Transmission electron microscopy cast thin films

Conformation and structure of A-block in solid state Infrared spectra of solid films of the samples cast from solution were measured with a Shimazu Modjl-30 A IR spectrophotometer in a region of 4000 to 400 cm. X-ray diagrams were obtained by using Ni-filtered Cu Ka radiation, setting a flat surface of the film parallel to a reflecting surface with an automatic diffractometer. For the electron microscopy measurement, thin films cast from solution were stained with osmium tetroxide and examined by transmission microscopy. 

In transmission electron microscopy (TEM), a beam of highly focused and highly energetic electrons is directed toward a thin sample (< 200 nm) which might be prepared from solution as thin film (often cast on water) or by cryocutting of a solid sample. The incident electrons interact with the atoms in the sample, producing characteristic radiation. Information is obtained from both deflected and nondeflected transmitted electrons, backscattered and secondary electrons, and emitted photons. 

Morphology of select star blocks was investigated by transmission electron microscopy (TEM). Films were cast from toluene and annealed for 2 days at 120 °C. Ultra thin sections (-50 nm) of unstained samples were cut by cryogenic microtome techniques. Samples were viewed by a JOEL (JEM-1200EXII) TEM. 

Demonstier-Champagne et al. used atomic force microscopy (AFM) to observe microphase separation within cast films of PS-PMPS-PS/ PS-PMPS block copolymer mixtnre [43] that were nsed to compatibilize a blend of PMPS and PS. The fractnre snrface of blend films with the block copolymer incorporated show a far finer dispersion of particle sizes than those without. Matyjaszewski et al. studied PMPS-PS thin films by SFM (scanning force microscopy) and TEM (transmission electron microscopy) and Fig. 8 shows a TEM picture of a thin section of a film which was prepared by slow evaporation from THE, which is slightly selective for the polystyrene block [73]. 

TEM Characterization of the Particle Size in Thin Films cast from the Colloidal Solutions Because the UVA is spectra did not give direct evidence on the particle size, transmission electron microscopy was done on thin films which had been casted fi om the micellar solution. It has been demonstrated recently that the micellar structures can be well preserved when a block ionomer solution is evaporated to yield a solid film (77,75). 

Figure 26 Electron micrographs, (a) Transmission electron microscopy of a thin film of poly(26d)-ib/oc/r-polyisoprene-i /oc/c-poly(26d) cast from methyl isobutyl ketone (MIBK) (b) scanning electron microscopy (SEM) of the surface of cross-linked microporous membrane (c) SEM of cross section of cross-linked microporous membrane.

Our research on these subjects began more than 25 years ago with Yeh s examination of the morphology and properties of amorphous poly(ethylene terephthalate) (PET) and the effect thereon of crystallization and deformation. Both thick and thin (i.e., > 10 i and ca. 1,000 A, suitable for transmission electron microscopy) samples were used, the samples being either quenched from the melt or cast from solution into the amorphous state. The films, as prepared, were amorphous by x-ray or electron diffraction. 

The ESCR performance of a resin is not easily modeled. A laboratory technique for the preparation of thin films of HIPS materials for the study of deformation processes by microscopy allows the deformation process to be better understood. The transmission electron microscope (TEM) allows direct visualization of the crazes themselves in thin films. For good contrast between the crazes and the bulk polystyrene, thin, cast films from 0.5 to 2 p,m are required, and also staining of the rubber phase with a heavy atomic species to provide contrast between the rubber and the polystyrene. Another intricacy of this method requires a solution of the HIPS material in a 65 35 methyl ethyl ketone-toluene solution to prevent significant swelling of the rubber particles during the preparation process. 

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