Selective placement of carbon nanotubes via coulombic attraction of oppositely charged carbon nanotubes and self-assembled monolayers

Patent metadata

Field	Value
Publication number	US-9643926-B2
Application number	US-201615001774-A
Country	US
Kind code	B2
Filing date	Jan 20, 2016
Priority date	Sep 29, 2011
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A method of forming a structure having selectively placed carbon nanotubes, a method of making charged carbon nanotubes, a bi-functional precursor, and a structure having a high density carbon nanotube layer with minimal bundling. Carbon nanotubes are selectively placed on a substrate having two regions. The first region has an isoelectric point exceeding the second region's isoelectric point. The substrate is immersed in a solution of a bi-functional precursor having anchoring and charged ends. The anchoring end bonds to the first region to form a self-assembled monolayer having a charged end. The substrate with charged monolayer is immersed in a solution of carbon nanotubes having an opposite charge to form a carbon nanotube layer on the self-assembled monolayer. The charged carbon nanotubes are made by functionalization or coating with an ionic surfactant.

First claim

What is claimed is:

1. A structure having a carbon nanotube (CNT) layer, the structure comprising:
a substrate having a first region arranged adjacent to and in contact with a second region, the first region comprising a metal oxide, the second region comprising a non-metal oxide, and the first region having a first isoelectric point that is greater than a second isoelectric point of the second region;
a self-assembled monolayer arranged only on the first region, the self-assembled monolayer comprising a precursor molecule comprising a first functional group to anchor the precursor molecule to the substrate and a second functional group having a first ionic charge moiety on a surface of the self-assembled monolayer; and
a CNT layer on the self-assembled monolayer, each CNT of the CNT layer comprising a second ionic charge moiety that bonds to the first ionic charge moiety;
wherein the CNT layer has a density exceeding 1 CNT per square micron, and top surfaces of the second region of the substrate remaining exposed.

2. The structure of claim 1 , wherein the CNT layer has a density of bundled CNTs of less than 1 CNT bundle per square micron.

Assignees

• IBM

Inventors

• Afzali-Ardakani Ali
• Park Hongsik
• Tulevski George S

Classifications

• H10D62/122

  oriented at angles to substrates, e.g. perpendicular to substrates · CPC title

• C07D213/76

  to which a second hetero atom is attached (nitro radicals C07D213/61) · CPC title

• H01L29/0676

  Electricity · mapped topic

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C07D213/79 Primary

  Acids; Esters · CPC title