Scanning electron micrograph complexes

The next two examples illustrate more complex surface reaction chemistry that brings about the covalent immobilization of bioactive species such as enzymes and catecholamines. Poly [bis (phenoxy)-phosphazene] (compound 1 ) can be used to coat particles of porous alumina with a high-surface-area film of the polymer (23). A scanning electron micrograph of the surface of a coated particle is shown in Fig. 3. The polymer surface is then nitrated and the arylnitro groups reduced to arylamino units. These then provided reactive sites for the immobilization of enzymes, as shown in Scheme III. 

Fig. 6.2 Scanning electron micrograph of a Cui.2Se film deposited from a selenosul-phate solution of complexed with nitrilotriacetate.

Because of the obvious complexity of the controlling factors that may be involved, we shall not attempt at present to estimate their functional magnitude. The existence of interconnecting channels was postulated from scanning electron micrographs of bioleached shale surface (II) and is supported by evidence from the present study. The increase of porosity by removing the carbonate mineral with dilute acid would presumably improve the permeability of certain chemical compounds into and out of the remaining shale structure. 

Figure 11. Scanning electron micrograph of a freshly fractured sample of complexed nylon 66 showing the distorted layers corresponding to Figure 7. Sample was unshadowed and fractured at liquid nitrogen temperature.

Unfortunately the surface of the complexed sample cannot be replicated and examined by electron microscopy because the solvents normally used perturb the complex by introducing artifacts. However scanning electron micrographs of these fracture surfaces indicate that the morphology of the original polymer is modified considerably by the I2-KI treatment—a fact consistent with the wide angle x-ray and other evidence. It has been pointed out elsewhere (11) that thin films and fibers of complexed polyamides are very pliable and often putty-like when first removed from the complexing solution this fact is consistent... 

Figure 2. Scanning electron micrographs (at three magnifications) of a fire flood emulsion illustrating a case in which, although the water-oil ratio is 2.5 1, water is the dispersed phase. The composition of this emulsion is 63% water, 11% solids, and 26% oil. The compositions of the dispersed and continuous phases were determined from the X-ray signal excited in the electron microscope. The size of the dispersed water phase ranges from less than 0.1 pm up to about 10 pm. The large features labeled O are regions of oil phase that can be described as oil emulsified in a continuous phase of a water-in-oil emulsion. These complex systems are difficult to characterize with anything but microscopic methods.

Figure 13. Scanning electron micrograph of transverse section of air-dried Picea sp. from a 1200 A.D. Thule site Herschel Island. The fractured surface shows oil-swollen secondary cell walls of latewood tracheids separated from the primary wall complex. This is shown in detail in Figure 14. The earlywood tracheids appear normal.

Figure 3-3. Fiber was oxidized, reduced, and then extended to fracture in the dry state. This scanning electron micrograph was taken at the fracture site. Note the multiple-step fractures and that much of the fracturing occurs in the cell membrane complex. SEM kindly provided by Sigrid Ruetsch of Textile Research Institute/ Princeton.

Figure 3-6. Fiber reduced with thioglycolic acid at pH 10 and extended to break in the dry state. Note the cracks between the scales caused by a weakened cell membrane complex. Scanning electron micrograph kindly provided by Sigrid Ruetsch of Textile Research Institute/Princeton.

Figure 48. Representative scanning electron micrographs of the LB films of (a) Lig, (b) Lig after 12 months, (c) Cu(ll) inclusion complex of Lig, and (d) Cu(ll) inclusion complex of Lig after 12 months exposed to air.

Scanning electron micrograph of a [Chi(HAP)/PAA]2 bilayer film with the hydroxyapatite nanoparticles, which are interwoven in the multilayer architecture and complexed to chitosan (g) IR absorbance spectra of the different components of the osteoconductive layer (i) chitosan, (ii) hydroxyapatite, (iii) poly(acrylic acid), (iv) [Chitosan/HAP]j, (v) [Chitosan/ PAA]j , and (vi) [Chi(HAP)/PAA] . 

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