Double striations

Sintering TE-3170 at a higher temperature, 380 °C, for 5 min (Fig. 24a) results in some rearrangement and partial merger of the particles, including the development of double striations on some of them (inset). A thin film similar to that in Fig. 22a (350 °C, 5 min) surrounds each cluster of particles. The... 

In the main portion of Fig. 25b, of sintered resin G, individual double stria-tions grow out from the dispersion particles that were held at 350 °C for 1 h. As shown in the lower-right inset, the rod particles may serve as epitaxial nuclei for the double-striations which then can continue growth on the substrate. The doubled nature of the striations is seen most clearly when they are on the particles. In the lower-center inset (380 °C, 2 h) two double striations are present on and extending from the particle it is not known whether the particle is a short rod or an ellipsoid. At the center of the micrograph and in the center-... 

As shown by Fig. 27c, NaCl appears to serve as a nucleating agent as well as an epitaxial substrate. Double striations are nucleated at the surface, growing out perpendicular, as well as being oriented on the surface parallel to the faces. In this case there even seems to be some climbing of the molecules up and over the NaCl surface. 

Figure 28a and b contains micrographs of two samples of Ausimont nanoemulsion held at 380 °C for 20 and 30 min, respectively, before slow cooling in the press. In Fig. 28a the ends of large, well-developed bands are seen, each with numerous double striations each has a total width of approximately... 

After 10 min of sintering (Fig. 50c) many of the kebabs contain several double striations and are more randomly oriented relative to the shish core (which,... 

The double-striations in TE-5070 samples (Figs. 30, 31a) and A18749 (Fig. 28a) appear to grow up from (or on) parallel narrow lamellae. 

The double-striation morphology has tentatively been attributed to Pt nucleation on the fold edges of on-edge lamellae, similar to Au nucle-ation on the fold edges or interlamellar regions of, e.g., on-edge lamellae in drawn, annealed films of polyoxymethylene [37] and epitaxially crystallized samples of various other polymers [38]. AFM is currently being used to characterize further this feature. 

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