Articles having a surface with low wettability and method of making

Abstract

An article comprises a textured surface disposed on a substrate. The surface has an effective liquid wettability sufficient to generate, with a reference liquid, a contact angle in a range from about 120° to about 180°. The surface comprises a material having a nominal liquid wettability sufficient to generate, with the reference liquid, a nominal contact angle in a range from about 60° to about 90°, the material comprising at least one material selected from the group consisting of a polymer and a ceramic. The properties of the surface may include low-drag or low-friction, self-cleaning capability, and resistance to icing, fouling, and fogging, and the like. Methods of making such a surface are also described.

Description

BACKGROUND OF INVENTION [0001] The invention relates to surfaces having low liquid wettability. More particularly, the invention relates to such surfaces, where the surface is characterized by having one or more of the following properties: low-friction properties, self-cleaning capability, and resistance to icing, fouling, and fogging. Even more particularly, the invention relates to articles having such surfaces. [0002] The “liquid wettability” of a solid surface is determined by observing the nature of the interaction occurring between the surface and a drop of a given liquid disposed on the surface. A surface having a high wettability for the liquid tends to allow the drop to spread over a relatively wide area of the surface, thereby “wetting” the surface. In the extreme case, the liquid spreads into a film over the surface. On the other hand, where the surface has a low wettability for the liquid, the liquid tends to retain a well-formed, ball-shaped drop shape. In the extreme ...

AI Technical Summary

Benefits of technology

[0008] The present invention meets these and other needs by providing an article having a surface with a low liquid wettability. The surface provides properties that may include, as non-limiting examples, one or more of low-drag or low-friction properties, self-cleaning capability, and resistance to icing, fouling, and fogging.

Problems solved by technology

By way of example, so-called “hydrophilic” materials have relatively high wettability in the presence of water, resulting in a high degree of “sheeting” of the water over the solid surface.

“Hydrophobic” materials have relatively low water wettability; so-called “superhydrophobic” materials have even lower water wettability, resulting in surfaces that in some cases may seem to repel any water impinging on the surface due to the insignificant amount of interaction between water drops and the solid surface.

Such coatings are subject to rapid wear and are not thermally or chemically stable at higher temperatures.

Current approaches to the production of articles having minimal interaction with fluids have been focused on applications of limited scope, and have produced only limited success.

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