Some Reflections on Acid-Base Solid Surface Free Energy Theories

This paper considers the correctness of the application of Good-van Oss theory (vOGT) to the calculation of acid-base components of solid surface free energies. Theory equations are written in a matrix form, and their application is analyzed particularly from a mathematical point of view. A calculation procedure similar to the approach used for other scales of acid-base strength is suggested to obtain in a straightforward manner the necessary material coefficients. The chemical consequences of these considerations are also discussed. The acceptability of current experimental literature data and the validity of the calculations obtained from them by the proposed method are considered, showing the origin of some inconsistencies in current results. Some general considerations regarding the difficulties commonly encountered in the application of vOGT are also discussed, and it is shown that they can be rationalized or eliminated with more acid solvents being included in the solvent set and the properties of the reference solvent being correctly chosen. The difficulties encountered in correctly expressing the acid properties of some polymers are closely examined. Finally, some indications are given of the future possible developments of vOGT. Copyright 1997 Academic Press. Copyright 1997Academic Press