Mixed anion effect

Fig. 4.2 Typical variations in ionic conductivity with composition. In all cases, variations in alkali or silver content are very low compared to the observed variation in log a (a) influence of the network modifier (LijS) (b) influence of a doping salt (c) mixed alkali effect (d) mixed anion effect. References for data are indicated in Souquet and Perera (1990).

S cm at 300°C, which is higher than that of the respective binaiy systems. The origin of the mixed alkaline effect as well as of the mixed anion effect is still under debate. 

Some reactions of this type are accelerated further by use of naphthoic acid as an additive. This effect is believed to result from formation of a mixed anionic cuprate... 

The dielectric constant and breakdown field of a material are not the only considerations. Because a capacitor is used for charge storage, the leakage properties of the film are also critical. These are largely controlled by the defects in the films which can include oxygen (anion) vacancies or mixed valence effects in the cations. It is important that films that are as fully oxidized as possible be studied. 

Significant non-idealities can occur in the solids with two kinds of mobile cations (or anions). The so-called mixed alkali effect refers to the partly extremely strong depression of the alkali ion conductivity in crystals or glasses if substituted by another alkali ion. This is explained by the individually preferred environments and their interactions.221"228... 

The factors that affect phase separation discussed in this section include anion effect, divalent effect, alkaline effect, mixing effect of interstitial flow, and the synergy of mixed surfactants. 

The acidity trend is consistent with the above analysis. Taking into account that these solvent systems differ only in the nature of the anion and that a values are mainly determined by the nature of the cation, the behaviour can be connected with an anion effect on the acidity. The positive deviation manifested in some solvents with [bmim][BF ] and [bmim][PF ] and the slight synergetic effect can be attributed to the strong intersolvent interactions mentioned above. The almost Unear decrease of the property in several mixtures comprised of [bmim][Cl] and [bmim][Br] also demonstrates that the mixed solvent is less favoured, although a slight negative deviation in some solvents with [bmim][Cl] can be noticed. 

It has been known for almost three decades that mixing anionic and ethoxylated non-ionic surfactants allows to produce microemulsions which are insensitive to temperature changes [60]. The expressions of the HLD for the two kind of surfactants (see Eqs. (3.24) and (3.25)) exhibit a different sign before the aj and cj temperature coefficients. The signs express the fact that the affinity of water for an ionic surfactant increases when the temperature increases, whereas the reverse takes place with a polyethoxylated non-ionic surfactant. Coefficient ax is about 0.01 for alkyl benzene sulphonates and 0.02 for alkyl trimethyl quaternary ammoniums, while cT is in the 0.05-0.1 range for ethoxylated alcohols and phenols, with a tendency to increase with the ethoxylation degree and to decrease with increased temperature. The fact is that the effect of the temperature is several times stronger with non-ionics, hence a mixture insensitive to temperature should contain more ionic than non-ionic, so that the effects could cancel out [60-62]. 

Other CTAs and inhibitors also tried (about 0.05 M) were anionic mer-captoacetate and mercaptosuccinate and cationic isopropylamine, 1-dimeth-ylamino-2-propanol, cysteamine hydrochloride, and copper sulfate. The pH was adjusted as necessary to yield the desired ions. None of the ionic CTAs reduced the measured PLMA MW, although mercaptoacetic acid at a pH of 2.2 (mixed anionic and neutral species) reduced the molecular weight almost to that obtained with mercaptoethanol. The ionic CTAs may increase the micelle aggregation number (electrolyte effect). Cu(II) precipitated surfactant, but the other solutions were clear. 

After 1865, narrow absorption bands played a role for evaluating the separation of two elements, as elaborated by Auer von Welsbach, and Soret (who was professor of physics at the University of Geneva, where Marignac was professor of chemistry and mineralogy) ascribed some absorption bands prominent in some erbium fractions to a new element. A few years after, these bands turned out to occur in holmium, separated by Cleve in 1879. There are minor chemical effects in sulfate complexes, mixed anion-hydroxo complexes, etc., on absorption spectra in solution. 

Liu G, Hou Y, Xiao X, Zhang G (2010) Specific anion effects on the growth of a polyelectrolyte multilayer in single and mixed electrolyte solutions investigated with quartz crystal microbalance. J Phys Chem B 114 9987-9993... 

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