ADSORPTION AT THE RUTILE-SOLUTION INTERFACE: I. THERMODYNAMIC AND EXPERIMENTAL STUDY.
Abstract
A detailed thermodynamic analysis of the double layer at the interface, simple inorganic oxide-aqueous solution, is presented with special emphasis on the assumptions normally made in relating experimental observation to theoretical treatment. An experimental study of the adsorption of potential-determining ions (H(+), OH(-)) at the rutile (TiO2)/solution interface is reported. The point of zero charge (pzc) for TiO2 at room temperature was observed to lie at pH 6.0, independently of its crystalline modification, but was lowered to below pH 4 by heat treatment of the oxide prior to adsorption measurement. The pzc was also observed to approach the neutral point (1/2 pKw) with increasing temperature in the temperature range, 25C to 95C. A thermodynamic consideration of the transfer of cationic and anionic potential-determining species from the aqueous solution to the surface at the pzc allowed the difference in the standard entropy of transfer to be estimated from this information. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1968
- Accession Number
- AD0664507
Entities
People
- P. L. De Bruyn
- Y. G. Berube
Organizations
- Massachusetts Institute of Technology