A method has been developed to obtain adsorption isotherms by analyzing spreading pressure-surface charge data obtained throughout a range of potentials. The Gibbs adsorption equation is used to infer solute activities of uracil and of caffeine in aqueous electrolyte solutions. Activities of uracil vary nearly in direct proportion with concentrations; activities for caffeine deviate considerably from linearity with concentration in the 10 to 50 mM range. Activity data are compared with literature results and with activities obtained in this laboratory from partition experiments.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry