Membrane-based article and associated method

• US 20070131611A1
• Filed: 05/15/2006
• Published: 06/14/2007
• Est. Priority Date: 12/13/2005
• Status: Abandoned Application

• Current Assignee: Momentive Performance Materials Incorporated (Momentive Performance Materials Holdings LLC)
• Original Assignee: General Electric Company
• Inventors: Wang, Dong, Peng, Wenqing, Rajaraman, Suresh, Xia, Zijun, Leatherman, Mark, Policello, George, Cao, Chun
• Application Number:
  US11/434,102
• Publication Number:
  US 20070131611A1
• Time in Patent Office: Days
• US Class Current: 210/500.270
• CPC Class Codes: B01D 2323/02 Hydrophilization
• CPC Class Codes: B01D 67/0088 Physical treatment with compounds, e.g. swelling, coating or impregnation
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 71/36 Polytetrafluoroethene
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/249954 With chemically effective material or specified gas other than air, N, or carbon dioxide in void-containing component

Abstract

An article includes a membrane having pores extending therethrough, and a surfactant in contact with a surface of the membrane. The surfactant may function as a superspreader when in solution. The membrane surface may wet in response to contact with a fluid. An associated method is provided.

Claims

1. An article, comprising:

a membrane having pores extending from a first surface through the membrane to a second surface; and

a surfactant in contact with at least one surface of the membrane, and the surfactant is capable of functioning as a superspreader when in solution, and the article is capable of wetting the membrane in response to contact with a fluid.

2. The article as defined in claim 1, wherein the surfactant comprises an organosiloxane having formula (I):

(R¹R²R³SiO_1/2)(R⁴R⁵SiO_2/2)_n(R⁶R¹⁰SiO_2/2)_p(R⁷R⁸R⁹SiO_1/2) 

 

(I)

wherein “

n”

is an integer from 0 to 50;

“

p”

is an integer from 1 to 50;

R¹ to R⁹ are independently at each occurrence a hydrogen atom, an aliphatic radical, an aromatic radical, or a cycloaliphatic radical; and

R¹⁰ is a polyoxyalkylene having formula (II);

R¹³(C₂H₃R¹¹O)_w(C₃H₆O)_x(C₄H₈O)_yR¹² 

 

(II)

wherein “

w”

, “

y” and

“

z”

are independently an integer from 0 to 20, with the proviso that “

w”

is greater than or equal to 2 and “

w+x+y”

is in a range of from about 2 to about 20;

R¹¹ is a hydrogen atom or an aliphatic radical, R¹² is a hydrogen atom, an aliphatic radical, or a carboxylate; and

R¹³ is a divalent aliphatic radical having structure (III);

—

CH₂—

CH(R¹⁴)(R¹⁵)_zO—

 

 

(III)

wherein R¹⁴ is a hydrogen atom or an aliphatic radical, R¹⁵ is a divalent aliphatic radical, and “

z”

is 0 or 1.

3. The article as defined in claim 2, wherein the surfactant comprises a trisiloxane alkoxylate.

4. The article as defined in claim 1, wherein the surfactant comprises a first hydrophobic moiety linked to a spacer, and the spacer is linked to a second hydrophobic moiety to form a Gemini surfactant, and each hydrophobic moiety comprises at least one silicon atom.

5. The article as defined in claim 4, wherein the spacer comprises a moiety selected from the group consisting of an ammonium group, a carboxylic acid group, a sulfonic acid group, a sulfuric acid group, a sulfinic acid group, a phosphonic acid group, a boronic acid group, a fatty acid group, a fatty acid ester group, a peptide group, a carbohydrate group, and a polyether.

6. The article as defined in claim 4, wherein the spacer comprises a polyether having formula (VI)

—

CH₂)_a—

O—

(C₂H₄O)_b(C₂H₃R¹⁶O)_c—

(CH₂)_a—

 

 

(VI)

wherein “

a”

is independently at each occurrence an integer from 1 to 6, “

b” and

“

c”

are independently integers from 0 to 12, with the proviso that “

b +c”

is less than or equal to 12, and R¹⁶ is an aliphatic radical.

7. The article as defined in claim 4, wherein one or both of the first hydrophobic moiety or the second hydrophobic moiety comprises an organosiloxane group having a formula (VII) or (VIII):

(R¹⁷R¹⁸R¹⁹SiO_1/2)₂(R²⁰R²¹SiO_2/2)_d(R²²SiO_2/2)—

 

 

(VII)
(R²³R²⁴R²⁵SiO_1/2)(R²⁶R²⁷SiO_2/2)_f(R²⁸R²⁹SiO_1/2)—

 

 

(VIII)

wherein “

d”

is an integer from 0 to 50, “

f”

is an integer from 1 to 50, and R¹⁷ to R²⁹ are independently at each occurrence a hydrogen atom, an aliphatic radical, an aromatic radical, or a cycloaliphatic radical.

8. The article as defined in claim 4, wherein one or both of the first hydrophobic moiety or the second hydrophobic moiety comprises an organosilane group having a formula (IX), (X), (XI) or (XII):

(R³⁰R³¹R³²Si)₂(R³³R³⁴Si)_d(R³⁵Si)—

 

 

(IX)
(R³⁶R³⁷R³⁸Si)(R³⁹R⁴⁰Si)_f(R⁴¹R⁴²Si)—

 

 

(X)
(R⁴³R⁴⁴R⁴⁵Si)₂(CR⁴⁶R⁴⁷)_d(R⁴⁸Si)—

 

 

(XI)
(R⁴⁹R⁵⁰R⁵¹Si)(CR⁵²R⁵³)_f(R⁵⁴R⁵⁵Si)—

 

 

(XII)

wherein “

d”

is independently at each occurrence an integer from 0 to 50, “

b”

is independently at each occurrence an integer from 1 to 50, and R³⁰ to R⁵⁵ are independently at each occurrence a hydrogen atom, an aliphatic radical, an aromatic radical, or a cycloaliphatic radical.

9. The article as defined in claim 1, wherein the surfactant comprises an organosiloxane having formula (XIII):

(R⁵⁶R⁵⁷R⁵⁸SiO_1/2)(R⁵⁹R⁶⁰SiO_2/2)_j(R₆₀R⁶¹R¹⁰SiO_1/2) 

 

(XIII)

wherein “

j”

is an integer from 0 to 50;

R5f⁶ is a branched aliphatic radical, an aromatic radical, a cycloaliphatic radical, or R⁶²R⁶³R⁶⁴SiR⁶⁵;

R⁵⁷ and R⁵⁸ are independently at each occurrence a hydrogen atom, an aliphatic radical, an aromatic radical, a cycloaliphatic radical, or a R⁵⁶ radical;

R⁵⁹, R⁶⁰, R⁶², R⁶³, and R⁶⁴ are independently at each occurrence a hydrogen atom, an aliphatic radical, an aromatic radical, or a cycloaliphatic radical;

R⁶⁵ is a divalent aliphatic radical, a divalent aromatic radical, or a divalent cycloaliphatic radical;

R⁶⁰ and R⁶¹are independently at each occurrence a hydrogen atom, an aliphatic radical, an aromatic radical, a cycloaliphatic radical, or a R⁵⁶ radical; and

R¹⁰is a polyoxyalkylene having formula (II);

R¹³(C₂H₃R¹¹O)_w(C₃H₆O)_x(C₄H₈O)_yR¹² 

 

(II)

wherein “

w”

, “

y” and

“

z”

are independently an integer from 0 to 20, with the proviso that “

w”

is greater than or equal to 2 and “

w+x+y”

is in a range of from about 2 to about 20;

R¹¹ is a hydrogen atom or an aliphatic radical, R¹² is a hydrogen atom, an aliphatic radical, or a carboxylate; and

R¹¹ is a divalent aliphatic radical having structure (Ill);

—

CH₂—

CH(R¹⁴)(R¹⁵)_zO—

 

 

(III)

wherein R¹⁴ is a hydrogen atom or an aliphatic radical, R¹⁵ is a divalent aliphatic radical, and “

z”

is 0 or 1.

10. The article as defined in claim 1, wherein an aqueous solution of the surfactant has a surface tension in a range of less than about 40 mN/m, at a concentration greater than about 0.1 weight percent.

11. The article as defined in claim 1, wherein a 10 microliter drop of an aqueous solution of the surfactant spreads to a diameter greater than five times as large on a hydrophobic surface as a 10 microliter drop of distilled water on the hydrophobic surface, wherein the diameter is measured 30 seconds after application of the drop to the hydrophobic surface.

12. The article as defined in claim 1, wherein the surfactant is hydrolytically stable in an aqueous solution at a pH in a range of from about 2 to about 10.

13. The article as defined in claim 1, wherein the membrane is formed from a material selected from the group consisting of polyalkene, polyarylene, polyamide, polyester, polysulfone, polyether, polyacrylic, polystyrene, polyurethane, polyarylate, polyimide, polycarbonate, polyphenylene oxide, and cellulosic polymer;

or a substituted derivative of one or more of the foregoing.

14. The article as defined in claim 1, wherein the membrane comprises a halogenated polyalkene.

15. The article as defined in claim 1, wherein the membrane comprises one or both of polyvinylidenefluoride or polytetrafluoroethylene.

16. The article a defined in claim 1, wherein the membrane is expanded, stretched, bubbled, precipitated, perforated, or extracted to form pores that correspond in shape, size, volume, or character to the pore forming method.

17. The article as defined in claim 1, wherein the pores have an average diameter in a range of from about 1 nanometer to about 1000 micrometers.

18. The article as defined in claim 1, wherein the surfactant is operable to render the membrane wetable from a dry ship state.

19. The article as defined in claim 1, wherein a 1 microliter drop of water has a contact angle of less than about 30 degrees on a surface of the article.

20. The article as defined in claim 1, wherein the article has a flow rate of water that is greater than about 1 mL/min-cm at 27 inches Hg pressure differential after 10 wet/dry cycles at room temperature.

21. A method, comprising:

contacting a porous membrane with a surfactant, wherein the surfactant has a capability to function as a superspreader when in solution; and

contacting the membrane with a fluid.

22. The method as defined in claim 21, further comprising mixing the surfactant and the solution to form one or more of a surfactant solution, a surfactant. stabilized emulsion, a surfactant mediated sol-gel, a surfactant mediated gel, or a slurry.

23. The method as defined in claim 22, wherein contacting comprises immersing the membrane in the mixture of the surfactant solution.

24. The method as defined in claim 21, wherein the solution comprises one or more of water, alcohol, fatty acid, ketone, glycol, or diol.

25. The method as defined in claim 21, further comprising removing a solvent from the solution by one or both of heating or of applying a vacuum.

26. The method as defined in claim 25, comprising cycling the membrane through two or more wet/dry cycles after removal of the solvent.

27. The method as defined in claim 21, further comprising flowing the fluid through the membrane at a flow rate that is greater than about 1 mL/min-cm at 27 inches Hg pressure differential at room temperature after 10 wet/dry cycles.

28. The method as defined in claim 21, further comprising flowing the fluid through the membrane pores and separating a chemical species from the solution such that the fluid is enriched with the chemical species on a first side of the membrane and the fluid is depleted of the chemical species on a second side of the membrane.

29. An article, comprising:

a chemically inert, hydrophobic, means for filtering fluid; and

means for hydrophiliphizing a surface of the fluid filtering means.

30. The article as defined in claim 29, wherein the fluid filtering means is porous or perforated.