Irregular replicas

With FRFE we differentiale the existence of regular and irregular replicas. A regular fractional replica is obtained from a FUFE matrix by dividing it into a number of parts divisible by two (2, 4, 6, 8, 16, etc.). The obtained replicas are respectively marked by 1/2-replica or half-replica, 1/4-replica, 1/8-replica, etc. Irregular replicas are obtained by taking, for example 3/4 and 5/8 of the FUFE matrix. 

Catalyst structure may be studied by numerous and widely varying methods. Apart from the crystallographic pattern, the structure of the outer surface or of the surface layers is especially important. Unfortunately, we do not know much about the real structure of the surface. It is an important question to know to what degree the surface is a two-dimensional replica of the three-dimensional regularities and irregularities of the lattice. 

Figure 11. Replicas of a4ead azide surfaces showing the development, on heating, of lead on the surface. There is little evidence for discrete lead nuclei, the irregular circular features on the (010) plane being characteristic of undecomposed material [61] (X6500).

By contrast, PPO is not compatible with chlorinated PS, either poly(p-chlorostyrene)(PpClS) or poly(o-chlorostyrene)(PoClS) (6). Blends of PPO with either PpClS or PoClS form opaque films and exhibit two glass transitions identical in temperature and dispersion width to those of the corresponding unblended polymers. The independence of phase Tg on blend composition (weight fraction PPO) for PpClS/PPO blends is illustrated in Fig. 1. In addition, fracture replicas of PpCIS/PPO blends indicate macroscopic phase separation of the component polymers into large irregular-shaped domains(7). 

Figs. 11 and 12 show the surfaces and edges of a 600 pim and a 120 p.m wide Fe7.cross-section for small ribbons. The irregular edges are clearly visible in the upper half of Fig. 11 (air side of ribbon) and the air inclusions in the lower half (wheel side of ribbon). For the smaller ribbons (Fig. 12) the surface tension becomes more important. It rounds and smoothens the surface on the air side (Fig. 13), whereas the smaller width allows the air drawn with the wheel to flow around the liquid droplet. The. surface of the small ribbon (lower half of Fig. 12) shows essentially a replica of the Cu-wheel surface. Fig. 14 shows the quantitative surface profiles of the two ribbons shown in Figs. 11 and 12. Here again it becomes evident that the impressions produced by the air inclusions penetrate more than 5 p.m into the interior. This amounts to not less than 10 to 20% of the total thickne.ss. 

Figure 2. Microscopic structure of the inverse replica SEM a) granule structure b) regular inverse replica structure c) irregularities within the inverse replica.

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