Home | This Week's Contents  |  C&EN ClassifiedsSearch C&EN Online

 
Related Stories
Nanotechnology Special Report
[C&EN, Oct. 16, 2000]

Nanotechnology
[C&EN Archive]

E-mail this article to a friend
Print this article
E-mail the editor
 
 
 
 
 
 
 Table of Contents
 C&EN Classifieds
 News of the Week
 Cover Story
 Editor's Page
 Business
 Government & Policy
 Science/Technology
 Concentrates
  Business
  Government & Policy
  Science/Technology
 Education
 ACS News
 Calendars
 Books
 Digital Briefs
 ACS Comments
 Career & Employment
 Special Reports
 Letters
 Newscripts
 Nanotechnology
 What's That Stuff?
 Pharmaceutical Century

 Hot Articles
 Safety  Letters
 Chemcyclopedia

 Back Issues

 How to Subscribe
 Subscription Changes
 About C&EN
 Copyright Permission
 E-mail webmaster
NEWS OF THE WEEK
NANOCHEMISTRY
February 4,
 2002
Volume 80, Number 5
CENEAR 80 5 p. 12
ISSN 0009-2347
[Previous Story] [Next Story]

HOW TO MAKE THE INSOLUBLE SOLUBLE
Attaching large organic groups is key to unclumping nanotubes

ELIZABETH WILSON

If only they would swim freely in solution, nanotubes might easily realize their enormous potential for electronics and materials. But the chicken-wire-like carbon cylinders are notoriously insoluble: They tend to clump together in unmanageable globby ropes.

Chemists have tried to address the problem with everything from brute force--where tubes are throttled loose with high-intensity ultrasound in a process known as sonication--to functionalization with chemical groups that keep the tubes from associating.

The functionalization approach gets a dramatic boost with new work by organic chemistry professor Maurizio Prato and colleagues at the University of Trieste, in Italy; the University of Notre Dame; and the University of Erlangen-Nürnberg, in Germany. The group reports that a method they've developed for attaching organic groups to nanotubes makes the tubes soluble to the tune of 50 mg per mL--much higher than previously reported. In addition, the researchers say, the tubes remain in solution in water and a number of organic solvents indefinitely [J. Am. Chem. Soc., 124, 760 (2002)].

"I've never seen [nanotubes] with a solubility as high as this," says chemistry professor James M. Tour at Rice University. "That's really amazing."

Several years ago, Prato and his group developed a method that's been widely used to functionalize fullerenes, which they have now extended to nanotubes. This so-called Prato reaction generates reactive azomethine ylides that can attack the nanotubes through the condensation of an a-amino acid and an aldehyde.

The nature of the attached groups, which are quite large, is likely key to solubility, as the same reaction done with small organic groups yielded nanotubes that were not very soluble, Prato says.

Tour and his group are now trying to replicate the new work, in part for "the joy of saying, 'Voilà! We've got it, too.' "


FUNCTIONALIZED Carbon nanotubes with organic appendages are highly soluble.

COURTESY OF MAURIZIO PRATO & PAOLO BRAIUCA

[Previous Story] [Next Story]



Top


Chemical & Engineering News
Copyright © 2002 American Chemical Society


Home | Table of Contents | News of the Week | Cover Story
Business | Government & Policy | Science/Technology
Chemical & Engineering News
Copyright © 2002 American Chemical Society - All Right Reserved
1155 16th Street NW • Washington DC 20036 • (202) 872-4600 • (800) 227-5558


CASChemPortChemCenterPubs Page