Triple layer

For example, XRF was used successfully ro analyze two triple-layer films of Cr, Cu, and FeNi deposired on Si substrates. The two films, Tl and T2, have... 

Fig. 13.9 Triple-layer nickel deposit consisting of semi-bright and bright nickel layers with a thin, highly activated layer of nickel between them (after Reference 23)...

Fig 20.13 (a) Electrical double layer and (b) electrical triple layer (after Bockris and Reddy ). Note that Layer 2 in (b) is produced by adsorption of negative ions on the negatively charged... 

The structure of LiTa02F2, as reported by Vlasse et al. [218], is similar to a ReC>3 type structure and consists of triple layers of octahedrons linked together through their vertexes. The layers are perpendicular to the c axis, and each layer is shifted, relative to the layer below, by half a cell in the direction (110). Lithium atoms are situated in the centers of the tetragonal pyramids (coordination number = 5). The other lithium atoms are statistically distributed along with tantalum atoms (coordination number = 6) at a ratio of 1 3. The sequence of the metal atoms in alternating layers is (Ta-Li) - Ta - (Ta-Li). Positions of oxygen and fluorine atoms were not determined. The main interatomic distances are (in A) Ta-(0, F) - 1.845-2.114 Li-(0, F) - 2.087-2.048 (O, F)-(0,F) - 2.717-2.844. 

An electric current can be made to flow in the device twice by using (Fig. 23) a triple-layer design consisting of a conducting polymer, a two-sided tape, and a conducting polymer. When one of the polymer acts as anode, the second acts as a cathode. 

The substitution of the two-sided tape with a film of an ionic conductor gives (Fig. 24) a triple-layered muscle working in air.114 The tape now acts as a solid electrolyte. Nevertheless, the system only works if the relative humidity in air surpasses 60%. Under these conditions, movements and rates similar to those shown by a triple layer working in aqueous solution were obtained. This device was developed in cooperation with Dr. M. A. De Paoli from the Campinnas University (Campinnas, Brazil). At the moment several groups are developing actuators, muscles, and electrochemomechanical devices based on bilayer or multilayer structures.115-125... 

Triple-layer model Of limited value because of the complexity of adsorption sites, unpredictable... 

Wu CH, Shang LL, Cheng FL, Chao YK (2001) Modeling competitive adsorption of molybdate, sulfate and selenate on y-Al203 by the triple-layer model. J Colloid Interf Sci 233 259-264... 

To be useful in modeling electrolyte sorption, a theory needs to describe hydrolysis and the mineral surface, account for electrical charge there, and provide for mass balance on the sorbing sites. In addition, an internally consistent and sufficiently broad database of sorption reactions should accompany the theory. Of the approaches available, a class known as surface complexation models (e.g., Adamson, 1976 Stumm, 1992) reflect such an ideal most closely. This class includes the double layer model (also known as the diffuse layer model) and the triple layer model (e.g., Westall and Hohl, 1980 Sverjensky, 1993). 

In addition to bilayered electrodes with a functional layer and a support layer, electrodes have also been produced with multilayered or graded structures in which the composition, microstructure, or both are varied either continuously or in a series of steps across the electrode thickness to improve the cell performance compared to that of a single- or bilayered electrode. For example, triple-layer electrodes commonly utilize a functional layer with high surface area and small particle size, a second functional layer (e.g., reference [26]) or diffusion layer with high porosity and coarse structure, and a current collector layer with coarse porosity and only the electronically conductive phase (e.g., reference [27]) to improve the contact with the interconnect. 

By introducing methoxy groups, Huang et al. designed the more soluble DSA derivative CBS (193, 194) (Scheme 3.60) [235] and this compound is easy to purify. In the triple layer devices ITO/TPD/CBS/Alq3 or Tb complex/Al, the multipeak emission with band peaks centered at 505 nm was observed when Alq3 was used as the ETM due to emission from the A1Q itself in the ETL. However, a blue emission was observed when the ETM was changed to a Tb complex. 

Triple-layer ODRs, 74 858-859 Triple point of water, 24 439-440 Triple-point temperature, 24 440 Triple porphyrin receptor, 76 787 Triple superphosphate, 77 119-120 Triplet multiplicity, 79 109 Triplet quenching additives, 74 703 Tripodal coelenterands, 24 45... 

The Triple Layer Model. This model developped by Yates et al. (1974) and Davis et al. (1978) uses a similar idea as the Stern model the specifically adsorbed ions are... 

Gouy-Chapman, Stern, and triple layer). Methods which have been used for determining thermodynamic constants from experimental data for surface hydrolysis reactions are examined critically. One method of linear extrapolation of the logarithm of the activity quotient to zero surface charge is shown to bias the values which are obtained for the intrinsic acidity constants of the diprotic surface groups. The advantages of a simple model based on monoprotic surface groups and a Stern model of the electric double layer are discussed. The model is physically plausible, and mathematically consistent with adsorption and surface potential data. 

The structure of the interface according to the Stern model and several limiting-case approximations is presented in Figure 4. The electrostatic models of the interface will be introduced in terms of the most complete one, the triple layer model (Figure 4a). Then the relationship of the triple layer model to the simplified models in Figures 4b-d will be discussed. 

Stern used this simplification in his calculations. The simplified model with only one Helmholtz capacitance is commonly referred to as the Stern model (Figure 4b), while the "extended" Stern model (Figure 4a) is designated the triple layer model. 

Diprotic Surface Groups. Most of the recent research on surface hydrolysis reactions has been interpreted in terms of the diprotic surface hydrolysis model with either the triple layer model or the constant capacitance model of the electric double layer. The example presented here is cast in terms of the constant capacitance model, but the conclusions which are drawn apply for the triple layer model as well. 

An extension of this method has been developed for the triple layer model which allows data obtained at several values of ionic strength to be considered simultaneously (7, 13.). However, this "double extrapolation technique" involves the same sort of approximation. 

The discussion above pertains to the diprotic acid chemical model and the constant capacitance electrostatic model. It is interesting to note that in some applications of the triple layer model with site binding of electrolyte ions at the IHP, the... 

The constants and parameters required for making triple layer model (TLM) computations (e.g.,, K, Clt C2, and... 

Table I. Triple Layer Model Parameters and Values...

---