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Self-organizing crystallization induced by evaporation
Salt crystallization by evaporation is widely used in industrial processes, but is also a natural phenomenon occurring frequently around us whenever salt solutions are present and the water evaporates. This can lead to very spectacular natural landscapes but is also a major cause of the weathering of artworks, buildings, soil sodification and corrosion of outdoor electronics. I will discuss the dynamics of crystal growth during evaporation from bulk solution and when salt creeping occurs and show the mechanism behind this self-amplifying process that leads to the formation of 'salt trees'. I will also show how by changing the wettability and/or the porosity of the surface in contact with the salt solution, self-organized crystallization with a fractal morphology spontaneously develops upon drying. I will discuss the importance of the ion advection and diffusion on the crystallization patterns that develop and relate our results to salt crystallization damage observed in our cultural heritage and for works of art.