Nanocomposite, nanocomposite electrolyte membrane and fuel using the same

• US 20070072982A1
• Filed: 06/02/2006
• Published: 03/29/2007
• Est. Priority Date: 09/24/2005
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Choi, Yeong-suk, Kim, Hae
• Granted Patent: US 7,652,089 B2
• Time in Patent Office: Days
• US Class Current: 524/445
• CPC Class Codes: C08K 9/04 Ingredients treated with organic substances treated with macromolecular compounds C08K9/08
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A nanocomposite including: a sulfonated polysulfone and a nonmodified clay dispersed in the sulfonated polysulfone, the nonmodified clay having a layered structure, and the nonmodified clay being intercalated with the sulfonated polysulfone, or the layers of the layered structure being exfoliated, a nanocomposite electrolyte membrane and a fuel cell using the same. In the nanocomposite, a nanoscale amount of the nonmodified clay, which has a layered structure, is dispersed in sulfonated polysulfone having excellent ionic conductivity. Thus, the nanocomposite has excellent ionic conductivity and mechanical properties. The nanocomposite electrolyte membrane formed using this nanocomposite has an improved ability to suppress permeation of polar organic fuels, such as methanol, while maintaining appropriate ionic conductivity. In addition, the fuel cell with the nanocomposite electrolyte membrane can effectively prevent crossover of methanol used as a fuel, thereby providing improved working efficiency and an extended lifespan.

Claims

1. A nanocomposite comprising:

a sulfonated polysulfone; and

a nonmodified clay dispersed in the sulfonated polysulfone, the nonmodified clay having a layered structure, and the nonmodified clay being intercalated with the sulfonated polysulfone, or the layers of the layered structure being exfoliated.

2. The nanocomposite of claim 1, wherein the sulfonated polysulfone is represented by formula 1 below.

3. The nanocomposite of claim 2, wherein the sulfonated polysulfone is represented by formula 2 below.

4. The nanocomposite of claim 1, wherein both end portions of the sulfonated polysulfone are end-capped by a clay modifier to provide substitutability with the clay.

5. The nanocomposite of claim 1, wherein the clay modifier is selected from the group consisting of:

2-acetamidophenol, 3-acetamidophenol, 2,6-di-tert-butyl-4-methylphenol, 3-ethylphenol, 2-amino-4-chlorophenol, 6-amino-2,4-dichloro-3-methylphenol, 4-amino-3-methylphenol, 2-amino-3-nitrophenol, 2-aminophenol, 2-sec-butylphenol, 3-aminophenol, 3-diethylaminophenol, 4,4′

-sulfonyldiphenol, 2-methyl-3-nitrophenyl, 3-tert-butylphenol, 2,3-dimethoxyphenol, 4-amino-2,5-dimethylphenol, 2,6-dimethyl-4-nitrophenol, 4-sec-butylphenol, 4-isopropylphenol, 2-amino-4-tert-butylphenol, 2-tertbutyl-4-methylphenol, 4-tert-butyl-2-methylphenol, 4-tert-butylphenol, 2-amino-5-nitrophenol, 5-isopropyl-3-methylphenol, 4-(methylamino)phenol sulfate, 3-methoxyphenol, 3,5-dimethylthiophenol, 3,5-dimethylphenol, 2-aminophenol, 4-aminophenol, 3-(N,N′

-diethylamino)-phenol, 2,6-dimethoxyphenol, 4-acetaminophenol, 2-amino-4-methylphenol, 2,5-dimethylphenol, 2-ethylphenol, 4-ethylphenol, and a mixture thereof.

6. The nanocomposite of claim 1, wherein the nonmodified clay is smectite-based clay.

7. The nanocomposite of claim 6, wherein the smectite-based clay comprises at least one material selected from the group consisting of montmorillonite, bentonite, saponite, beidellite, nontronite, hectorite, and stevensite.

8. The nanocomposite of claim 1, wherein a number-average molecular weight of the nanocomposite is 10,000 and a weight-average molecular weight of the nanocomposite is 20,000.

9. A method of manufacturing the nanocomposite of claim 1, comprising mixing the nonmodified clay, a first polymerized monomer for forming the sulfonated polysulfone, a second polymerized monomer for forming the sulfonated polysulfone, and a diol compound to perform a polymerization reaction after a heat treatment.

10. The method of claim 9, wherein the sulfonated polysulfone is represented by formula 1 below.

11. The method of claim 9, wherein the sulfonated polysulfone is represented by formula 2 below.

12. The method of claim 9, further comprising:

removing water generated under reflux at a polymerization temperature of 100-160°

C.; and

performing a polymerization reaction after heating at a temperature of 140-195°

C.

13. The method of claim 9, further comprising

adding a clay modifier to the mixture of the nonmodified clay, the first polymerized monomer for forming the sulfonated polysulfone, and the second polymerized monomer for forming the sulfonated polysulfone.

14. A method of manufacturing a nanocomposite of claim 1, comprising:

mixing a first polymerized monomer for forming the sulfonated polysulfone, a second polymerized monomer for forming the sulfonated polysulfone, and a diol compound to perform a condensation polymerization reaction after heat treatment; and

adding the nonmodified clay to the resultant obtained from the condensation polymerization reaction and mixing.

15. The method of claim 14, wherein the sulfonated polysulfone is represented by formula 1 below.

16. The method of claim 14, wherein the sulfonated polysulfone is represented by formula 2 below.

17. The method of claim 14, further comprising:

adding a clay modifier to the resultant obtained from the condensation polymerization reaction, prior to adding the nonmodified clay.

18. The method of claim 14, further comprising:

removing water generated under reflux at a polymerization temperature of 100-160°

C.; and

performing a polymerization reaction after heating at a temperature of 140-195°

C.

19. The method of claim 14, wherein the first polymerized monomer is a halide compound as represented by Formula 3 below.

20. The method of claim 14, wherein the second polymerized monomer is a halide compound as represented by Formula 4 below.

21. The method of claim 14, wherein the diol compound is represented by Formula 5 below.

27. A nanocomposite electrolyte membrane comprising the nanocomposite of claim 1.

28. A nanocomposite electrolyte membrane comprising the nanocomposite of claim 2.

29. A fuel cell comprising:

a cathode;

an anode; and

an electrolyte membrane interposed between the cathode and the anode, the electrolyte membrane being a nanocomposite electrolyte membrane including the nanocomposite of claim 1.

30. The fuel cell of claim 29, wherein the electrolyte membrane is a nanocomposite electrolyte membrane including the nanocomposite of claim 2.

31. The fuel cell of claim 29, wherein the electrolyte membrane is a nanocomposite electrolyte membrane including the nanocomposite of claim 3.

22. A method of manufacturing a nanocomposite comprising:

dissolving a sulfonated polysulfone with a solvent to prepare a sulfonated polysulfone solution;

dispersing a clay with a dispersion medium to prepare a clay dispersed solution; and

mixing the sulfonated polysulfone solution and the clay dispersed solution.

23. The method of claim 22, wherein the clay dispersed solution is manufactured at a heating temperature of 40-90°

C.

24. The method of claim 22, wherein the sulfonated polysulfone is a compound represented by formula 1 below:

25. The method of claim 22, wherein the sulfonated polysulfone is obtained from the polymerization reaction of a first polymerized monomer for forming the sulfonated polysulfone, a second polymerized monomer for forming the sulfonated polysulfone, and a diol compound.

26. The method of claim 22, wherein a clay modifier is added to the polymerization reaction.

32. A nanocomposite comprising:

a nanoscale amount of a nonmodified clay having a layered structure; and

a sulfonated polysulfone, wherein the nonmodified clay is dispersed in the sulfonated polysulfone.

33. A nanocomposite electrolyte membrane comprising the nanocomposite of claim 32.

34. A fuel cell comprising:

a cathode;

an anode; and

an electrolyte membrane interposed between the cathode and the anode, the electrolyte membrane being a nanocomposite electrolyte membrane including the nanocomposite of claim 32.

35. The fuel cell of claim 34, further comprising a polar organic fuel, wherein crossover of the polar organic fuel is suppressed by the nanocomposite electrolyte membrane.

36. A method of manufacturing a nanocomposite, comprising mixing a nonmodified clay, a first polymerized monomer for forming a sulfonated polysulfone, a second polymerized monomer for forming the sulfonated polysulfone, and a diol compound to perform a polymerization reaction after a heat treatment.

37. A method of manufacturing a nanocomposite, comprising:

mixing a first polymerized monomer for forming a sulfonated polysulfone, a second polymerized monomer for forming the sulfonated polysulfone, and a diol compound to perform a condensation polymerization reaction after heat treatment; and

adding a nonmodified clay to the resultant obtained from the condensation polymerization reaction and mixing.