Transmission electron microscopy resin sections

Figure 5.40. Transmission electron microscopy thin section of phosphotungstic acid stained cryosections of an as extruded (A) and deep drawn (B) coextruded film constructed of toughened nylon/barrier resin/tough-ened nylon. (From Wood [186] used with permission of the American Chemical Society Rubber Division.)...

High Resolution Transmission Electron Microscopy (HRTEM, Philips CM20, 200 kV) was applied to get structural and nanotextural information on the fibers, by imaging the profile of the aromatic carbon layers in the 002-lattice fringe mode. A carbon fiber coated with pyrolytic carbon was incorporated in epoxy resin and a transverse section obtained by ultramicrotomy was deposited on a holey carbon film. An in-house made image analysis procedure was used to get quantitative data on the composite. 

III. Transmission electron microscopy of radish seeds Transmission electron microscopy (TEM) of radish seeds was done as listed below For TEM preparations, the specimens after fixation and dehydration, were embedded in Epon 812 resin (Luft, 1961). Thick sections (ca. 1mm each) were stained with 0.1% toluidine blue and observed with a Zeiss light photomicroscope. Thin sections, obtained with a diamond knife on a Supernova microtome, were sequentially stained at room temperature with 2% uranyle acetate (aqueous) for 5 min and by lead citrate for 10 min (Reynolds, 1963). Ultrastructural studies were made using a Philips CM12 transmission electrone microscope (TEM) operated at 80 KV. 

Transmission Electron Microscopy Transmission electron microscopy data were obtained by personnel in the Ultrastructure Laboratory at the Virginia-Maryland College of Veterinary Medicine using a JEOL lOOCX-II transmission electron microscope. Samples were imbedded in Poly-bed 812 epoxy resin and cured at 50-60°C for 2-3 days. Samples were then sectioned to between 800 and 1000 on either a Sorval MT2B or an LKB IV Ultramicrotome using glass knives and were placed on 200 mesh copper grids. 

TEM (Transmission Electron Microscopy) analysis. This analysis was done on a Philips 420T microscope (120kV, maximum resolution 5A) equipped with an EDAX PV9900 EDS. The catalysts were ground to a powder, embedded in epoxy resin and then microtomed with a diamond l fe to obtain sections about 300A thick. Images were taken at 100 kV. Diameters of about 100 isometric-shaped Pt crystallites were measured for each sample. 

Samples for transmission electron microscopy were prepared in the following manner. A 50/50 blend was potted in an acrylic resin (London Resin Co. Ltd.) and subsequently microtomed in thin films of approximately 600 angstrom thickness and transferred onto electron microscope grids. These sections were then doped with iodine vapor (stained) and were ready for transmission electron microscopy. The blends of other compositions were not examined in this manner for reasons discussed later. 

Transmission electron microscopy (TEM) is important to monitor cell-free sperm decondensation and nuclear formation. To prepare specimens for TEM, incubation mixture aliquots were fixed for 45 min in 2.5% (v/v) paraformaldehyde, 3.1% (v/v) glutaraldehyde, 0.02% (w/v) picric acid in 30 mAf NaHP04, pH 7.5. After fixation, samples were embedded in 2% (w/v) low-gelling-temperature agarose and postfixed for 15 min in 1% (w/v) OSO4. Samples may be dehydrated either in ethanol and propylene oxide or acetone and embedded for sectioning in Spurr s low-viscosity epoxy resin (Spurr, 1%9). Before examination, sections of about 70-nm thickness should be stained, e.g., with uranyl acetate and Reynolds lead citrate (Re)molds, 1%3). 

Transmission electron microscopy (TEM) was utilized to examine the HNT dispersibility within fibrous networks. Because TEM technique generally deals with bulk film samples, fiber mats were embedded into Araldite epoxy resin to prepare fully cured epoxy composites. A 1 x 1 x 1 cm epoxy resin in volume was initially polymerized for 24 h. Subsequently, fiber mats were macerated in epoxy slurry and placed on prepolymerized solid epoxy before the repolymerization of composites. The composite films were sectioned into 100 nm layers using a diamond knife with a Leica EM UC6 microtome, which were further mounted on carbon grids. A JEOL 2011 transmission electron microscope was used at an accelerating voltage of 200 kV to explore the HNT dispersion level within liber mats reinforced epoxy composites. 

Figure 5.91. Transmission electron microscopy cryoultrathin cross sections, cut perpendicular to the melt flow direction and stained with RUO4 vapor, revealed a skin ailment in a molded auto resin part, made with Noryl GTX (A) compared with the same blend near the skin surface (B). (From Wood [52] unpublished.)...

The cross-sections of the coated substrates were also examined by SEM and transmission electron microscopy (TEM). For TEM examination, electron transparent sections were prepared using a Leica Ultracut UCT ultramicrotome. Final sections, of nominal thickness 15 nm, were generated with a diamond knife (Microstar) from the coated alloy that had been encapsulated previously in cured resin, and examined in a JEOL 200FXII transmission electron microscope. 

For transmission electron microscopy (TEM) observations, the membranes were stained with lead or silver ions by ion exchange of the sulfonic acid groups in 0.5 M lead acetate or silver nitrate aqueous solution, rinsed with deionized water, and dried in vacuum oven for 12 h. The stained manbranes were anbedded in epoxy resin, sectioned to 90 nm thickness with Leica Ultracut UCT microtome, and placed on copper grids for TEM. 

Electron microscopy represents the only direct method that permits to see with our own eyes the interior of a sample with a resolution of a few nanometers. To characterize the texture of hypercrosslinked polystyrenes both transmission and scanning electron microscopy have been appfied. In the former case, ultrathin sections with a thickness of about 600 A were cut firom a sample fixed in epoxy resin, and then directly examined in transmission mode. Alternatively, two-step replicas have been prepared firom the cleavage face. To prepare the repfica the surface was first coated with a collodion film appfied from amyl acetate solution, and then with a carbon—platinum film. Finally, the collodion support was dissolved and the free carbon—platinum repfica examined under a transmission microscope. 

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