HDP-illite

Figure 4. Adsorption excess isotherms on HDP-illite derivatives in methanol(l)+ben-zene(2) mixtures. 1-5 increasing HDP+ cation surface concentration.

FIG. 14 Free enthalpy of adsorption on Na-illite and on HDP-illite and on HDP-illite derivatives in methanol (l)-benzene (2) mixtures. Na, sodium illite 1,2,3 hexadecylpyri-dinium illites. 

FIG. 15 Free enthalpy of adsorptioin on Na-illite and HDP-illite derivatives in methanol(l)-benzene(2) mixtures. Na sodium-illite curves 1-3 HDP-illites. 

FIG. 17 Determination of the adsorption capacities from Eq. (15). Curve 1 Na-iUite curves 2-4 HDP-illites curve 5 Na-montmorillonite in the methanol) l)-benzene(2) mixture. 

The excess free energy functions given by integration of the excess isotherms, Eq. (5), reflect the extent of the hydrophobization (Fig. 14). Methanol displaces benzene with a maximum change in free energy on sodium illite. The displacement process results in smaller free energy changes on HDP-treated surfaces— the functions shown for the sample with maxima at the azeotropic compositions. 

Fig. 11 Adsorption isotherms of HDP+ on layer silicates mont-morillonite (o), vermiculite (a), illite (x) and kaolinite (n)...

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