Accession Number : AD0664507

Title :   ADSORPTION AT THE RUTILE-SOLUTION INTERFACE: I. THERMODYNAMIC AND EXPERIMENTAL STUDY.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF METALLURGY AND MATERIALS SCIENCE

Personal Author(s) : Berube,Y. G. ; de Bruyn,P. L.

Report Date : JAN 1968

Pagination or Media Count : 44

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)

Descriptors :   (*RUTILE, ADSORPTION), OXIDES, INTERFACES, SOLUTIONS(MIXTURES), ELECTRIC DOUBLE LAYER, THERMODYNAMICS, ELECTROLYTES, VOLUMETRIC ANALYSIS, ENTROPY, THESES

Subject Categories : Physical Chemistry
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE