Doping salts

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).

From this relationship we may expect to be proportional to the salt thermodynamic characteristics, if u+ and K -,ss have constant values at constant temperature and pressure in a given glassy system. The square root dependency of ionic conductivity on Umy has been experimentally verified over several orders of magnitude. The dissociating species is either a network modifier or a doping salt. Potentiometric (Ravaine and Souquet, 1977) or calorimetric (Reggiani, Malugani and Bernard, 1978)... 

Leiga [66] supplemented kinetic studies with microscopic examination of partially and fully decomposed salt and also investigated the influence of additives. The conclusions of the earlier studies above were confirmed by the demonstration that surface nucleation yielded compact particles which grew in three dimensions during decomposition or photolysis in vacuum. Comparable behaviour was observed for reaction in air of suitably doped salt. When no suitable additive was present, compact nuclei were not seen, which indicates that air inhibits the development of nuclei. 

Fig. 8. Characteristics of J-V (a) and L-V (b) for the single-layered ionic p-i-n PHOLEDs with various concentrations of doped salt of BU4NBF4. (Park et al., 2008)...

These results are unexpected, since it was previously found that molybdate salts were released when submitted to a usual electrochemical reduction and, moreover, their inhibitor properties towards iron were confirmed. XPS analysis of the defect after delamination showed that, in contrast to PPy-PMo, no molybdate could be detected with the PPy-Mo film, confirming that under these conditions no molybdate is released with this doping salt and thus self-heafing was absent. 

Roussel N, Lallemant L, Durand B, Guillemet S, Ching JYC, Fantozzi G et al (2011) Effects of the nature of the doping salt and of the thermal pre-treatment and sintering temperature on spark plasma sintering of transparent alumina. Ceram Int 37 3565-3573... 

Fig. 3. (a) Polyorthotoluidene (emeraldine base form) (b) sulfonated polyaniline (self-doped salt form). 

Stacking face-to-face, slipped (see Fig. 1) and face-to-face (see Fig. 2) configurations of the phthalocyanine dimer were revealed as the most important orientations in the crystal structures of P-phthalocyanine [11] and halogen-doped salts [12]. The association energies and distances of these minima are reported in Table 1. 

In addition, these various oxidation states are pFi sensitive and (except leucoemeraldine) can also be readily switched between doped salt and... 

The interactions of PABA with RNA were investigated with UV-Vis and PM-IRRAS spectroscopy. Figure 3.33 shows the absorption spectra of a PABA layer (both salt and base form) and a PABA/RNA bilayer. The layer of PABA in the salt form (Figure 3.33, a) exhibits the characteristic absorption bands around 400 and 800 nm attributed to tt-tt and bipolaron band transitions, respectively [53, 54]. The blue shift in the bipolaron band of the base form of the PABA layer (Figure 3.33, b) from 800 to 740 nm was observed upon exposure to PBS at pH 7.4 because of the removal of D-fructose and fluoride [37]. Subsequent complexation of the PABA layer in its base form with RNA resulted in a red shift in the bipolaron band from 740 to 800 nm, together with a small increase in the absorbance. These results reportedly confirmed the complexation of RNA with PABA under neutral conditions by the formation of the bilayer through anionic boronate esters, and subsequent conversion of the base form of PABA back to a self-doped salt form. The creation of the anionic tetrahedral boron forms the basis of multilayer formation. Further, the formation of boronate esters and a boron-nitrogen dative bond, as well as electrostatic interactions of anionic phosphates with cationic amines is supported by PM-IRRAS spectroscopy. After complexation... 

Some materials, such as properly doped salt crystals, store the energy deposited by radiation until they are stimulated (e.g., by warming) to release the energy by emitting Ught. These TLDs (thermoluminescent dosimeters) have largely replaced film for monitoring... 

Note that elemental analysis alone is not sufficiently accurate to determine the oxidation state of the as-synthesized polyaniline powder because different oxidation states of PANI differ one from another by only a relatively small amount of hydrogen atoms (see Fig. 1). Nevertheless, elemental analysis can be used to determine whether the as-synthesized poly aniline powder is in the undoped base form or in the doped salt form. The following data are for a typical example. 

The exact location of the dopant ions in the doped sol is not clear. This requires further fundamental study on the solution-sol mixing method. However, it can be assumed that the doped salt is coated on the grain surface of the primary particles in the drying process. After calcination at 450°C, the coated salt is converted to corresponding oxide which may still remain on the grain surface of the primary particles. 

Representative elemental analyses for chlorine (56) are given below. Deprotonation of the initial 100% doped salt with O.IM aqueous NH4OH ... 

In Chapter 5 the study of melts and crystallizations were considered in detail. In the Phosphate Fibers Project the controllable variables of crystallization were limited. After the project was underway two candidates were chosen. All other fibers were given very low priorities. Once the growing medium for [Ca(P03)2]n crystals was specified, only doping salts were studied as composition changes and these were minor constituents. 

HDTTTF molecules in the film were fiilly oxidised to HDTTTF (l3 ) at the initial stage. This iodine doped salt decomposed over a few hours to give a more stable mixed-valence salt resulting in high conductivity. By doping with CI2 and Br2, the film remained in the insulating phase. 

Fig. 1. (a) Leucoemeraldine base (b) emeraldine base (c) pernigraniline base (d) polyCparaphenylene sulfide) le) emeraldine hydrochloride salt polymer (f) poly(orthotoluidine) (emeraldine base form) (g) sulfonated polyaniline (self-doped salt form). 

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