This Appendix to the Manual of Symbols and Terminology for Physicochemical Quantities and Units (Butterworths: 1970 and Pure and Applied Chemistry, 1970, 21, No. 1) has been prepared by the Commission on Colloid and Surface Chemistry of the Division of Physical Chemistry of the International Union of Pure and Applied Chemistry. It is the outcome of extensive discussions within the Commission and its Sub-commissions, with other IUPAC Commissions, and with persons and organizations outside IUPAC, over the period 1961-19711. A tentative version of these proposals was issued by IUPAC as Information Bulletin No. 3 (January 1970): the text bas been revised in the light of the criticisms, comments and suggestions which were received, and the present version was formally adopted by the IUPAC Council at its meeting in Washington, DC, in July 1971.
The present proposals are based on the general principles set out in detail in Section 1 of the Manual of Symbols and Terminology. Since colloid and surface chemistry are subdivisions of physical chemistry, and there is substantial overlap between these fields and others, in particular with electrochemistry and macromolecules, it is important that terms in colloid and surface chemistry should not be used in a sense different from that common to physical chemistry in general or to its other subdivisions. On the other hand, it is equally important to avoid inconsistencies between the meanings of terms employed in scientific aspects of colloid and surface chemistry, and the same terms used in industrial, engineering and technological contexts. It has also been necessary to balance the desirability of retaining terms because of historical connections or wide common usage against the need to develop a more consistent and logical structure as colloid and surface chemistry evolves into a more quantitative scientific discipline. It has not yet been possible to resolve all the consequent problems. For this reason, this Appendix will be issued in two parts.
Part II will include revised versions of the sections in the Tentative Manual on optical properties and rheology. Furthermore, the section on electrochemical nomenclature in Part 1 appears only in skeleton form, pending the finalization by the Commission on Electrochemistry of their nomenclature proposals. Proposals for nomenclature in the field of heterogeneous catalysis are also in preparation and are planned for inclusion in Part II.
This Appendix consists of three Sections: the first is concerned with definitions and terminology, and with recommendations for appropriate symbols; the second is a list of recommended symbols; and the third an alphabetical index of terms defined, together with the corresponding symbols.
D. H. Everett
Commission on Colloid and Surface Chemistry
6 January 1972