Articles and methods providing liquid-impregnated scale-phobic surfaces

Abstract

This invention relates generally to articles, devices, and methods for inhibiting or preventing the formation of scale during various industrial processes. In certain embodiments, a vessel is provided for use in an industrial process, the vessel having a textured, liquid-impregnated surface in contact with a mineral solution, wherein the liquid-impregnated surface comprises a matrix of features spaced sufficiently close to stably contain an impregnating liquid lubricant therebetween or therewithin, wherein the impregnating lubricant has a low surface energy density, and wherein the spreading coefficient Sos(w) of the impregnating lubricant (subscript ‘o’) on the substrate (subscript ‘s’) in the presence of the salt solution (subscript ‘w’) is greater than zero, such that the impregnating lubricant fully submerges the textured substrate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 61 / 922,574, filed Dec. 31, 2013, entitled “Articles and Methods Providing Liquid-Impregnated Scale-Phobic Surfaces,” and U.S. Provisional Patent Application Ser. No. 61 / 771,486, filed Mar. 1, 2013, entitled “Articles and Methods Providing Liquid-Impregnated Scale-Phobic Surfaces,” the disclosures of which are incorporated herein by reference in their entireties.FIELD OF THE INVENTION[0002]This invention relates generally to articles, devices, and methods for inhibiting or preventing the formation of scale on surfaces, and more particularly, to articles, devices, and methods for inhibiting or preventing the formation of mineral scale on surfaces in industrial processes.BACKGROUND OF THE INVENTION[0003]Scale formation is a persistent problem encountered in a variety of industries, such as the oil and gas industry, desalination plants, and pow...

AI Technical Summary

Benefits of technology

[0008]Presented herein are liquid-impregnated surfaces that combine the desired properties of low surface energy and low roughness along with a liquid-liquid interface, all of which mitigates scale nucleation and / or growth on the surface. Furthermore, it is shown that standard vessel materials, such as steel (e.g., in some embodiments, the steel is carbon steel or stainless steel), aluminum, copper, or tin, for example, can be inexpensively treated to produce a microtextured surface which is suitable for liquid impregnation. Moreover, an existing industrial vessel can be retrofitted by microtexturing its interior surface, then impregnating the microtextured surface with a low surface-energy impregnating liquid.

[0009]Vessels (e.g., tanks or pipes) are presented herein that inhibit the formation of mineral scale deposits thereupon. The vessel has a liquid-impregnated interior surface, wherein the impregnating liquid is stably held within a matrix of micro- or nano-scale (solid) features on the surface, or the impregnating liquid fills pores or other tiny wells (e.g., wells, cavities, hollows, recesses, pits, etc.) on the surface. The impregnating liquid is stably contained and does not leach significantly (or at all) into the contents of the vessel, even when the vessel contains another liquid, such as water. The impregnated lubricant is stabilized by capillary forces arising from the micro- or nano-scopic texture and can impart remarkable mobility to motive phase(s) (e.g., liquid droplets) on the surface.

Problems solved by technology

Scale formation is a persistent problem encountered in a variety of industries, such as the oil and gas industry, desalination plants, and power plants, among others, and results in a significant loss of efficiency and useful lifetime of process equipment in these industries.

For example, scale formation or precipitation fouling of heat exchanger surfaces and oil and gas pipelines are a significant problem.

The challenges associated with scale formation have a major effect on the capital and operating costs of most conversion processes.

Besides having low solubility limits, a major difficulty with CaSO4 is the phase transformation between its hydrates and polymorphs, particularly at elevated temperatures (above 100° C.

Furthermore, the solubility of CaSO4 is strongly affected by the presence and concentrations of other ions in the system.

Another challenge with CaSO4 scale deposits is that they form even at low pH and can be removed effectively only by mechanical means, which significantly increases the operating cost of the plant.

However, these techniques are suboptimal because of the high, often prohibitive, costs involved in the removal process, as well as their environmentally unfriendly nature.

However, such chemical additives and coatings involve polymers, thiols, or silanes, which can deteriorate under harsh environments that are generally encountered during scale formation in various industries, creating an environmental hazard.

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