Abstract: Method for promoting nucleate boiling on an interior surface of a vessel for boiling fluid in an industrial process, the method comprising the steps of: providing the vessel having the interior surface; controllably depositing a scale layer having a non-zero thickness onto the interior surface; monitoring an average thickness, x, of the deposit of the layer; and maintaining the average thickness, x, of the layer below a predetermined value or within a predetermined range of values during the operational life of the vessel, wherein x<k/h, wherein k is the effective thermal conductivity of the interior surface of the vessel and h is the heat transfer coefficient at the interior surface of the vessel in contact with the boiling fluid.

Abstract: The present disclosure provides, among other things, scale-coated surfaces, vessels with controlled deposits of scale, and associated methods for enhanced boiling heat transfer. It is presently found that creating and/or maintaining a scale deposit at a controlled thickness actually enhances a type of boiling called nucleate boiling, which improves heat transfer.

Abstract: Hierarchical nanostructures and methods of fabrication. The structures include particles having a metal oxide outer shell with metal oxide wires extending from the outer shell. A multiscale structure according to the invention has particles above and below a critical size wherein the particles above the critical size have wires extending from the surface. These structures may be fabricated from a mixture prepared of relatively smaller metal particles having a size threshold below a threshold for nanowire formation and of relatively larger metal particles having a size above the threshold for nanowire formation. The mixture is oxidized at a selected temperature and for a selected time whereby the relatively smaller particles sinter and nanowires grow on the relatively larger particles thereby creating tunable hierarchical structures with metal-to-metal contact between the particles.