Electron microscopy sputter coating

This technique can be applied to samples prepared for study by scanning electron microscopy (SEM). When subject to impact by electrons, atoms emit characteristic X-ray line spectra, which are almost completely independent of the physical or chemical state of the specimen (Reed, 1973). To analyse samples, they are prepared as required for SEM, that is they are mounted on an appropriate holder, sputter coated to provide an electrically conductive surface, generally using gold, and then examined under high vacuum. The electron beam is focussed to impinge upon a selected spot on the surface of the specimen and the resulting X-ray spectrum is analysed. 

Scanning electron microscopy (SEM) seems to have been used only scarcely for the characterization of solid lipid-based nanoparticles [104], This method, however, is routinely applied for the morphological investigation of solid hpid microparticles (e.g., to smdy their shape and surface structure also with respect to alterations in contact with release media) [24,38,39,41,42,80,105]. For investigation, the microparticles are usually dried, and their surface has to be coated with a conductive layer, commonly by sputtering with gold. Unlike TEM, in SEM the specimen is scanned point by point with the electron beam, and secondary electrons that are emitted by the sample surface on irradiation with the electron beam are detected. In this way, a three-dimensional impression of the structures in the sample, or of their surface, respectively, is obtained. 

Scanning Electron Microscopy, An ISI model Super II (International Scientific Instruments Inc., Milpitas, CA) scanning electron microscope was used for morphology study (Labtech, Fairfield, NJ). Powder was properly loaded on specimen stub via a double stick tape. Samples were coated with 60% gold and 40% palladium for 6 min at 100 to 200 mtorr in a sputter coater. 

Microscopy. Scanning electron microscopy was run on resin samples using a AMR 1200 Scanning Electron Microscope. The samples were mounted on the stub using double stick tape and then sputter coated with gold. 

Samples of microspheres were mounted on aluminum specimen mounts by means of double-faced tapes. The microspheres were fractured with razor blades to expose the internal matrix. The samples were then coated with approximately 125 of gold by pulsing the sputter coater to avoid the possibility of artifact caused by heat generation. Secondary emissive scanning electron microscopy was performed with an Amray 1600 Turbo scanning electron microscope. 

Morphology. The morphology of the fracture surface of the two-phase epoxy thermosets was examined by scanning electron microscopy (SEM, Amray model 1000B). SEM specimens were sputter-coated with a thin film of gold. 

Field Emission Scanning Elecfron Microscopy (FE-SEM) was performed in order to study the product morphologies of the samples. The aforementioned silica samples, which were suspended in water, were centrifuged (r. p. m. = 13400) and washed with ethanol. They were then placed on SEM sample holders and dried. The dried silica samples were sputter coated with gold and were then analyzed under the electron microscope. 

The surface morphology of modified PU sheets was examined with a Hitachi S-510 scanning electron microscopy (SEM) at an accelerating voltage of 15 kV. Samples were mounted and then sputter-coated with gold using an ion coater. 

Tensile bond strength (TBS) were determined using a testing protocol and assembly previously described (6). To assess the efficacy of smear layer removal by aqueous AA the surface of 1 mm thick dentin cross sections were pretreated with one drop (0.05 mL) of AA (17.6 wt. % in distilled HjO pH = 2.0). The durations of AA treatment were 15, 30, 45, 60, and 120 s. l ch AA treated dentin surface was rinsed with distilled water for 10 s and then was air dried. The dentin specimens were then sputter coated with gold for evaluation by scanning electron microscopy (SEM). 

Yoon et al. used Palladium (Pd) to modify Nafion membranes by coating them with a different thickness of Pd film, using as puttering method (Yoon et al. 2002). The scanning electron microscopy (SEM) micrographs showed that the 10 and 30 nm Pd films were dense and appeared to be well attached to the membrane. However, some cracks were found on the surface of the 100 nm Pd film. It was believed that the cracks were caused by the difference between the Nafion membrane and the Pd film in the expansion that took place when the composite membrane was immersed in water. The Nafion membrane swells more than the Pd film, which eventually develops cracks in the Pd film. Therefore, the sputtering procedures for a membrane thicker than 100 nm apparently need to be improved. From this research, a trade-off between proton conductivity and methanol crossover was noted similar to the results... 

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