Metal salts Modification

The modification of Rh/USY with alkali metal salts such as NaOH, NaNOs, Na2C03, NaCl, etc. was, therefore, performed in order to control the strength and number of strong Bronsted acid sites of Rh/USY catalyst. It was revealed that the catalyst deactivation of Rh/USY was remarkably improved by the addition of small amount of alkali metal salts Modification with NaOH was the most effective and 0.5wt% addition of Na using NaOH was optimal amount for the improvement of the catalyst deactivation with reaction time as shown in Figure 4... 

Textile dyes were, until the nineteenth century invention of aniline dyes, derived from biological sources plants or animals, eg, insects or, as in the case of the highly prized classical dyestuff Tyrian purple, a shellfish. Some of these natural dyes are so-caUed vat dyes, eg, indigo and Tyrian purple, in which a chemical modification after binding to the fiber results in the intended color. Some others are direct dyes, eg, walnut sheU and safflower, that can be apphed directly to the fiber. The majority, however, are mordant dyes a metal salt precipitated onto the fiber facUitates the binding of the dyestuff Aluminum, iron, and tin salts ate the most common historical mordants. The color of the dyed textile depends on the mordant used for example, cochineal is crimson when mordanted with aluminum, purple with iron, and scarlet with tin (see Dyes AND DYE INTERMEDIATES). 

Other modifications have special but more limited apphcations. A centrifugal bowl may contain, instead of disks, several aimular baffles that take the hquid through a labyrinth path before discharge. The multiple cylinders increase cake capacity to as much as 70 L for easily sedimented sohds. This centrifuge is used for clarification of food symps and antibiotics (qv), and for recovery of heavy metallic salts and catalysts (see Fig. 14c). 

Biomass is generally made up of polymers, oligomers, monomers, and other nonpolymerizable simple organic compounds, including metallic salts and complexes [17,29,30]. Polymers are, of course, the major components and have been serving human civilizations from time immemorial. The literature on natural polymers is vast and only a few reviews and books are cited here for further reference [3,17,18,24,29-31,37-53]. The outstanding aspect of natural polymers is their wide variety, which provides innumerable opportunities for structural modifications and utilization. 

To improve the dimensional stability of the oligoethyleneoxy phosphazene/ metal salt complexes, some attempts have been reported which concern the chemical modification of the parent polymers, their chemical or radiation cross-linking, or the use of blends. 

A novel, electrochemically assisted method of obtaining semiconductor quantum dots supported on a surface has been introduced by Penner and his group [123], It comprised a hybrid electrochemical/chemical (E/C) process consisting of electrochemical deposition followed by chemical modification and it was described as a general, rapid, and low-cost solution-phase method for synthesizing supported Q-dots of metal salts. 

Crisp, S., Merson, S. A. Wilson, A. D. (1980). Modification of ionomer cements by the addition of simple metal salts. Industrial Engineering Chemistry, Product Research Development, 19, 403-8. 

The third composition in Table IV seems to be related to the aromatic sulfonate/polycarbonate technology just discussed with some modifications being necessary in order to compensate for the aliphatic nature of the polypropylene (17. 181 substrate. In this case the aromatic sulfonate is replaced with a metal salt (preferably magnesium stearate). A silicone oil and or gum has been added to enhance the intumescent character and a small amount of inert filler and decabromodiphenyl oxide is included probably to improve the molding characteristics of the total composition. Fire retardant compositions with a good surface char can be obtained at total loadings only about half that required for the halogen/antimony oxide composition. 

It was previously mentioned was that a large number of minor copolymers of PET have been developed over the past 50 years, with the intent of modifying textile fiber properties and processability [2, 3], Of broader interest is that some of these textile modifications, such as PET copolymers with metal salts of 5-sulfoisophthalic acid (SIPA), have their own rich chemistries when the extent of polymer modification is increased beyond textile levels. An example of such a modification is that changing the counterions associated with SIPA can significantly effect the kinetics of polyester transesterification reactions (the... 

This procedure is a modification of preparations of 3-phen)d, sydnone described earlier. The dehydration of N-nitroso-N phenylglycine has also been effected by the use of thionyl chloride and pyridine in dioxane, thionyl chloride in ethertrifluoroacetic anhydride in etherand diisopropylcarbodiimide in water or by reaction of the alkali metal salts of N-nitroso-N-phenylglycine with phosgene or benzenesulfonyl chloride in water or with acetyl chloride in benzene. ... 

The synthesis and structural aspects of metal salts of NTO, that is, K, Cu and Pb NTO reveal that they have special characteristics and may find applications in several fields including ballistic modification of rocket propellants. The study of their thermal behavior with differential scanning calorimetry (DSC) suggests that ... 

This last compound also prevent the penetration of metal salts in the depth of the polymer. Otherwise, other authors such as Janssen et al. [153, 154] investigated the chemical modification of polydimethylsiloxane to prepare materials used in the medical field. Hence, they modified the wettability of PDMS by a treatment of surfaces with ozone followed by UV decomposi-... 

The species to be compared are loaded in 6% Ficoll (w/v) onto an 8% or 10% polyacrylamide gel with 29 1 monomer bisacrylamide. We generally use 90 mM Tris—borate (pH 8.3) buffer containing either EDTA or added metal salts. Electrophoresis is typically performed for 1—2 days at 5 V/cm at room temperature. When salts are included in the electrophoresis buffer, this must be recirculated between the cathodic and anodic reservoirs at a rate of 1 L/h. This may require a little modification of commercial gel electrophoresis apparatus. Our RNA species generally include at least one strand that is radioactively [5/-32P] -labeled. When the electrophoresis is complete the gel is dried onto Whatman 3MM paper and exposed to storage phosphor plates at 4 °C followed by phosphorimaging to provide a gel image. 

Boric acid ester salts can be formed by reacting alcohols (including diols) with boric acid in the presence of alkaline metal salts. The surface modification of poly(vinyl alcohol) and poly(ethylene-co-vinyl alcohol) with boric acid and sodium hydroxide leads to... 

To the extent to which mechanisms have been proposed to account for the catalytic effect of some metal salts in dehydrochlorination (e.g., by Troitskaya and Troitskii (27)), the removal of H and Cl from adjacent carbon atoms on the same chain is generally postulated. Such mechanisms, with little modification, could as easily explain crosslinking. Cross-linking will, of course, occur without metal catalysts, but the rate is much slower. 

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