig. 7.7 Scanning transmission electron microscopy (STEM) images of supported gold catalysts, along with particle diameter distributions, double-logarithmic plots showing how particle volume (proportional to intensity) depends on particle size, and geometric distributions of truncated octahedrons with certain edge lengths and thickness, as indicated in Figure 7.8. (Adapted from [18]).

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