Nanotube Structures, Materials, and Methods

Abstract

Nanotube structures and methods for forming nanotube structures are disclosed. The methods include forming nanotubes such that they are associated with a surface of a substrate and compressing at least a portion of the nanotubes. In some embodiments, the nanotubes may be dimensionally constrained in one direction while being compressed in another direction. Compressing at least a portion of the nanotubes may comprise stamping an impression into a surface of the nanotubes, at least a portion of which is retained when the stamp is removed. In some embodiments, the nanotubes may be aligned with respect to one another and to the surface of the substrate and may extend in a direction that is, for example, normal to the substrate.

1 . A method for making a nanotube structure comprising:
 forming nanotubes such that they are associated with a surface of a substrate; and   applying a compressive force to at least a portion of the nanotubes in at least one direction.   
     
     
         2 . The method of  claim 1 , wherein the nanotubes comprise carbon nanotubes. 
     
     
         3 . The method of  claim 1 , further comprising applying a catalyst onto the surface prior to the nanotube forming. 
     
     
         4 . The method of  claim 1 , wherein the compressive force is applied in a dimension normal or about normal to the substrate surface. 
     
     
         5 . The method of  claim 1 , wherein the compressive force is applied in a direction parallel or about parallel to the substrate surface. 
     
     
         6 . The method of  claim 5 , wherein the compressive force causes at least a portion of the nanotubes to dissociate from the substrate surface. 
     
     
         7 . The method of  claim 1 , wherein the compressive force comprises plurality of compressive forces, each applied from a different direction relative to the substrate surface. 
     
     
         8 . The method of  claim 1 , further comprising dislodging the nanotube structure from the surface using a solvent. 
     
     
         9 . The method of  claim 1 , wherein applying a compressive force to at least a portion of the nanotubes comprises applying the compressive force to substantially the entirety of a surface of the nanotubes. 
     
     
         10 . The method of  claim 1 , further comprising constraining the nanotubes in at least one direction while applying the compressive force in another direction. 
     
     
         11 . The method of  claim 1 , wherein applying the compressive force to at least a portion of the nanotubes comprises applying the compressive force selectively to the nanotubes to create one or more surface features on a surface of the nanotubes. 
     
     
         12 . A method for making a nanotube structure comprising:
 forming nanotubes such that they are associated with a surface of a substrate;   impressing a stamp having a stamp surface upon at least a portion of the nanotubes to make an impression in at least the portion of the nanotubes; and   removing the stamp from the portion of the nanotubes;   wherein the portion of the nanotubes retains at least a portion of the impression.   
     
     
         13 . The method of  claim 12 , wherein the stamp has one or more surface features, and the impression comprises at least a partial impression of one of the one or more surface features. 
     
     
         14 . The method of  claim 13 , wherein the nanotubes are substantially aligned with respect to one another and with respect to the surface of the substrate. 
     
     
         15 . The method of  claim 14 , wherein the nanotubes extend in a direction essentially normal to the surface of the substrate. 
     
     
         16 . The method of  claim 12 , further comprising, before the impressing, removing at least a portion of the nanotubes from the surface of the substrate. 
     
     
         17 . The method of  claim 12 , wherein the impressing is performed with the nanotubes at least partially attached to the surface. 
     
     
         18 . A nanotube structure produced by a process comprising:
 forming nanotubes on a surface of a substrate; and   applying a compressive force to at least a portion of the nanotubes to form the nanotube structure;   wherein the nanotube structure is denser and smaller in at least one dimension than the nanotubes.   
     
     
         19 . The nanotube structure of  claim 18 , wherein the nanotube structure is produced by a process further comprising applying a second compressive force in a second direction, and the nanotube structure is denser and smaller in at least two dimensions than the nanotubes. 
     
     
         20 . The nanotube structure of  claim 18 , wherein the nanotube structure comprises two or more connected nanotube structures, each one denser and smaller in at least one dimension than the nanotubes from which it was formed. 
     
     
         21 . The nanotube structure of  claim 18 , wherein the nanotube structure is formed by a process comprising applying a compressive force selectively to portions of the nanotubes, such that the nanotube structure has an impressed or embossed pattern on at least one surface.