But aren’t all soaps metal soaps? A review of applications, physico-chemical properties of metal soaps and their occurrence in cultural heritage studies

Abstract

Metal soaps, the organic salts resulting from the interaction of fatty acids and metal cations, arouse interest in the scientific field because of their versatility in a great range of chemical applications as well as because of the mechanism of their formation during degradation processes. This article presents a review of the synthetic pathways used to produce metal soaps, their relevant physico-chemical properties, and how these reflect in their applications. Common industrial uses of metal soaps are reported, with a particular focus on those applications, such as cosmetics, paints, and coatings, that have an impact on the cultural heritage field. In addition, the occurrence of metal soaps in cultural heritage studies is presented, ranging from archaeological and ethnographic artefacts to fine art objects, and discussed per class of materials.