ADSORPTION FROM SOLUTIONS——ADSORPTION FROM MIXED SOLUTIONS OF TRITON X-100 AND SODIUM n-ALKYL SULFATES ON SILICA GEL

The adsorption of Triton X-100 and pure sodium n-alkyl sulfates (C, Cand C) from single and mixed aqueous solutions on silica gel at 25°C has been determined. The adsorption of Triton X-100 shows unusual S-type isotherm. At higher concentrations, the adsorption isotherm reaches a plateau. This plateau coverage corresponds approximately to 1.00 nmper adsorbed molecule. It seems that the packing of adsorbed Triton X-100 on silica/water interface is much less dense than that on the air/water interface. No significant effects of pH and of the presence of sodium chloride （0.1 M） have been observed. Moreover, no significant adsorption for sodium n-alkyl sulfates has been observed, either from single or from the mixed solutions. Thus the competitive adsorption between Triton X-100 and sodium n-alkyl sulfates may not be important.When dealing with the adsorption of Triton X-100 from the mixed solutions, there are two different effects and two different concentration regions can be discerned; (