TEM measurements

The earliest observations of carbon nanotubes with very small (nanometer) diameters [151, 158, 159] are shown in Fig. 14. Here we see results of high resolution transmission electron microscopy (TEM) measurements, providing evidence for m-long multi-layer carbon nanotubes, with cross-sections showing several concentric coaxial nanotubes and a hollow core. One nanotube has... 

Fig. 10. Scanning electron microscope (SEM) image of the probe with an MWCNT attached to a silicon cantilever [35]. Protruding of one individual MWCNT has been confirmed by transmission electron microscope (TEM) measurement (not shown here).

D-TEM was introduced into rubber technology field in 2004 by the authors of this chapter [4]. In a recent review of 3D-TEM applied in materials science field [5], only two papers were cited on polymeric samples—one on block copolymers [6] and the other on rubbery composites with conventional and in situ silica [4]. Starting from the latter, 3D-TEM measurements have been carried out on rubbery nano-composites [7-16], and this recent and very important topic is described in this review. 

FIGURE 19.2 Procedure for three-dimensional-transmission electron microscopic (3D-TEM) observation, composed of TEM measurements and computerized tomography to reconstruct a 3D image. (From Kohjiya, S., Kato, A., Shimanuki, J., Hasegawa, T., and Ikeda, Y., Polymer, 46, 4440, 2005. With permission.)... 

Figure 7. Optical absorption spectra of Au-implanted silica samples atmealed in air (a) or Ar (b) for 1 h at different temperatures, (c) Nonlinear fit (empty circles) to the optical absorption spectrum of the sample annealed at 900 °C in air, from which the average cluster diameter is obtained and compared to the TEM measured one, (d) Evolution of the optical spectra of Au-...

After supporting these sols on activated carbon, however, the obtained particle size depends on the capability of the protective agent to maintain the particle dimension. The obtained three catalysts, having different characteristics, are summarized in Table 3. As it is shown, mean size of gold nanoparticle obtained by TEM measurement did not always match with X-ray powder diffraction (XRPD) data. This result is not surprising as TEM measurements represent particle sizes, whereas from X-ray diffraction (XRD) it is possible to obtain crystallite dimensions that do not necessarily coincide with the size of... 

Fig. 13.9 Transmission electron microscopic data ofendocytosis. Saos-2 cell was treated with LDH and after 1 h the cell was fixed and subjected to TEM measurement. (A) successive internalization of LDH via endocytosis access of LDH around plasma membrane, formation of membrane ruffles and interaction...

Sc(naphthenate)3/ROH/AlR3 (1/2/7) has been found to exhibit an activity similar to the lanthanide series catalyst [114], The cis PA film obtained with it showed an electrical conductivity of 14.4 S cm 1 when the polymer was doped with I2 at a ratio of (CHI0.04)n, and the TEM measurement suggested the formation of ca. 20-30 nm fibrils. 

TEM measurements revealed clustering of aggregates in all cases except for PS-de dr-(COOH)8 for which individual worm-like micelles were observed. 

J. Kappler, N. Birsan, U. Weimar, A. Dieguez, J.L. Alay, A. Romano-Rodriguez, J.R. Morante, and W. Gopel. Correlation between XPS, Raman and TEM measurements and the gas sensitivity of Pt and Pd doped Sn02 based gas sensors Fresenius Journal of Analytical Chemistry 361 (1998), 110-114. 

It is difficult to evaluate the shape of such dendritic particles experimentally. However, some insight can be gained by atomic force microscopy (AFM) and transmission electron microscopy experiments (TEM). AFM experiments can give information about the overall size of the dendrimers, as shown by De Schryver [43], by spincoating very dilute solutions of dendrimers like 30 on mica, then visualizing single dendrimers. Their height measured in this manner corresponds very well to the diameters calculated by molecular mechanics simulations. First results from TEM measurements also confirm the expected dimensions [44]. Unfortunately, due to resolution limits, up to now direct visual information could not be obtained about the shape of the dendrimers. 

Since the x-ray fiber diffraction measurements based on citrus pectin (32) were consistent with the TEM measurements of tobacco pectin, we prepared a gel from citrus pectin similar to the previous x-ray sample. This gel was then examined by TEM. Air-dried samples of this gel, shown in Figure 5, demonstrated long stretches of helix in the molecules lying on the surface. (In the freeze-dried gels—not shown—only short stretches of helix were visible.) The average filament width in the air-dried gel was found to be 14.2A. After correcting for the added size due to the Pt/C coating... 

Concern arises regarding the disagreement between the fiber width determined by TEM measurement and the theoretically calculated size for fibrils made of a single... 

So far, we have prepared and tested many kinds of colloids, mainly in nonaqueous suspensions with combinations of metals or alloys as a dispersed phase and organic liquids as the dispersion media, without the use of any dispersing agents these are listed in Table 9.4.1. We next give some examples of transmission electron micrographs of nanoparticles produced by an aerosol method. A sample for TEM measurement was obtained by dropping colloidal suspension onto a Cu mesh coated with an evaporated carbon film of 10 nm thickness. Many colloids were so unstable... 

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