Nanoporous composites of polymerized lyotropic liquid-crystalline monomers, and hydrophobic polymers

• US 7,090,788 B2
• Filed: 04/24/2003
• Issued: 08/15/2006
• Est. Priority Date: 04/24/2003
• Status: Expired due to Fees

• Current Assignee: Tda Research, Inc.
• Original Assignee: Tda Research, Inc.
• Inventors: Elliott, Brian
• Primary Examiner(s): WU, SHEAN CHIU
• Application Number:
  US10/422,604
• Publication Number:
  US 20040211939A1
• Time in Patent Office: 1,209 Days
• Field of Search: 252/299.01, 252/299.5, 428/1.1, 428/411.1, 428/315.5, 428/500, 428/704, 428/910, 428/323, 428/316.6, 977/897
• US Class Current: 252/299.01
• CPC Class Codes: C09K 19/38 Polymers
• CPC Class Codes: C09K 19/52 characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
• CPC Class Codes: Y10S 428/91 Product with molecular orientation
• CPC Class Codes: Y10S 977/897 Polymerization
• CPC Class Codes: Y10T 428/249978 Voids specified as micro
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers

Abstract

This invention provides composite materials that combine the material properties of hydrophobic polymers with internal structure and order provided by polymerization of lyotropic liquid crystals (LLCs). Composites, particularly nanocomposites, are made by forming a LLC assembly that has hydrophobic regions and hydrophilic regions, combining hydrophobic polymer in the assembly and polymerizing the polymerizable LLC monomers in the assembly. The hydrophobic polymer, polymerized LLC assembly or both can be crosslinked in the composite. Nanoporous composites, particularly those with uniform-sized pores and/or with uniform pores distribution can be prepared in this way. In addition, complex polymers in which a second polymeric material, which may be organic or inorganic, can be introduced into the pores or other structural features of the composite can be prepared. Adding flexible hydrophobic polymers to the LLC assembly increases the flexibility and toughness of the resultant polymerized composite material to provide improved composite materials for use as membranes and in other applications. Hydrophobic polymer addition can also increase the diffusion resistance in the organic phase of the composite. Of particular interest are composites in which the hydrophobic polymer is butyl rubber or related synthetic rubber.

Claims

1. A composite material which comprises:

a polymerized lyotropic liquid crystal assembly having hydrophobic and hydrophilic regions formed by polymerization of a non-polymerized liquid crystal assembly which contains polymerizable lyotropic liquid crystal monomers, and

a hydrophobic polymer in the hydrophobic regions of the lyotropic liquid crystal assembly wherein the hydrophobic polymer is not formed by polymerizing the lyotropic liquid crystal monomers.

2. The composite material of claim 1 wherein the hydrophobic regions of the composite comprise a lyotropic liquid crystal phase swollen with the hydrophobic polymer.

3. The composite material of claim 1 wherein the hydrophobic regions of the composite comprise subregions containing lyotropic liquid crystal phases or lyotropic liquid crystal aggregates and separated subregions of hydrophobic polymer.

4. The composite material of claim 3 wherein at least a portion of the lyotropic liquid crystal phase is swollen with the hydrophobic polymer.

5. The composite material of claim 1 wherein the lyotropic liquid crystal assembly comprises an inverted hexagonal phase.

6. The composite material of claim 1 wherein the lyotropic liquid crystal assembly is an inverted hexagonal phase.

7. The composite material of claim 1 where the polymerizable lyotropic liquid crystal assembly comprises a bi-continuous cubic phase.

8. The composite material of claim 1 where the polymerizable lyotropic liquid crystal assembly is a bi-continuous cubic phase.

9. The composite material of claim 1 wherein the hydrophobic polymer has a molecular weight equal to or greater than 500 Daltons or is comprised of at least 10 monomer repeat units.

10. The composite material of claim 1 where the hydrophobic polymer has a molecular weight equal to or greater than 1000 Daltons or is comprised of at least 20 monomer repeat units.

11. The composite material of claim 1 where the hydrophobic polymer is a linear molecule.

12. The composite material of claim 1 where the hydrophobic polymer is an elastomer.

13. The composite material of claim 1 where the hydrophobic polymer is a synthetic rubber.

14. The composite material of claim 1 where the hydrophobic polymer is butyl rubber.

15. The composite material of claim 1 where the hydrophobic polymer is selected from the group consisting of butyl rubber, poly(propyleneoxide), poly(vinylchloride), poly(propylene), poly(ethylene), chlorinated poly(ethylene), poly(acrylates), poly(methacrylates), poly(lactic acid), poly(ethyleneterphthalates), poly(styrenes) poly(aramides) and combinations thereof.

16. The composite material of claim 1 where the hydrophobic polymer comprises a mixture of at least two different polymers.

17. The composite material of claim 1 which comprises pores.

18. The composite material of claim 1 which comprises nanopores.

19. The composite material of claim 1 which contains water or a polar solvent.

20. The composite material of claim 1 wherein a polymerizable lyotrophic liquid crystal monomer has the formula:

(HY)_z[T(X¹)_y(X²(P)_p)_x]_w

and salts thereof,

where;

HY is a hydrophilic head group;

z is an integer representing the number of hydrophilic head groups;

X²(P)_p is a hydrophobic tail group which contain at least one polymerizable group P;

X² and P on the same lyotrophic liquid crystal monomer may be the same or different;

x is an integer equal to or greater than 1 representing the number of hydrophobic groups carrying polymerizable groups

X¹ is a hydrophobic tail group which does not contain a polymerizable group;

y is zero or an integer equal to or greater than 1 representing the number of hydrophobic groups in the molecule that do not carry a polymerizable group;

P is a polymerizable group;

p is an integer equal to or greater than 1 representing the number of polymerizable groups on a hydrophobic tail,

T is a single bond or a linker group that provides for attachment of one or more hydrophobic tail groups to one or more hydrophilic head groups; and

w is an integer equal to or less than z representing the number of T bonds or groups attached to the z HY groups.

21. The composite material of claim 20 wherein all HY are charged groups.

22. The composite material of claim 20 wherein the HY groups together form one or more zwitterionic groups.

23. The composite material of claim 20 wherein HY groups are selected from the groups consisting of carboxylate, poly(ethyleneoxide), sulfonate, sulfonate ester, sulfonium, phosphonate, phosphonate ester, phosphonium, and ammonium groups.

24. The composite material of claim 20 wherein z is 1.

25. The composite material of claim 24 wherein w is 1.

26. The composite material of claim 20 wherein w is equal to z.

27. The composite material of claim 20 wherein P groups are selected from the group consisting of acrylate, methacrylate, diene, vinyl, halovinyl, styrenes, vinylether, hydroxy groups, epoxy or other oxiranes, halooxirane, dienoyls, diacetylenes, styrenes, terminal olefins, isocyanides, acrylamides, and cinamoyl groups.

28. The composite material of claim 20 wherein P groups are dienes, olefins, acrylate or methacrylate groups.

29. The composite material of claim 20 wherein p is 1.

30. The composite material of claim 20 wherein X² are alkyl or alkenyl chains having from 7 to 24 carbon atoms.

31. The composite material of claim 20 wherein the lyotrophic liquid crystal monomer comprises more than one hydrophobic tail and at least one of the hydrophobic tails contains a polymerizable group and at least one of the hydrophobic tails does not contain a polymerizable group.

32. The composite material of claim 20 wherein T is an aryl group functionalized for attachment of X¹ and X²(P)_p groups.

33. The composite material of claim 20 wherein the polymerizable lyotropic liquid crystal monomers are salts of metal cations.

34. The composite material of claim 20 wherein the polymerizable lyotropic liquid crystal monomers are salts of alkali metals or alkaline earth metals.

35. The composite material of claim 33 wherein the metal cation is selected from copper(I), copper(II), cadmium(II), europium(III), cobalt(II), cobalt(III), silver (I), nickel (I), nickel(II), platinum(II), platinum (IV), gold(I), gold(III), manganese (II), manganese (III), iron (II), iron (III), zinc (II), chromium(II), chromium(III), vanadium(I), and titanium (II) cations.

36. The composite material of claim 1 wherein the polymerizable lyotropic liquid crystal monomers have the structure:

37. The composite material of claim 36 wherein PX² —

is P—

(CH₂)_m—

, where m is an integer ranging from 7 to 24.

38. The composite material of claim 36 wherein PX² —

is C_m1H_2(m1)+1P(CH₂)_m2—

, where m1+m2=m, and m is an integer from 7 to 24.

39. The composite material of claim 36 wherein P is a diene, acrylate, methacrylate or styrene.

40. The composite material of claim 1 wherein the polymerizable LLC monomer has the structure:

41. The composite material of claim 40 wherein P is a diene, acrylate, methacrylate or styrene.

42. The composite material of claim 40 having the structure:

43. The composite material of claim 42 wherein P is an acrylate group.

44. The composite material of claim 1 wherein the lyotropic liquid crystal monomer has the structure:

45. The composite material of claim 44 wherein P-X² is P-(CH₂)_m—

, where m is an integer ranging from 7 to 24, and X¹ is CH₃—

(CH₂)_n—

, where n is an integer ranging from 7 to 24.

46. The composite material of claim 44 wherein R and R′

are alkyl groups.

47. The composite material of claim 44 wherein PX² is a C_m1H_2(m1)+1P(CH₂)_m2—

, where m1+m2 =m, and m is an integer ranging from 7 to 24.

48. The composite material of claim 44 wherein P is a diene.

49. The composite material of claim 1 wherein the polymerizable lyotropic liquid crystal monomer has the structure:

50. The composite material of claim 49 wherein P-X² is P-(CH₂)_m—

, where m is an integer ranging from 7 to 24, or a C_m1H_2(m1)+1P(CH₂)_m2—

group, where m1+m2 =m, and m is an integer ranging from 7 to 24.

51. The composite material of claim 49 wherein R, R′

and R″

are alkyl groups.

52. The composite material of claim 49 wherein P is a diene.

53. The composite material of claim 1 wherein the polymerizable lyotropic liquid crystal monomer has the structure:

54. The composite structure of claim 53 wherein P is a diene, acrylate, methacrylate, styrene or vinyl group.

55. The composite material of claim 53 wherein HY-L-HY is N⁺(R)(R′

)(R″

)-(CH₂)_p—

P⁻

(O₃)—

O—

where R, R′

, R″

are, independently, hydrogens or alkyl groups, and p is an integer ranging from 2 to 8.

56. The composite material of claim 1 wherein the polymerizable lyotropic liquid crystal monomer has the structure:

57. The composite material of claim 56 wherein P are dienes.

58. The composite material of claim 56 wherein X² are straight-chain alkyl or branched chain alkyl groups having from 7 to 24 carbon atoms.

59. The composite material of claim 56 wherein HY-L-HY is N⁺(R)(R′

)(R″

)—

(CH₂)_p-P⁻

(O₃)—

O—

where R, R′

, R″

are, independently, hydrogens or alkyl groups, and p is an integer ranging from 2 to 8.

60. The composite material of claim 1 wherein the polymerized lyotropic liquid crystal assembly, the hydrophobic polymer, or both are crosslinked.

61. The composite material of claim 1 wherein the polymerized lyotropic liquid crystal assembly further comprises lyotropic liquid crystals which do not carry polymerizable groups.

62. The composite material of claim 1, wherein the hydrophilic regions of the polymerized liquid crystal assembly further comprise a second polymeric material which is different from the hydrophilic polymer and the polymerized liquid crystal assembly.

63. The composite material of claim 1 which comprises pores, wherein the pores comprise a second polymeric material which is different from the hydrophilic polymer and the polymerized lyotrophic liquid crystal assembly.

64. The composite material of claim 63 wherein the pores are nanopores.

65. The composite material of claim 1 wherein the polymerizable lyotropic liquid crystal monomer is sodium 3,4,5-tris(ω

- acryloyloxyundecyloxy)benzoate.

66. The composite material of claim 65 wherein the hydrophobic polymer is butyl rubber.

67. The composite material of claim 66 wherein the butyl rubber is vulcanized.

68. A composite material of claim 1 further comprising a second polymeric material which is different from the hydrophobic polymer and the polymerized lyotrophic liquid crystal assembly which is introduced into hydrophilic regions of the composite.

69. The composite material of claim 68 wherein the second polymeric material is introduced into pores of the composite.

70. The composite of claim 68 wherein the second polymeric material is selected from the group consisting of poly(acrylic acid), poly(acrylamide), poly(vinyl alcohol), poly(hydroxyethyl methacrylate), poly(N-vinyl pyrrolidinone), poly(thiophene), poly(ethylene glycol), poly(ethylenedioxythiophene), poly(p-xylylenetetrahydrothiophene chloride), poly(p-xylylene dimethylsulfonium chloride), poly(p-xylylenetetrahydrothiofuranyl chloride), poly(p-phenylenevinylene), and copolymers thereof.

71. The composite of claim 68 wherein the second polymeric material is an inorganic polymer.

80. A porous membrane comprising the composite material of claim 1.

81. The membrane of claim 80 comprising a thin film of the composite material on a microporous membrane support.

82. The membrane of claim 81 wherein the microporous membrane support is a polyethersulfone microporous membrane support.

83. A porous membrane prepared from the composite material of claim 1.

84. A nanoporous membrane comprising the composite of claim 1.

85. A nanoporous membrane prepared from the composite of claim 1.

86. A nanoporous membrane of claim 85 wherein the hydrophobic polymer is butyl rubber.

87. A nanoporous membrane of claim 86 wherein the polymerizable lyotropic liquid crystal assembly forms an inverted hexagonal phase.

88. The nanoporous membrane of claim 87 wherein the polymerizable lyotropic liquid crystal monomer is sodium 3,4,5-tris(ω

- acryloyloxyundecyloxy)benzoate.

97. The composite material of claim 36 wherein X² is a straight-chain or branched alkyl group.

98. The composite material of claim 36 wherein L is an —

(CH₂)_m—

group, where m is an integer from 1 to about 10, or a —

(CH₂)_p—

O—

(CH₂)_q—

group, where p and q are 1 or 2.

99. The composite material of claim 98 wherein W is phosphorous.

100. The composite material of claim 99 wherein P is a diene.

101. The composite material of claim 100 wherein X² is an —

(CH₂)_m—

group where m is an integer ranging from 7 to 24.

102. The composite material of claim 101 where m is 10.

103. The composite material of claim 102 wherein R and R′

are alkyl groups.

104. The composite material of claim 98 wherein L is a —

(CH₂)₆—

group.

105. The composite material of claim 36 wherein the hydrophobic polymer is an elastomer.

106. The composite material of claim 105 wherein the hydrophobic polymer is butyl rubber.

107. A nanoporous membrane comprising the composite material of claim 36.

108. The membrane of claim 81 wherein the microporous membrane support is a polyethylene microporous membrane support.

109. The composite material of claim 20 wherein z and w are 1, y is 0, and x is 1.

110. The composite material of claim 20 wherein the polymerizable lyotropic liquid crystal monomers are salts of Li(I), Na(I), K(I) or Sr(II).

72. A lyotropic liquid crystal assembly having hydrophobic and hydrophilic regions which comprises one or more polymerizable lyotropic liquid crystal monomers, which on polymerization form a lyotropic liquid crystal assembly, and one or more hydrophobic polymers, which are not formed by polymerizing the lyotrophic liquid crystal monomers, in the hydrophobic regions of the assembly.

73. The lyotropic liquid crystal assembly of claim 72 further comprising one or more non-polymerizable lyotropic liquid crystals in the assembly.

74. The lyotropic liquid crystal assembly of claim 72 further comprising water or a polar solvent.

75. The lyotropic liquid crystal assembly of claim 72 comprising a lyotropic liquid crystal phase.

76. The lyotropic liquid crystal assembly of claim 75 wherein the lyotropic liquid crystal phase is an inverted hexagonal phase.

77. The lyotropic liquid crystal assembly of claim 75 wherein the lyotropic liquid crystal phase is a bi-continuous cubic phase.

78. The assembly of claim 72 further comprising photoinitiator molecules which can induce chemical reactions upon exposure to light.

79. The assembly of claim 72 further comprising molecules that can induce crosslinking reactions.

89. A method for making a composite of polymerizable lyotropic liquid crystals and a hydrophobic polymer which comprises the steps:

(a) combining a polymerizable lyotrophic liquid crystal monomer with a hydrophobic polymer and optionally an aqueous or polar solvent, the lyotrophic liquid crystal monomer present in an amount relative to the hydrophobic polymer and the aqueous or polar solvent present in an amount such that at least a portion of the lyotrophic liquid crystal monomer forms a lyotrophic liquid crystal phase, lyotrophic liquid crystal aggregates or both; and

(b) polymerizing the polymerizable lyotrophic liquid crystal monomer in the combination of step (a) to form a polymerized lyotrophic liquid crystal assembly thereby making the composite material.

90. The method of claim 89 where the hydrophobic polymer is subsequently crosslinked.

91. The method of claim 89 wherein in step (a) the polymerizable lyotropic liquid crystal monomer, a hydrophobic polymer and a solvent that will dissolve the hydrophobic polymer are combined and further comprising the steps after step (a) and before step (b) of

heating the combination of step (a) to a temperature above the clearing point of the polymerizable lyotropic liquid crystal monomer, cooling the combination and removing solvent from the combination to form a lyotropic liquid crystal assembly.

92. The method of claim 91 wherein the hydrophobic polymer is subsequently crosslinked.

93. The method of claim 89 further comprising the step of introducing a second polymeric material into pores formed in the composite material after polymerization of the lyotropic liquid crystal monomer.

94. The method of claim 91 further comprising the step of introducing a second polymeric material into pores formed in the composite material after polymerization of the lyotropic liquid crystal monomer.

95. The method of claim 89 wherein the composite material is a complex composite which comprises the steps:

(a) combining one or more polymerizable lyotrophic liquid crystal monomers, one or more hydrophobic polymers, one or more hydrophilic monomers and optionally an aqueous or polar solvent, the lyotrophic liquid crystal monomer present in an amount relative to the hydrophobic polymer and the aqueous or polar solvent present in an amount such that at least a portion of the lyotrophic liquid crystal monomer forms an lyotrophic liquid crystal assembly, the hydrophobic polymer within hydrophobic regions of the lyotrophic liquid crystal assembly and the hydrophilic monomers within hydrophilic regions of the lyotrophic liquid crystal assembly,

(b) polymerizing the polymerizable lyotrophic liquid crystal monomer in the combination of step (a) to form a polymerized lyotrophic liquid crystal assembly, and

(c) polymerizing the hydrophilic monomers in the combination of step(a) to form a second polymeric material within hydrophilic regions of the lyotrophic liquid crystal assembly

to thereby form a complex composite material.

96. The method of claim 95 further comprising the steps of crosslinking the hydrophobic polymer, the polymerized lyotrophic liquid crystal assembly, the second polymer or any combination thereof.