Scanning electron microscopy zinc oxide

Scanning electron microscopy shows the cement to consist of zinc oxide particles embedded in an amorphous matrix (Smith, 1982a). As with the zinc phosphate cement, a separate globular water phase exists since the cement becomes uniformly porous on dehydration. Porosity diminishes as the water content is decreased. Wilson, Paddon Crisp (1979) distinguish between two types of water in dental cements non-evaporable (tightly bound) and evaporable (loosely bound). They found, in the example they examined, that the ratio of tightly bound to loosely bound water was 0-22 1-0, the lowest for all dental cements. They considered that loosely bound water acted as a plasticizer and weakened the cement. 

Zinc Oxide. Scanning electron microscopy (SEM) of the ZnO particles synthesized using 20% O2 in He at a total pressure of 800 torr and a top plate temperature of -100 has indicated that the particle diameters are typically between 10 and 20 nm. The particle size is sensitive to the temperature gradient used in the experiment. For example, by setting the condensation plate (top plate) temperature at -40OC, the average particle size was found to be 50-60 nm. 

Abstract The scope of this work consisted of precipitating directly zinc oxide particles from zinc nitrate and zinc sulphate solutions using sodium hydroxide at pH 10,5, 2 h and 25 or 60 °C. For the zinc nitrate system, the effect of additives at 25 °C, such as sodium sulphate and sodium dodecyl sulphate, was also investigated. Precipitated powders were characterized in terms of their crystalline structure (X-ray diffraction), morphology and size (scanning electron microscopy, transmission electron microscopy). Precipitation in distilled water with zinc nitrate produced homogeneous star-type particles (1 /rm) composed of assembled 30-nm crystallites at 25 °C and ellipsoidal and spherical particles (100 nm to 1 fim) at 60 °C. On the other hand, for the zinc sulphate system at 25 °C, several different morphologies were obtained as ellipsoids (250 x 800 nm),... 

The role of silica-only systems on adhesion has been studied using model compounds with squalene [59]. It was shown that the mechanism for increased adhesion to brass-coated wire-to-rubber was not just a simple improvement of the physical properties of the rubber, but that silica moderated the thickness and composition of the interfacial layer by a chemical interaction. SEM-EDX (scanning electron microscopy with energy dispersive analysis of X-rays), XPS, AES and PIXE (proton induced X-ray emission spectroscopy) revealed that silica affected the relative concentrations of compounds present in the interfacial layer, promoting zinc oxide formation in particular. 

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