Hollow porous materials with architected fluid interfaces for reduced overall pressure loss

Patent metadata

Field	Value
Publication number	US-9862151-B1
Application number	US-201615230241-A
Country	US
Kind code	B1
Filing date	Aug 5, 2016
Priority date	Sep 14, 2012
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A structure including a hollow porous material with an architected fluid interface to the hollow porous material and methods of forming the same. The architected fluid interface may be in the form of a manifold with tapered openings, each providing a gradually narrowing transition to the hollow channels within which fluid may flow through the hollow porous material. The material may be formed by forming an open-celled sacrificial scaffold, immersing one surface of the open-celled sacrificial scaffold in a bonding agent, attaching a face sheet to the surface to form a sacrificial scaffold assembly, coating the assembly with a coating material, and removing the sacrificial scaffold assembly.

First claim

What is claimed is:

1. A method for forming a three-dimensional hollow open-celled structure with attached manifold, the method comprising:
forming an open-celled sacrificial scaffold;
forming a sacrificial manifold core on a first surface of the open-celled sacrificial scaffold;
forming a coating on the open-celled sacrificial scaffold and on the sacrificial manifold core; and
removing the open-celled sacrificial scaffold and the sacrificial manifold core to form the three-dimensional hollow open-celled structure with an attached manifold.

2. The method of claim 1 , wherein the forming of the sacrificial manifold core on the first surface of the open-celled sacrificial scaffold comprises:
immersing the first surface of the open-celled sacrificial scaffold in a liquid matrix to a first depth;
applying a face sheet to the first surface of the open-celled sacrificial scaffold; and
solidifying the liquid matrix.

3. The method of claim 2 , wherein the liquid matrix comprises thiol-ene as a major component.

4. The method of claim 2 , wherein the face sheet comprises, as a major component, a substance selected from the group consisting of polylactic acids, thiol-enes, and combinations thereof.

5. The method of claim 2 , wherein the first surface is substantially planar.

6. The method of claim 5 , wherein the first depth is one-half a unit cell dimension in the direction perpendicular to the first surface.

7. The method of claim 1 , wherein the open-celled sacrificial scaffold comprises thiol-ene as a major component.

8. The method of claim 1 , wherein the coating comprises, as a major component, a substance selected from the group consisting of polymers, metals, ceramics, composite materials, hydrophilic materials, hydrophobic materials, photocatalytic materials, and combinations thereof.

9. The method of claim 8 , wherein the coating comprises, as a major component, a polymer selected from the group consisting of fluoropolymers, thiol-enes, parylene AF4, parylene-N, parylene-C, and combinations thereof.

10. The method of claim 1 , wherein the removing of the open-celled sacrificial scaffold and the sacrificial manifold core comprises etching out the open-celled sacrificial scaffold and the sacrificial manifold core using an etchant.

11. The method of claim 10 , wherein the etchant comprises, as a major component, a base solution.

12. The method of claim 11 , wherein the etchant comprises, as a major component, a substance selected from the group consisting of sodium hydroxides, potassium hydroxides, low molecular weight alcohols, water, lithium bromides, organic amine bases, and combinations thereof.

13. The method of claim 10 , wherein the removing of the open-celled sacrificial scaffold and the sacrificial manifold core further comprises exchanging for the etchant a liquid selected from the group consisting of low molecular weight alcohols, liquid carbon dioxides, and combinations thereof.

14. The method of claim 13 , wherein the density of the liquid differs from the density of the etchant by at least 1%.

15. The method of claim 10 , wherein the removing of the open-celled sacrificial scaffold and the sacrificial manifold core further comprises removing a liquid by freeze drying or supercritical drying.

16. The method of claim 1 , wherein the removing of the open-celled sacrificial scaffold and the sacrificial manifold core comprises burning out the open-celled sacrificial scaffold and the sacrificial manifold core.

17. The method of claim 1 , further comprising selectively removing portions of the coating before the removing of the open-celled sacrificial scaffold and the sacrificial manifold core.

18. The method of claim 1 , wherein the open-celled sacrificial scaffold is an open-celled sacrificial scaffold, comprising:
a plurality of first truss elements defined by a plurality of first self-propagating polymer waveguides and extending along a first direction;
a plurality of second truss elements defined by a plurality of second self-propagating polymer waveguides and extending along a second direction; and
a plurality of third truss elements defined by a plurality of third self-propagating polymer waveguides and extending along a third direction.

19. The method of claim 1 , wherein the open-celled sacrificial scaffold is an open-cell foam.

20. The method of claim 1 , further comprising providing a particulate filter in the manifold.

Assignees

• Hrl Lab Llc

Inventors

• Maloney Kevin J
• Roper Christopher S

Classifications

• B29C41/02

  for making articles of definite length, i.e. discrete articles · CPC title

• B29K2881/00

  Use of polymers having sulfur, with or without nitrogen, oxygen, or carbon only, in the main chain, as mould material · CPC title

• E04C3/28

  of materials not covered by groups E04C3/04 - E04C3/20 · CPC title

• B29C33/40

  Plastics, e.g. foam or rubber · CPC title

• F28F2260/00

  Heat exchangers or heat exchange elements having special size, e.g. microstructures · CPC title