ABSTRACT
I. Introduction 273 II. Mechanism of Surface Charging in Nonaqueous Media 274
III. Experimental Methods 278 IV. Ions in Solution 280
A. pH scales 282 V. Empirical Solvent Scales 285
VI. Surface Charge 289 A. Silica 290 B. Rutile 296 C. Anatase 296 D. Alumina 297 E. Hematite 298
VII. C-Potentials 299 A. ^-potentials in mixed solvents rich in water 299 B. ^-potentials in nonaqueous or almost nonaqueous solvents 301
VIII. Stability 307 A. Silica 308 B. Goethite 308 C. Alumina 308 Note Added in Proof 308 Symbols and Abbreviations 308 References 310
I. INTRODUCTION
There are applications of chemistry in which “solution” and “aqueous solution” or “solvent” and “water” are almost pairs of synonyms. Although theoretically water can be replaced by another solvent, the abundance and low cost of water and its excellent physical, chemical, and physiological properties make it hard to imagine that any other solvent could replace water in certain fields; and in view of the growing ecological
awareness, the “environment-friendly” technologies based on water have a much better prospect than those in which nonaqueous solvents are involved, so water is probably also the solvent of the future.
