Binding-site models

Hsi C, Langmuir D (1985) Adsorphon of uranyl onto ferric oxyhydroxides applications of the surface complexation site-binding model. Geochim Cosmochim Acta 49 1931-1941 Ingri J, Widerlund A, Land M, Gustafsson O, Anderson P, Ohlander B (2000) Temporal variation in the fractionation of the rare earth elements in a boreal river the role of colloidal particles. Chem Geol 166 23-45... 

Fig. 14 Plots of observed pseudo-first-order rate constants for the methanolysis of increasing and equimolar [La3 + ] = [32, HPNPP] at 25 °C and pH 5.0 (iV,jV-dimethylaniline buffer, , right axis) or pH 6.7 (2,6-lutidine buffer, , left axis). Lines through the data computed from fits to a standard one-site binding model. Reproduced from ref. 81 with permission.

At first glance the process described in Equation (6) is bimolecular in [La3 + 33], but the kinetics strictly adhere to a first-order process for the loss of starting material. However, the subsequent observation that the products of the reaction actually catalyze the decomposition of starting material allow us to treat the kinetics at each pH according to a simple one-site binding model kobs = /S x [La3 + 33] init (Kd + [La3 + 33]... 

Yates, D. E., S. Levine, and T. W. Healy (1974), "Site-binding Model of the Electrical Double Layer at the Oxide/Water Interface", J. Chem. Soc. Faraday Trans. 70,1807. 

Figure 2. Representation of the possible site forms in the site-binding model which includes the effect of counter-ion adsorption, combined with a diagram of charges and potentials at the insulator/electrolyte interface. Reproduced with permission from Ref. (14). Copyright 1983, North Holland.

Bruyere.V.I.E. Blesa, M.A. (1985) Acidic and reductive dissolution of magnetite in aqueous sulphuric add. Site-binding model and experimental results. J. Electroanal. Chem. 182 141-156... 

Hotta,Y Ozeki, S. Suzuki,T. Imal, S. Ka-neko, S. (1991) Surface characterization of titanated a-Fe203. Langmuir 7 2649—2654 Howe, A.T. Gallagher, K.J. (1975) Mossbauer studies in the colloidal system P-FeOOH — P-Fe20j Structures and dehydration mechanism. J. Chem. Soc. Faraday Trans. I. 71 22-34 Hsi, C.D. Langmuir, D. (1985) Adsorption of uranyl onto ferric oxyhydroxides Application of the surface complexation site-binding model. Geochim. Cosmochim. Acta 49 1931-1941... 

A. (1996 a) Comparison of different site binding models for cation sorption Description of pH dependency, salt dependency and cation proton exchange. J. Colloid Interface Sd. 181 45-59... 

Hsi, C.-K. D. Langmuir, D. 1985. Adsorption of uranyl onto ferric oxyhydroxides application of the surface complexation site-binding model. Geochimica et Cosmochimica A eta, 49,1931 -1941. 

For simple processes in which multiple metals bind to a single ligand = 1 and iEL = 1 (AEE1 = 0) and hence the extended site binding model reduces back the basic site binding model. Figure 10.17 shows... 

Table 10.2 Equilibria, binding constants, extended site binding model parameters and cooperativity for the formation of the Eu(III) complex of 10.9 (L).

The thermodynamics of self-assembled systems are often characterized by positive co-operativity at the molecular level, however the thermodynamic analysis of co-operativity in self-assembly is complexes such as helicates is complicated by the occurrence of both inter- and intramolecular steps. It may be understood using the extended site binding model. 

IV. The Site Binding Models of the Electric Double Layer 148... 

Simultaneously, with the application of the latest experimental techniques, some new theoretical models of edl were constructed. They describe the electric charge and potential distribution in the interfacial region and fit to the experimental data. The new models replace the old classic ones that could not predict some observed parameters from measured ones. Some models, characteristic for metal oxide-electrolyte solution were constructed a porous layer model, then a site binding model and its successive version. 

The site binding model based on reactions (1), (2), (14) and (15), often called surface complexation model (SCM), was, beside the simple site binding models (for example two layer model or constant capacitance model) readily applied to a description of the edl on the metal oxide-electrolyte solution interface. Reactions (14) and (15) describe the adsorption of so-called back-... 

IV. THE SITE BINDING MODELS OF THE ELECTRIC DOUBLE LAYER... 

A separate problem, having an influence on the properties of the surface is the purity of the experimental sample. It means not only the presence of anionic or cationic impurities, but also the presence of the one crystalline form in another one. For example, the even small amounts of the anatase on the surface of the rutile may essentially change the properties of the latter. At the beginning, the edl was characterized by two values pHpzc and pHiep. The critical review of these data was made by Parfitt [164]. A comprehensive survey of pHpzc values, up to nineteenth was done by Lyklema [22]. After the site binding model was worked up, the edl is characterized by the surface hydroxyl group reaction constants. The values of these constants for TiC>2 in different solutions are presented in the papers by James and Parks and Schindler [11,16]. 

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