Adsorption energy parameter

We now study the consequences of these BEP choices to the dependence of predicted rate of methane production on Eads- Making the additional simplifying assumption that the adsorption energy parameters in Eqs. (1.9b) and (1.9c) are the same, one finds for the rate of methane production an expression... 

NEP and PVP. In the polymer where monomers are linked in a chain, hydrophobic parts are largely screened from interactions with the solvent. For free monomers such screening is not possible so that they experience more unfavourable interactions with the solvent. The adsorption energy parameter xs is not affected by the different chemical surrounding of free monomer and polymer segments, since the mechanism for interaction with the surface is hydrogen bonding in both cases (8).)... 

Determination of the segmental adsorption energy. The determina-tion of x ° is also possible. Since x d can be found from Equation 5 if Xsc an the solvency terms are known, we can add xf° and find x ° by Equation 1. The determination of xf° calls for a separate experiment, e.g., an adsorption isotherm of the displacer from solvent, in the absence of polymer. Following such a scheme we used the values of cr obtained from the displacement isotherms of Figure 3 and 4 to determine segmental adsorption energy parameters Xg° for PVP on silica. The required additional information on xdo was obtained from the initial slopes of dis-... 

Fig. 20 Average chemical composition as a function of the adsorption energy parameter for the case when the solution concentrations of A and B monomers are equal. Adapted from [94]...

This is an illustration of the pair exchange principle discussed in secs. 2.1 and 2.4b. Following Silberberg ) and Roe ), we introduce a dimensionless adsorption energy parameter adsorption of 2 from 1. It is defined as... 

Curve 2 describes the case where the charges on the polyelectrolyte and the surface have the same sign and where x > Not only is x now affected by the sedt concentration, but also the effective adsorption energy parameter x which includes the electrostatic Interaction between segments and surface. The chemical adsorption energy of a segment is (see (5.4.11). the electrostatic... 

Figure 3.33. Segment density profiles for the terminally anchored surfactant molecules corresponding to the system of fig. 3.32a. Adsorption energy parameter = 4.8...

The Influence of Surface Corrugation. Figure 5 shows the dependence of the oxygen density profiles in contact with a model III surface on the extent of surface corrugation. The top part shows the results for adsorption energy parameter Do = 12 kJ mol and in the lower part the results for Dq = 30 kJ mol are given. The corrugation parameter a is chosen as 0 (solid line),... 

Numerous attempts to compare the results of theoretical calculations of the thickness of adsorption layer with experimental data were not satisfactory. The reason for the discrepancies is that assumptions made by theoretical calculations are not valid for real systems. For example, most of the calculations were done for an isolated chain, whereas in real systems we always deal with a great number of adsorbed chains. As a result, the chain conformations do not correspond to what is expected by theory. From the experimental point of view, the adsorption layer may be characterized by three parameters available for experimental determination. These are the adsorption energy (parameter%s), the fraction of bound segments, p, and the thickness of adsorption layer. 

In addition to the interacting parameters governing the adsorption of uncharged polymers (adsorption energy parameter and the solvency parameter), the Coulombic interaction is an important aspect of polyelectrolyte adsorption. The ionic forces depend on three main... 

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