Phosphorus encapsulated

Red phosphorus has been used as an effective PBT FR, is non-halogen-based, and very high in active ingredient [55, 56], However, red phosphorus melt blending requires some special considerations. The potential generation of phosphine gas and acidic decomposition products under incorrect melt processing conditions is a concern. Recently, encapsulated grades of red phosphorus have minimized some of these potential issues. Red P blends are also limited in color capability. 

A completely different arrangement of the six metal atoms is present in the phosphide monoanion [Os6(CO)i8P]. In fact, Figure 49 shows that the phosphorus atom is completely encapsulated in a trigonal-prismatic metal cage. 

Carbon and Phosphorus Burial Efficiencies. The estimate of diatom carbon demand (12-15 g/m2 per year) is consistent with the flux of carbon to the sediment surface. With sediment-trap fluxes corrected for resuspension, we measured a total annual deposition flux of 12.5 g of C/m2. In comparison, Eadie et al. (24) obtained 23 g of C/m2 for a 100-m station, based on three midsummer metalimnion deployments. Of our total, 83% of the carbon was associated with diatoms, and the primary diatom carbon flux was 10.3 g of C/m2. Thus, about 15-30% of the diatom carbon was regenerated in the water column during sedimentation. Approximately 10% of the diatom flux reached the sediment surface encapsulated in copepod fecal pellets the remaining 90% was unpackaged. 

For the sake of completeness the ultimate, encapsulated phosphorus ligand in [Rh9(CO)21P]2 is described.327 Like [Co2(CO)5(PPh3)(P2)], [Rh CO P]2- is formed by stripping the substituents from a tertiary phosphine ligand in tetraethyleneglycol dimethyl ether solution (equation 97). 

When phosphorus is added to Si02, in addition to gettering mobile alkali ions, it tends to reduce the intrinsic tensile stress in such films, thereby reducing their tendency to crack. Both functions are important when the film is used as a final passivation film for integrated circuits encapsulated in plastic. Phosphorus additions of 7 weight percent seem to be optimum in order to produce the above desirable film characteristics. 

Although atomic nitrogen and phosphorus are usually very reactive species, upon encapsulation they do not react with C60 while their electrons possess a long-lived spin. That spin can play the role of a natural quantum information unit with its two states up and down similar to the classical 1 and 0 states. Going one step further, because of the shielding by C60 the qubit in the fullerene... 

There is much interest in transition-metal carbonyl clusters containing interstitial (or semi-interstitial) atoms in view of the fact that insertion of the encapsulated atom inside the metallic cage increases the number of valence electrons but leaves the molecular geometry essentially unperturbed. The clusters are generally anionic, and the most common interstitial heteroatoms are carbon, nitrogen, and phosphorus. Some representative examples are displayed in Fig. 19.4.3. 

Red phosphorus will react with atmospheric moisture to form toxic phosphine gas and will ignite readily in air. As a result, the commercial product is often encapsulated in an appropriate polymer matrix. Suitable stabilization and encapsulation have led to commercial concentrates containing 50% red phosphorus. Handling hazards and the color of the final flame-retardant products may be a deterrent for wider use. 

A suspension of nutshell particles in DMF was quatemized with tributyl-phosphine. This converted the encapsulated poly(VBC) into poly[(vinylben-zyl)-tributylphosphonium chloride]. The EDS experiments indicated a low surface concentration of phosphorus in the quaternized samples. Since the elemental analysis indicated a high content of phosphorus in all the samples, one can infer that the quaternary onium cations are hidden inside the polystyrene cages . 

Metal-phosphorus (As and S) carbides (see Table 2) are prepared by long-term sintering of encapsulated pressed powder pellets, but TijSC can also be obtained by extraction from the proper steels. 

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