Extractants stability, relation between

All these methods have found applications in theoretical considerations of numerous problems more or less directly related to solvent extraction. The MM calculated structures and strain energies of cobalt(III) amino acid complexes have been related to the experimental distribution of isomers, their thermodynamic stability, and some kinetic data connected with transition state energies [15]. The influence of steric strain upon chelate stability, the preference of metal ions for ligands forming five- and six-membered chelate rings, the conformational isomerism of macrocyclic ligands, and the size-match selectivity were analyzed [16] as well as the relation between ligand structures, coordination stereochemistry, and the thermodynamic properties of TM complexes [17]. 

Bauduin, P., Testard, F., Berthon, L., Zemb, T. 2007. Relation between the hydrophile/ hydrophobe ratio of malonamide extractants and the stability of the organic phase Investigation at high extractant concentrations. The Royal Society of Chemistry. Physical Chemistry Chemical Physics 9(28) 3776-3785. 

RELATION BETWEEN THE FORMULATION OF THE SOLVENT AND THE RADIOLYTIC STABILITY OF THE EXTRACTANT... 

It is assumed here that in every monomer unit there is one point such as P, and that the distance of a single jump is a. However, in certain polymers there may be two identical points such as P in one monomer unit, while in random copolymers PP may not be constant and will depend upon the order of chain growth and the presence of cis- and trans-configurations. A paper published recently [K. Kozlowski, Acta Polymerica, 30, 547 (1979)] deals with ESP studies of uncured carbon black/natural rubber mixes, their solvent extracts, and the residues therefrom. The author found it possible to identify a very narrow spectral line with rubber radicals stabilized by interaction with active sites on the carbon black surface. He concludes that his findings support Meissner s theory (B. Meissner, Rubber Chem. Technol., 48, 810 (1975)] that each structural unit (of the rubber molecule, Z. R.) has the same probability of reaction with the active site of a carbon black particle and can form with it only one bond . The relation between the evidence adduced and Meissner s theory is not, however, clear to the writer... 

Once the functional relation between the electric quantity and the concentration of a gas constituent is well known for a solid/gas system, numerous development steps remain until a sensor can be put to practical use. The determining factor is the goal of application, for example the gas analysis in the laboratory, industrial gas analysis, its use in medical devices or in motor vehicles. In any case, long-term stable physico-chemical systems have to be established which have to fulfill certain conditions. These concern for example the sample extraction and treatment, the temperature, the stability of total pressure and of material qualities, and the construction in a miniature or mechanically and thermally robust form. With solid electrolytes of the same kind one has come across to completely different sensor designs, depending on the application (Figure 25-1). 

Furthermore, extractives determine the pH value due to their solubility, which can often play a role in wood processing. Certain extractives, which can be found for example in larch, oak or various tropical woods, can cause staining or even corrosion when in contact with ferrous materials. In the same way, light resistance or swelling and dimensional stability of the wood can be affected by lipophilic extractives. Furthermore, a relation between certain extractives and the calorific value or even combustion has been reported. ... 

Oil is extracted either by pressing or increasingly by solvent extraction. The crude oil has a strong characteristic flavour and odour and has a dark reddish brown colour. The free fatty acid content of the oil depends on the conditions of harvesting and moisture content of the seed good-quality oil has free fatty acid of 0.5-1%. Normally it is increasingly difficult to bleach the oil satisfactorily as the free fatty add of the crude oil increases. However, there is no direct relation between the quality of the crude oil and the stability and flavour of the fully refined oil. 

A practical means of assessing the stability of the formed bond has been suggested by Sircar and Voet22), who, for various carbon blacks and elastomers, plotted the unextractable amount of rubber from the filler as a function of the temperature of extraction for a variety or solvents. They observed the experimental points related to a given polymer-filler blend to be falling linearly, and the extrapolation to zerografting ratio provided the so-called solvolysis temperature Tm, which appears to be independent of the solvent used. Tm represents the temperature theoretically required to eliminate all bonds between carbon blacks and elastomer and is, therefore,... 

Formally, complexation stability constants in water (log K) and extraction constants (logA j.J can be related via partitioning coefficients of the free ligand and its complex between the aqueous and organic phases.16 However, the latter are rarely available, and therefore the relationships between log/f and log Ktx are not widely used. Nevertheless, in many cases, the binding ability of ligands to metal in complexation and extraction processes follows the same trend. In this respect, information... 

In benzene, Mowah observed some differences between symmetrical amides RCONR2 and unsymmetrical amide RCON(CII3)R. The influence of the dose on >u(vu was stronger for. V-mcthyl-A -alkyl amides (reduction of factor 4 compared to factor 1.7—1.8 for RCONR() (192), related to the extractant s lower stability. 

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