Staining agents

One of the main uses of osmium tetroxide is as a biological staining agent for microscopic ceU and tissue studies. Osmium tetroxide is unique in that it both fixes and stains biological material. 

Since 1980, mthenium tetroxide, RuO, has been used for staining a number of heterophase polymers for tern (221) it seems to be a more versatile staining agent than OsO. For instance, in SAN modified with acrylate mbber, where the mbber phase is fully saturated, an excellent contrast between the mbber and the matrix has been achieved (222). Crystalline polymers have been stained with RuO (223), and excellent cra2e stmctures have been revealed (221). The stain may be prepared by dissolving RuCl - 3H2O in aqueous sodium hypochlorite for immediate use (224). 

The Rf for this adduct is 0.6 in CH2CI2. Its presence is clearly visible when anisaldehyde is employed as the staining agent. 

PVF exhibits excellent resistance to weathering, outstanding mechanical properties, inertness toward a wide variety of chemicals, solvents, and staining agents, excellent hydrolytic stability, and high dielectric strength and dielectric constant.94... 

The most common staining agents are aqueous solutions (co. 2 wt% concentration)... 

Molecular model of picric acid. Picric acid (2,4,6-trinitrophenol) is a close relative of trinitrotoluene (TNT). It is an explosive compound and has military applications. Picric acid has also been used as a yellow dye and staining agent and as an antiseptic. 

Table 4.2 Polymer Functional Groups and Staining Agents...

Some electron micrographs were taken of PA/EPDM blends (5 wt. % PA) using 0s0, as a staining agent for the polyacetylene phase. As shown In Figure 1, the polyacetylene phase appears to be discontinuous, while the elastomeric EPDM material forms the continuous matrix. Exposure of the films to I2 vapor for 24 hours resulted in ultimate conductivities of 10 - 90 Jl-1 cm-1, depending upon polyacetylene contents. It... 

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