Affinity coefficient

In this situation, it is the ratio of S to I and the relative affinity coefficients (Km and K ) that determines the extent of inhibition. 

If two adsorbates fill the same adsorption volume as shown by the vertical dotted line in Fig. 9.2, their adsorption potentials E and Eq will differ only because of differences in their molecular properties. Consequently, the ratio of adsorption potentials is assumed by Dubinin to be constant and he calls E/Eq the affinity coefficient which, for an adsorbate pair, is a measure of their relative affinities for a surface or their... 

By definition, benzene is standardized as the reference compound for carbonaceous materials, and thus the value of its affinity coefficient //is 1. The relevant parameters of the D-R isotherm can be found in paragraph 1.4, Appendix I. 

Pavlov et al. (1979) directly gives the values of the affinity coefficient (I based on the molar volumes for selected compounds (Table 1.22). 

Here C = total concentration of sorbed penetrant Cf) = saturation capacity of Langmuir isotherm (in "holes") b = affinity coefficient of Langmuir isotherm p = pressure S = solubility. 

Aesthetic properties, 52,875 Affinity coefficient, 682 Aging time, 440 Alternating copolymers, 15,16 Amorphous phase, 32 Andrade s equation, 603, 608 Angle, Brewster, 298 contact, 232 phase, 39... 

Where W is the equilibrium adsorption capacity. Wo is the total volume of the micropores aecessible to the given adsorbate, k is a characteristic constant related to the pore structure of the adsorbent, P is an affinity coefficient, Csai is the saturation concentration in the gas phase of liquid adsorbate at the adsorption temperature T, and C is the eoncentration of adsorbate vapor in equilibrium. Plotting ln(W) versus [RTln(Csai/C)] the parameters K/p and Wo in the DR equation were determined by the slope and the intercept of the linear lines respeetively. The obtained results and correlation coefficients are eompiled in Table 2. This Table shows the DR equation parameters and the... 

The Dubinin-Radushkevitch equation (TOZM theory) was applied to calculate the micropores volume. Affinity coefficient for nitrogen was taken as 0.33, and adsorption phase densi at adsorption temp atures was taken as 0.808 g/cm [11], Micropores size was estimated from adsorption energy defined from the Dubinin-Radushkevitch equation using correlation X=10/E (run), where X is a semi-width of a slit micro-pore [12],... 

In this equation, a and Vm are the thermal coefiBcient of expansion and the molar volume of the hqvud, respectively, P is the affinity coefficient and —hi is the areal enthalpy of wetting (Jm 2) of the external surface area. 

Based on the theory of dispersion interaction, the ratio of the forces of attraction of different molecules is equal to that of polarizability of the molecules of the vapours. This ratio is called an affinity coefficient P and is introduced into the potential function [13]. Furthermore, a parameter k, reflecting the function of the size distribution of volume of the pores, is also included in... 

Here W is the amount of adsorption at P/Po, Wo the micropore volume, Eq the characteristic energy, and the affinity coefficient., 3Eo can be associated with the isosteric heat of adsorption, qst,. =i/e, at the fractional filling of 1/e using the heat of vapourization, AH , at the boiling point ... 

Since N2 adsorption is done at 77 K and CO2 at 273 or 298 K, the experiments cannot be directly compared, which introduces strong concerns about the similarities and differences among both adsorptives. Thus, a better way to compare the two experiments is to plot the characteristic curves [33—35, 37], These characteristic curves, obtained applying the Dubinin-Radushkevich (DR) equation [47] to the adsorption isotherms, are the plot of the logarithm of the volume of liquid adsorbed versus the square of the adsorption potential corrected for the affinity coefficient ((3) of the adsorptive ((/l//3) = (RTln(/o//)/[3), T being the temperature, / the fugacity, and/ the saturation fugacity). 

The adsorption capacity, , and maximum loading, for this isotherm are expressed as the volume adsorbed per unit mass or volume of adsorbent. The function = /( ) is called a characteristic curve and can fit data for one component over a range of temperature—and sometimes for a family of components. The adsorption potential, 8, is defined in Table 14.1. p is called an affinity coefficient that can force data for diverse components to fit a common characteristic curve. 

For this type of isotherm, represents the maximum loading, which correlates with pore volnme among different adsorbents. The other isotherm parameters, and Po [no relation to the terms in Eqnations (14.4) or (14.5)], represent the characteristic parameter of the adsorbent and an affinity coefficient of the compound of interest, respectively. The characteristic parameter, A, defines the shape of the n versns e cnrve. The affinity coefficient, po, adapts the compound of interest to the characteristic cnrve. It is a fndge factoT that has been correlated to the ratio of molar volumes, parachors, or polarizabilities (via the Lorentz-Lorenz equation) of the componnd of interest to that of a reference component (e.g., benzene or n-heptane). These three methods are ronghly eqnivalent in accuracy. The molar volume version is = The only controversy is whether to nse the... 

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