Fluid handling component with ultraphobic surfaces

Abstract

A fluid handling component having a durable ultraphobic fluid contact surface that is capable of exhibiting ultraphobic properties at liquid pressures of one atmosphere and above. The surface generally includes a substrate portion with a multiplicity of projecting regularly shaped microscale or nanoscale asperities disposed so that the surface has a predetermined contact line density measured in meters of contact line per square meter of surface area equal to or greater than a contact line density value “ΛL” determined according to the formula: ΛL=-10,330γ⁢ ⁢cos⁡(θa,0+ω-90⁢°)where γ is the surface tension of the liquid in Newtons per meter, θa,0 is the experimentally measured true advancing contact angle of the liquid on the asperity material in degrees, and ω is the asperity rise angle in degrees.

Description

RELATED APPLICATIONS [0001] This application is a Continuation of application Ser. No. 10 / 454,742 filed Jun. 3, 2003, entitled “Fluid Handling Component with Ultraphobic Surfaces”, which claims the benefit of U.S. Provisional Application Ser. No. 60 / 462,963, entitled “Ultraphobic Surface for High Pressure Liquids”, filed Apr. 15, 2003, hereby fully incorporated herein by reference.FIELD OF THE INVENTION [0002] This invention relates generally to fluid handling components, and more specifically to a fluid handling component having ultraphobic fluid contact surfaces. BACKGROUND OF THE INVENTION [0003] Fluid handling components, such as channels, pipes, tubes and associated fittings and other components have been used for millennia to convey liquids from one place or process to another. Friction of moving fluids with the fluid handling components, however, has always presented a significant challenge to achieving maximum efficiency in fluid handling systems. Friction increases the ener...

AI Technical Summary

Benefits of technology

"The invention is about a fluid handling component that has a durable surface with very small bumps and holes that can handle liquids with high pressure. These surfaces have been tested to have a contact line density of at least 10,000 per square meter. The bumps can be formed on the surface using various methods such as photolithography or nanomachining. The surfaces also have a critical asperity height of at least 10 meters. The components made with these surfaces have very low friction, can handle fluids with high pressure, and are resistant to bio-film growth. This makes them useful for applications such as warm water storage and circulating systems."

Problems solved by technology

Friction of moving fluids with the fluid handling components, however, has always presented a significant challenge to achieving maximum efficiency in fluid handling systems.

Friction increases the energy required to pump a fluid through a system and reduces the fluid flow rate through the system.

Previous attempts at reducing fluid friction in fluid handling systems have been only partially successful.

While fluid friction may be reduced by providing smoother fluid contact surfaces, the amount of reduction achievable is limited.

Likewise, the use of conventional materials with improved surface wetting characteristics, such as PTFE, may result in some improvement in friction properties, but the amount of improvement is limited.

Also, the choice of materials may be restricted based on the compatibility of the fluid with the materials to be used.

Under other circumstances, however, roughness may cause the liquid to adhere less strongly to the rough surface than the smooth surface.

Previous attempts at producing ultraphobic surfaces with micro / nanoscale asperities have been only partially successful.

Moreover, fluid pressure in fluid handling applications where ultraphobic surfaces may be desirably used often exceeds one atmosphere, and in extreme applications, may reach hundreds of atmospheres.

Ultraphobic surfaces produced to date appear to be effective as an ultraphobic surface only up to about 0.1 atmospheres, severely limiting the applicability of such surfaces in fluid handling component applications.

These coatings are easily physically damaged, even by fluid pressure, so as to be ineffective.

These droplets are not easily removed, and in a large system, may include a substantial quantity of fluid.

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