CONTINUOUS PROCESS FOR THE PRODUCTION OF NANOSTRUCTURES INCLUDING NANOTUBES

• US 20160083256A1
• Filed: 09/18/2015
• Published: 03/24/2016
• Est. Priority Date: 05/19/2006
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Hart, Anastasios John, Wardle, Brian L., Garcia, Enrique J., Slocum, Alexander H.
• Granted Patent: US 9,394,175 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 23/745 Iron
• CPC Class Codes: B82B 1/00 Nanostructures formed by manipulation of individual atoms or molecules, or limited collections of atoms or molecules as discrete units
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 2202/08 Aligned nanotubes
• CPC Class Codes: C01B 32/158 Carbon nanotubes
• CPC Class Codes: C01B 32/16 Preparation
• CPC Class Codes: C01B 32/162 characterised by catalysts
• CPC Class Codes: C01B 32/164 involving continuous processes
• CPC Class Codes: C01B 32/18 Nanoonions; Nanoscrolls; Nanohorns; Nanocones; Nanowalls
• CPC Class Codes: C08K 3/041 Carbon nanotubes
• CPC Class Codes: D01F 9/127 by thermal decomposition of hydrocarbon gases or vapours or other carbon-containing compounds in the form of gas or vapour, e.g. carbon monoxide, alcohols
• CPC Class Codes: D01F 9/133 Apparatus therefor
• CPC Class Codes: D06M 11/74 with carbon or graphite; with carbides; with graphitic acids or their salts
• CPC Class Codes: D06M 23/08 Processes in which the treating agent is applied in powder or granular form adhesives for multi-layer textile fabrics D06M17/00
• CPC Class Codes: Y02P 20/582 Recycling of unreacted starting or intermediate materials
• CPC Class Codes: Y02P 20/584 Recycling of catalysts
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/843 Gas phase catalytic growth, i.e. chemical vapor deposition

Abstract

The present invention provides methods for uniform growth of nanostructures such as nanotubes (e.g., carbon nanotubes) on the surface of a substrate, wherein the long axes of the nanostructures may be substantially aligned. The nanostructures may be further processed for use in various applications, such as composite materials. For example, a set of aligned nanostructures may be formed and transferred, either in bulk or to another surface, to another material to enhance the properties of the material. In some cases, the nanostructures may enhance the mechanical properties of a material, for example, providing mechanical reinforcement at an interface between two materials or plies. In some cases, the nanostructures may enhance thermal and/or electronic properties of a material. The present invention also provides systems and methods for growth of nanostructures, including batch processes and continuous processes.

Claims

1. A method of growing nanostructures, comprising:

exposing a first portion of a porous growth substrate, with a surface on a first side of the porous growth substrate comprising a catalyst material, to a set of conditions selected to cause catalytic formation of nanostructures on the surface, wherein a nanostructure precursor material used in the formation of the nanostructures is transported from a second side of the porous growth substrate to the first side of the porous growth substrate;

while exposing the first portion of the growth substrate to the set of conditions, removing nanostructures from a second portion of the surface of the growth substrate; and

repeating the exposing and removing acts with said growth substrate at least one time.

3. A method as in claim 1, wherein the nanostructure is a nanotube.

4. A method as in claim 1, wherein the nanostructure is a carbon nanotube.

5. A method as in claim 1, wherein the act of removing comprises removing the nanostructures without attaching the nanostructures to a receiving substrate.

7. A method as in claim 1, wherein the act of removing comprises application of a mechanical tool, mechanical vibration, a chemical reagent, and/or heat to the nanostructures and/or the surface of the growth substrate.

10. A method as in claim 1, wherein the growth substrate is a cylindrical substrate.

12. A method as in claim 1, wherein the growth substrate comprises alumina, silicon, carbon, a ceramic, and/or a metal.

19. A method as in claim 1, wherein the act of exposing comprises flowing the nanostructure precursor material through the porous growth substrate.

2. (canceled)

6. (canceled)

8-9. -9. (canceled)

11. (canceled)

13-18. -18. (canceled)

20-48. -48. (canceled)

49. A method of growing nanostructures, comprising:

exposing a first portion of a growth substrate with a surface comprising a first catalyst material to a first set of conditions selected to cause catalytic formation of nanostructures on the surface; and

while exposing the first portion of the growth substrate to the first set of conditions, treating a second portion of the growth substrate to a second set of conditions selected to reactivate catalyst material on a surface of the second portion of the growth substrate.

50. A method as in claim 49, wherein the nanostructure is a nanofiber.

51. A method as in claim 49, wherein the nanostructure is a nanotube.

52. A method as in claim 49, wherein the nanostructure is a carbon nanotube.

53. A method as in claim 49, further comprising removing the nanostructures from at least a portion of the surface of the growth substrate.

64. A method as in claim 49, wherein the growth substrate is porous.

68. A method as in claim 64, wherein the act of exposing comprises flowing a nanostructure precursor material through the porous growth substrate.

69. A method as in claim 68, wherein the nanostructure precursor material comprises a hydrocarbon.

70. A method as in claim 64, wherein the act of exposing comprises flowing a chemical species through the porous growth substrate to treat the catalyst material.

73. A method as in claim 70, wherein the chemical species reduces or oxidizes the catalyst material after growth of the nanostructures.

87. A method as in claim 49, wherein the nanostructures are arranged on and/or in the surface, such that the long axes of the nanostructures are substantially aligned and non-parallel to the surface.

88. A method as in claim 49, further comprising adding one or more support materials to the nanostructures.

158. A method as in claim 49, wherein the nanostructure is a nanowire.

54-63. -63. (canceled)

65-67. -67. (canceled)

71-72. -72. (canceled)

74-86. -86. (canceled)

89-94. -94. (canceled)

95. A method of growing nanostructures, comprising:

exposing a growth substrate with a surface comprising a catalyst material to a first set of conditions selected to cause catalytic formation of nanostructures on the surface;

removing nanostructures from the surface of the growth substrate; and

treating the growth substrate to a second set of conditions selected to reactivate the catalyst material.

96. A method as in claim 95, wherein the nanostructure is a nanofiber.

97. A method as in claim 95, wherein the nanostructure is a nanotube.

98. A method as in claim 95, wherein the nanostructure is a carbon nanotube.

104. A method as in claim 95, wherein the growth substrate is a cylindrical substrate.

109. A method as in claim 95, wherein the growth substrate is porous.

113. A method as in claim 109, wherein the act of exposing comprises flowing a nanostructure precursor material through the porous growth substrate.

114. A method as in claim 113, wherein the nanostructure precursor material comprises a hydrocarbon.

115. A method as in claim 109, wherein the act of exposing comprises flowing a chemical species through the porous growth substrate to treat the catalyst material.

117. A method as in claim 115, wherein the chemical species re-activates the catalyst material after growth of the nano structures.

118. A method as in claim 115, wherein the chemical species reduces or oxidizes the catalyst material after growth of the nanostructures.

132. A method as in claim 95, wherein the nanostructures are arranged on and/or in the surface, such that the long axes of the nanostructures are substantially aligned and non-parallel to the surface.

133. A method as in claim 95, further comprising adding one or more support materials to the nanostructures, prior to the act of removing.

159. A method as in claim 95, wherein the nanostructure is a nanowire.

99-103. -103. (canceled)

105-108. -108. (canceled)

110-112. -112. (canceled)

116. (canceled)

119-131. -131. (canceled)

134-157. -157. (canceled)