Elasticity electron microscopy

Nylon-6. Nylon-6—clay nanometer composites using montmorillonite clay intercalated with 12-aminolauric acid have been produced (37,38). When mixed with S-caprolactam and polymerized at 100°C for 30 min, a nylon clay—hybrid (NCH) was produced. Transmission electron microscopy (tern) and x-ray diffraction of the NCH confirm both the intercalation and molecular level of mixing between the two phases. The benefits of such materials over ordinary nylon-6 or nonmolecularly mixed, clay-reinforced nylon-6 include increased heat distortion temperature, elastic modulus, tensile strength, and dynamic elastic modulus throughout the —150 to 250°C temperature range. 

The other striking feature of nanotubes is their extreme stiffness and mechanical strength. Such tubes can be bent to small radii and eventually buckled into extreme shapes which in any other material would be irreversible, but here are still in the elastic domain. This phenomenon has been both imaged by electron microscopy and simulated by molecular dynamics by lijima et al. (1996). Brittle and ductile behaviour of nanotubes in tension is examined by simulation (because of the impossibility of testing directly) by Nardelli et al. (1998). Hopes of exploiting the remarkable strength of nanotubes may be defeated by the difficulty of joining them to each other and to any other material. 

If the sample is thin enough, for example a specially prepared thin section, electrons may go straight through and be detected, as well as elastically and inelastically scattered electrons which are scattered in a forward direction. These form the basis of transmission electron microscopy (TEM). 

Under the conditions of Example 5-23 the rubber phase of the end product shows an interesting micro-morphology. It consists of particles of 1-3 microns diameter into which polystyrene spheres with much lower diameters are dispersed. These included polystyrene spheres act as hard fillers and raise the elastic modulus of polybutadiene. As a consequence, HIPS with this micro-morphology has a higher impact resistance without loosing too much in stiffness and hardness. This special morphology can be visualized with transmission electron microscopy. A relevant TEM-picture obtained from a thin cut after straining with osmium tetroxide is shown in Sect. 2.3.4.14. 

Analytical electron microscopy is the most sophisticated tool available for micro-structural analysis today. In this method, we can obtain both the high-resolution structure and elemental composition of a specimen. This is probably the best technique to obtain local elemental composition of small regions of heterogeneous solids. When a high-energy electron beam is incident on a specimen, we get elastically and inelastically... 

An example of such order is shown by the hexagonal symmetry of SBS as revealed by LAXD, electron microscopy and mechanical measurements. In composite materials the choice of phase is at the disposal of the material designer and the phase lattice and phase geometry may be chosen to optimise desired properties of the material. The reinforcing phase is usually regarded elastically as an inclusion in a matrix of the material to be reinforced. In most cases the inclusions do not occupy exactly periodic positions in the host phase so that quasi-hexagonal or quasi-cubic structure is obtained rather than, as in the copolymers, a nearly perfect ordered structure. 

The human erythrocyte possesses a characteristic biconcave shape and remarkable viscoelastic properties. Electron microscopy studies performed on red blood cells (RBC), ghosts, and skeletons revealed a two-dimensional lattice of cytoskeletal proteins. This meshwork of proteins was thought to determine the elastic properties of the RBC. This... 

Sherratt, M. J., Holmes, D. F., Shuttleworth, C. A., and Kielty, C. M. (1997). Scanning transmission electron microscopy mass analysis of fibrillin-containing microfibrils from foetal elastic tissues. Int. J. Biochem. Cell Biol. 29, 1063-1070. 

Macroscopically, elastin appears to be an amorphous mass. Ultrastruc-tural electron microscopy studies reveal that elastin has a fibrillar substructure comprised of parallel-aligned 5nm thick filaments that appear to have a twisted ropelike structure (Gotte et al., 1974 Pasquali-Ronchetti et al, 1998). A variety of techniques have been used to resolve these filaments, including negative staining electron microscopy of sonicated fragments of purified elastic fibers (Serafini-Fracassini et al., 1976), freeze... 

Van den Bergh, B.A., et al. 1999. Interactions of elastic and rigid vesicles with human skin in vitro Electron microscopy and two-photon excitation microscopy. Biochim Biophys Acta 1461 155. 

Recently, a four-laboratory cooperative study has led to a comparison of the determination of particle size distribution by electron microscopy, quasi-elastic light scattering and wide angle light scattering (20). 

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