Scanning electron microscopy coating

For the purpose of calibration and particle size calculations, it was decided to confirm the reported particle sizes of the various latices supplied by Dow and Polysciences, using scanning electron microscopy. Unfortunately, after subtracting the thickness of the gold layer with which the particles were coated from the size shown on the micrographs, some inconsistencies were noted with respect to the measured sizes of the particles and their elution behaviour. It was therefore decided to assume the reported sizes as true values with the exception of the 5T nm particle. 

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. 

Figure 3. Scanning electron microscopy images of gold electrodes coated by the nanostructured TMPP/C12 monolayer after the electrochemical platinum deposition. The deposition charge was 41 and 160Cm for the left and right images, respectively. (Reprinted from Ref [18], 2005, with permission from Wiley-VCH.)...

II. Scanning electron microscopy of radish seeds For scanning electron microscopy (SEM) observations, seed coats and endosperms were fixed in 3% glutaraldehyde in 0.065 M phosphate buffer (pH 7.4) for 2 h at... 

Fig. 5. Scanning electron microscopy picture of a tungsten tip coated with Apiezon wax. Only the foremost 10 pm of the tip or less remain uncoated.

The overlays thickness estimation is possible exploiting a twin fiber placed in the same deposition chamber and subject to the same coating procedure. The coated twin fiber can be cut by a precision cleaver and analyzed by scanning electron microscopy (SEM). One of the deposited thin overlay is clearly observable in the SEM image of the fiber section reported in Fig. 3.13. 

Figure 4.11 Scanning electron microscopy images of bare and coated magnesium chips. Clear morphological differences are seen between the coated and uncoated samples. (Reproduced from ref. 13, with permission.)...

Bishop, J.H., Silva, S.R. The examination of the structure of antifouling coatings by scanning electron microscopy. JOCCA, 52 (1969) 201-218. 

The scanning electron microscopy micrographs shown in the body of this manuscript were taken by AMR-1000 and Jeol C-35 instruments. All specimens were gold-palladium coated. To obtain the cross-section morphologies, the membranes were fragmented in liquid nitrogen. 

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