Carbon nanotube composite structure and method of manufacturing the same

Abstract

Provided are a carbon nanotube structure more excellent in electric conductivity, thermal conductivity, and mechanical strength, and a method of manufacturing the carbon nanotube structure. A carbon nanotube composite structure is characterized by including: a first carbon nanotube structure in which functional groups bonded to plural carbon nanotubes are chemically bonded and mutually cross-linked to construct a network structure; and a second carbon nanotube structure in which functional groups bonded to plural carbon nanotubes are chemically bonded and mutually cross-linked to construct a network structure, the second carbon nanotube structure being combined with the network structure of the first carbon nanotube structure.

1 . A carbon nanotube composite structure comprising: 
 a first carbon nanotube structure in which functional groups bonded to plural carbon nanotubes are chemically bonded and mutually cross-linked to construct a network structure; and    a second carbon nanotube structure in which functional groups bonded to plural carbon nanotubes are chemically bonded and mutually cross-linked to construct a network structure, the second carbon nanotube structure being combined with the network structure of the first carbon nanotube structure.    
     
     
         2 . A carbon nanotube composite structure according to  claim 1 , wherein an average diameter of the carbon nanotubes constituting the first carbon nanotube structure is different from an average diameter of the carbon nanotubes constituting the second carbon nanotube structure.  
     
     
         3 . A carbon nanotube composite structure according to  claim 1 , wherein main carbon nanotubes constituting the first carbon nanotube structure are multi-wall carbon nanotubes, and main carbon nanotubes constituting the second carbon nanotube structure are single-wall carbon nanotubes.  
     
     
         4 . A carbon nanotube composite structure according to  claim 1 , wherein at least one of the first carbon nanotube structure and the second carbon nanotube structure is manufactured by curing a solution containing plural carbon nanotubes to which functional groups are bonded, and by chemically bonding the plural functional groups bonded to the carbon nanotubes to form cross-linked sites.  
     
     
         5 . A carbon nanotube composite structure according to  claim 4 , wherein the cross-linked sites in at least one of the first carbon nanotube structure and the second carbon nanotube structure are structured by cross-linking the plural functional groups with a cross-linking agent in the solution, and the cross-linking agent is not self-polymerizable.  
     
     
         6 . A carbon nanotube composite structure according to  claim 1 , wherein each of the cross-linked sites where plural carbon nanotubes mutually cross-link in at least one of the first carbon nanotube structure and the second carbon nanotube structure has a chemical structure selected from the group consisting of —COO(CH 2 ) 2 OCO—, —COOCH 2 CHOHCH 2 OCO—, —COOCH 2 CH(OCO—)CH 2 OH, and —COOCH 2 CH(OCO—)CH 2 OCO—.  
     
     
         7 . A carbon nanotube composite structure according to  claim 4 , wherein the cross-linked sites in at least one of the first carbon nanotube structure and the second carbon nanotube structure are formed through chemical bonding of the plural functional groups of a same type.  
     
     
         8 . A carbon nanotube composite structure according to  claim 7 , wherein a reaction forming the chemical bonding is one reaction selected from the group consisting of dehydration condensation, a substitution reaction, an addition reaction, and an oxidative reaction.  
     
     
         9 . A carbon nanotube composite structure according to  claim 1 , wherein each of the cross-linked sites where plural carbon nanotubes mutually cross-link in at least one of the first carbon nanotube structure and the second carbon nanotube structure is one cross-linked site selected from the group consisting of —COOCO—, —O—, —NHCO—, —COO—, —NCH—, —NH—, —S—, —O—, —NHCOO—, and —S—S—.  
     
     
         10 . A method of manufacturing a carbon nanotube composite structure, comprising: 
 a first supplying step of supplying a surface of a substrate with a first solution containing plural carbon nanotubes to which functional groups are bonded;    a first cross-linking step of chemically bonding the plural functional groups to form a first carbon nanotube structure in which the plural carbon nanotubes mutually cross-link to construct a network structure;    a second supplying step of supplying the first carbon nanotube structure with a second solution containing plural carbon nanotubes to which functional groups are bonded; and    a second cross-linking step of chemically bonding the plural functional groups in the second solution to form a second carbon nanotube structure in which the plural carbon nanotubes mutually cross-link to construct a network structure, the second carbon nanotube structure being combined with the first carbon nanotube structure.    
     
     
         11 . A method of manufacturing a carbon nanotube composite structure according to  claim 10 , wherein an average diameter of the carbon nanotubes in the first solution is different from an average diameter of the carbon nanotubes in the second solution.  
     
     
         12 . A method of manufacturing a carbon nanotube composite structure according to  claim 10 , wherein main carbon nanotubes in the first solution are multi-wall carbon nanotubes, and main carbon nanotubes in the second solution are single-wall carbon nanotubes.  
     
     
         13 . A method of manufacturing a carbon nanotube composite structure according to  claim 10 , wherein: 
 at least one of the first solution and the second solution contains a cross-linking agent that cross-links the plural functional groups together; and    the cross-linking agent is not self-polymerizable.    
     
     
         14 . A method of manufacturing a carbon nanotube composite structure according to  claim 13 , wherein: 
 each of the functional groups in at least one of the first solution and the second solution is at least one functional group selected from the group consisting of —OH, —COOH, —COOR (where R represents a substituted or unsubstituted hydrocarbon group), —COX (where X represents a halogen atom), —NH 2 , and —NCO; and    the cross-linking agent is capable of prompting a cross-linking reaction with the selected functional groups.    
     
     
         15 . A method of manufacturing a carbon nanotube composite structure according to  claim 13 , wherein: 
 the cross-linking agent is at least one cross-linking agent selected from the group consisting of a polyol, a polyamine, a polycarboxylic acid, a polycarboxylate, a polycarboxylic acid halide, a polycarbodiimide, and a polyisocyanate; and    each of the functional groups in at least one of the first solution and the second solution is capable of prompting a cross-linking reaction with the selected cross-linking agent.    
     
     
         16 . A method of manufacturing a carbon nanotube composite structure according to  claim 13 , wherein: 
 each of the functional groups in at least one of the first solution and the second solution is at least one functional group selected from the group consisting of —OH, —COOH, —COOR (where R represents a substituted or unsubstituted hydrocarbon group), —COX (where X represents a halogen atom), —NH 2 , and —NCO;    the cross-linking agent is at least one cross-linking agent selected from the group consisting of a polyol, a polyamine, a polycarboxylic acid, a polycarboxylate, a polycarboxylic acid halide, a polycarbodiimide, and a polyisocyanate; and    the functional groups and the cross-linking agents are respectively selected for a combination capable of prompting a mutual cross-linking reaction.    
     
     
         17 . A method of manufacturing a carbon nanotube composite structure according to  claim 14 , wherein each of the functional groups is —COOR (where R represents a substituted or unsubstituted hydrocarbon group).  
     
     
         18 . A method of manufacturing a carbon nanotube composite structure according to  claim 17 , wherein the cross-linking agent is a polyol.  
     
     
         19 . A method of manufacturing a carbon nanotube composite structure according to  claim 17 , wherein the cross-linking agent is at least one cross-linking agent selected from the group consisting of glycerin, ethylene glycol, butenediol, hexynediol, hydroquinone, and naphthalenediol.  
     
     
         20 . A method of manufacturing a carbon nanotube composite structure according to  claim 10 , wherein at least one of the first solution and the second solution further contains a solvent.  
     
     
         21 . A method of manufacturing a carbon nanotube composite structure according to  claim 13 , wherein the cross-linking agent also functions as a solvent.  
     
     
         22 . A method of manufacturing a carbon nanotube composite structure according to  claim 10 , wherein a reaction forming the chemical bonding in at least one of the first cross-linking step and the second cross-linking step is a reaction for chemically bonding the plural functional groups of a same type.  
     
     
         23 . A method of manufacturing a carbon nanotube composite structure according to  claim 22 , wherein at least one of the first solution and the second solution further contains an additive that forms the chemical bonding among the plural functional groups of a same type.  
     
     
         24 . A method of manufacturing a carbon nanotube composite structure according to  claim 23 , wherein the reaction is dehydration condensation and the additive is a condensation agent.  
     
     
         25 . A method of manufacturing a carbon nanotube composite structure according to  claim 24 , wherein each of the functional groups is at least one functional group selected from the group consisting of —COOR (where R represents a substituted or unsubstituted hydrocarbon group), —COOH, —COX (where X represents a halogen atom), —OH, —CHO—, and —NH 2 .  
     
     
         26 . A method of manufacturing a carbon nanotube composite structure according to  claim 25 , wherein each of the functional groups is —COOH.  
     
     
         27 . A method of manufacturing a carbon nanotube composite structure according to  claim 24 , wherein the condensation agent is at least one condensation agent selected from the group consisting of sulfuric acid, N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide, and dicyclohexyl carbodiimide.  
     
     
         28 . A method of manufacturing a carbon nanotube composite structure according to  claim 23 , wherein the reaction is a substitution reaction and the additive is a base.  
     
     
         29 . A method of manufacturing a carbon nanotube composite structure according to  claim 28 , wherein each of the functional groups is at least one functional group selected from the group consisting of —NH 2 , —X (where X represents a halogen atom), —SH, —OH, —OSO 2 CH 3 , and —OSO 2 (C 6 H 4 )CH 3 .  
     
     
         30 . A method of manufacturing a carbon nanotube composite structure according to  claim 28 , wherein the base is at least one base selected from the group consisting of sodium hydroxide, potassium hydroxide, pyridine, and sodium ethoxide.  
     
     
         31 . A method of manufacturing a carbon nanotube composite structure according to  claim 22 , wherein the reaction is an addition reaction.  
     
     
         32 . A method of manufacturing a carbon nanotube composite structure according to  claim 31 , wherein each of the functional groups is at least one functional group selected from the group consisting of —OH and —NCO.  
     
     
         33 . A method of manufacturing a carbon nanotube composite structure according to  claim 22 , wherein the reaction is an oxidative reaction.  
     
     
         34 . A method of manufacturing a carbon nanotube composite structure according to  claim 33 , wherein each of the functional groups is —SH.  
     
     
         35 . A method of manufacturing a carbon nanotube composite structure according to  claim 33 , wherein the solution further contains an oxidative reaction accelerator.  
     
     
         36 . A method of manufacturing a carbon nanotube composite structure according to  claim 35 , wherein the oxidative reaction accelerator is iodine.