Surfaces energy attributed

The TEM images of the starch-capped ZnSe nanoparticles showed that the particles were well dispersed, small and spherical in shape. The particles are in the range 2.3 to 4.2 nm with mean particle diameter of 3.3 nm and standard deviation (o) of 0.562 nm indicating broad size distribution. The TEM diameter is in accordance with the XRD result. The broad size distribution was attributed to the aggregation of the smaller particles which are thermodynamically unstable in the solution as a result of their high surface energy which makes them very reactive (Wei et al., 2004 Lee at al., 2002, 2003). 

The blends, irrespective of the concentration of fluororubber, show surface energy lower than neat rubbers. This is attributed to the migration of silicone mbber to the surface. The presence of silicone rubber on the surface of the blends also contributes to their lower limited oxygen index compared to that of fluoroelastomers. 

Our experience indicates that fluorination generally results in decreased adhesion strength compared to oxyfluorination (see Tables 16.6 and 16.8). This is in contrast to reported findings in the literature where epoxy adhesives were used.7,29 This discrepancy can be attributed to the surface energy implications of the increased acyl fluoride to the C—H—F functionalkation ratio (compare Figures 16.3 and 16.4). However, as indicated by our data, certain resin formula-... 

The methods of measurement of the surface energy of liquids may be divided into two classes the static and dynamic methods. In general for pure unassociated liquids in contact with their vapour alone the values of the surface energy determined by the two methods do not differ beyond the range which may be attributed to experimental error. In other cases, however, marked divergence between the values obtained by the two methods is to be noted. This divergence is, as we shall have occasion to note, due to the comparatively slow rate of attainment by diffusion of equilibrium in the surface phase of solutions. 

Siloxane elastomers present an attractive alternative to the butadiene acrylonitrile elastomers most often used for epoxy modification. Poly(dimethyl siloxanes) exhibit glass transition temperatures well below those of butadiene acrylonitrile modifiers (minimum —123 °C vs. about —40 °C) and also display very good thermal stability13, 14). Other favorable and potentially useful attributes include good weatherability, oxidative stability, and moisture resistance. Finally, the non-polar nature and low surface energy of poly(dimethyl siloxanes) constitute a thermodynamic driving force... 

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