Spray cross-sectional structures

FIGURE 1.14 Cross-sectional structures of spray-dried powders by CLSM. Wall materials MD (DE 2 and 20). 

In the last decade confocal laser scanning microscopy (CLSM) was shown to be a helpful tool for various further tasks of microparticle characterization (Lamprecht et al., 2000a, b, c). It minimizes the light scattered from out-of-focus structures, and permits the identification of several compounds through use of different fluorescence labels. Therefore, CLSM can be applied as a non-destructive visualization technique for microparticles. Moreover, CLSM allows visualization and characterization of structures not only on the surface, but also inside the particles, provided the carrier matrices are sufficiently transparent and can be fluorescently labeled by collecting several coplanar cross-sections, a three-dimensional reconstruction of the inspected objects is possible. Figure 6.13 shows the application of CLSM to investigatation of the cross-sectional structures of spray-dried powders of maltodextrin (MD) with a dextrose equivalent value of DE = 2 and 20. Florescein sodium salt was dissolved in the feed solution as a fluorescent probe of the carrier... 

Figure 5.33 shows the surface (a) and the cross section (b) of a typical HVSF-sprayed hydroxyapatite coating with a highly dense structure that attest to complete melting of the powder particles and superior adhering to the substrate. The dense coating resembles a glassy layer with non-identifiable lamella boundaries (see also Bolelli et al., 2014). 

The hollow ATO-PANI spheres obtained via the Pickering approach were decorated by Pt nanoparticles using a standardized polyol process. The chosen synthesis protocol for Pt decoration used mild conditions, which hence did not impact the hollow sphere structure. The hollow spheres were then sprayed onto a commercial Nation membrane and applied at the cathode side of an MEA. Figure 7.14a depicts a cross-sectional SEM image of the oxidic hollow spheres. It can be clearly observed that the sphere structure is maintained after the polyol process for Pt decoration. Single cell tests of the novel electrode design showed a maximum power density of 58 mW cm and a platinum utilization... 

Figure 6 (A) Cross-section of a TBC deposited by air plasma spraying (APS). The plate-like structure is evident in the coating shown by the inset figure, the bond coat is NiCoCrAlY fabricated by low pressure plasma spraying (LPPS) (B) Cross-section of a TBC deposited by electron beam physical vapom deposition (EBPVD) on a Pt-enriched y+y bond coat. Note the coliunnar microstructure of the coating.

The cross section in Figure 15 shows the temporary support structure for a proposed excavation about 30 m deep and 29 m wide. The retaining structure consisted of a soldier pile wall with sheetpiles driven as deep as possible between the soldier piles. If the sheetpiles did not penetrate to formation level, it was proposed to spray concrete on the exposed face between the soldier piles. Each level of excavation was expected to take 30 to 60 days. 

Fig. 28.11 TEM cross-section micrographs of SnO films deposited by spray pyrolysis (a) grained structure, T =330-350 °C, d=10-80 nm (b, c) columnar structure, (b) T =475 °C, d=300 nm, (c) T =510 °C, d=75-100 nm (iCeprinted with permission from Korotcenkov et al. 2005b, Copyright 2005 Elsevier)...

In 1984, Tran [73] reported the first use of SERS identification and detection of structurally similar dyes for TLC. The separation paper was prepared for SERS detection by spraying the TLC paper with silver hydrosols after the paper had been spotted by the analyte or by adding the silver hydrosols and analyte together in a premixed solution to the paper. As noted in another 1984 publication by Tran [89], the detection levels of dyes corresponded well with their molar absortivity, thus giving a possible a priori means of determining detection limits of unstudied dyes. In this article, detection limits for various dyes varied from 0.500 to 240 ng, but only a 3-mW He-Ne laser was used for Raman excitation. Such low laser power was possible because approximately a 9-10 order-of-magnitude increase in Raman cross sections occurs as a result of the surface-enhanced effect. In addition, Rau [42] has shown the use of near-IR excitation with SERS, which further eliminates the possibility of fluorescence problems arising in TLC experiments. 

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