Scale formation is a widespread problem in industries and households—from scaling of cooking pots in ancient times to the plugging of pipelines in the modern age. Developing surfaces that have a low affinity to scale has been an area of great interest in the last decade. In this work, we demonstrate the anti-scaling properties of textured surfaces impregnated with a lubricant. Since scale deposition can be reduced by lowering the nucleation rate, which depends on the properties of the substrate, we optimize the design of the lubricant-impregnated surfaces (LIS) based on the surface tension of the lubricant and its spreading coefficient on the solid. Scale deposition experiments show that the nucleation rate on optimized LIS is reduced owing to their low surface energy and low density of nucleation sites. Mass gain measurements indicate that the optimized LIS perform 10 times better than uncoated smooth surfaces. This idea is extended to an engineering material like stainless steel and, along with low scale deposition, low adhesion of scale to LIS is also achieved.

Paper: Srinivas Bengaluru Subramanyam, Gisele Azimi, and Kripa K. Varanasi
Advanced Materials Interfaces

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