Featured Research

from universities, journals, and other organizations

Adaptable Nanotubes Make Way For Custom-Built Structures, Wires

Date:
March 19, 2002
Source:
Purdue University
Summary:
Tiny self-assembled tubes, about 1/1,000th the width of a grain of sand, may now be used as a scaffold to custom-build molecular wires and other components for use in nanometer-sized electronic devices, including some that could be inserted into the body.

WEST LAFAYETTE, Ind. — Tiny self-assembled tubes, about 1/1,000th the width of a grain of sand, may now be used as a scaffold to custom-build molecular wires and other components for use in nanometer-sized electronic devices, including some that could be inserted into the body.

Purdue University researcher Hicham Fenniri has developed a method to create self-assembling nanotubes that can be easily manipulated with specific dimensions or chemical properties.

Like molecular-sized Tinkertoys, the nanotubes can be used as a frame on which various objects — in this case chemicals, molecules or even metals — can be added to give the structure a specific property or direct it toward a selected target, Fenniri says. Tailoring structures in such ways will allow scientists to develop high performance materials or new tools to diagnose and treat disease.

"By using different chemicals on the outside of the structure, you can modify its function or make it bind to a specific target, such as an amino acid," he says. "It's like we have a skeleton, and we just have to put a dress on it. And we can decorate the tube with all sorts of dresses."

The structures developed using Fenniri's self-assembling system may prove to be especially useful in industrial applications because they remain stable under high temperature conditions. In fact, the tiny structures, fueled by hydrophobic attractions between the molecules, actually increase in size under high temperatures, Fenniri says.

"This opposes common wisdom, because generally when you heat something it falls apart," he says. "Our demonstrations show that these structures become more stable under the influence of temperature and attain a new level of self-organization."

The findings — currently on the Proceedings of the National Academy of Sciences' Web site and soon to be published in a print issue of the journal — may pave the way for designing new materials, electronic devices and drug delivery systems for use in the atom-size realm of nanotechnology. Purdue has applied for a patent on the process.

The idea of using very small components, or nanotechnology, to make computers and electrical devices — including biomedical devices that could be inserted into the body — has been the subject of much scientific interest and research. Nanotechnology refers to components only a few nanometers in size. A nanometer is one-billionth of a meter.

To develop the structures, Fenniri and his group expanded on a system they developed last year to produce self-assembling nanotubes. Self-assembly is a principle familiar in biology, where the right mix of biological molecules will interact on their own to form distinctive structures, such as cells, tissues and organs.

"The advantage of using a self-assembly process is that it dramatically simplifies the development process," Fenniri says. "The tubes form naturally and spontaneously. The process also is self-correcting, so the resulting structures are predictable and error-free."

Fenniri and his group created a series of molecules that are "programmed" to link in groups of six to form tiny rosette-shaped rings. The rings are maintained by hydrogen bonds.

The molecules that make up the rings are bipolar, with one end of the molecule working to attract water and the other end repelling it. As the molecules join to form a ring, the water-loving ends connect on the outside of the ring, burying the hydrophobic ends — those with an aversion to water — on the inside.

Fenniri says the molecule's attempts to make order out of these contradictory conditions help spark the self-assembly process, allowing the molecules to form tubes without intervention.

"The inside surface of the ring is trying to avoid water, but the outside surface of the ring is attracting water," he says. "In response to this situation, the assembly links to another ring to protect the inside molecules.

This self-assembly process takes place in water and, although driven by hydrophobic interactions, it is in fact orchestrated by hydrogen bonds, Fenniri says.

As the rings stack to form a tube, electrical charges on the outside of the tube create an electrostatic "belt" that wraps around the structure. Fenniri says the electrostatic belt serves to hold the nanotube together and keep it stable, and provides an anchor to which chemicals or other molecules can be added to the structure.

"This belt, produced from electrostatic bonds, creates a new level of organization that can be manipulated to change the chemical properties of the molecule," Fenniri says.

For example, by attaching a photoactive substance — one that can absorb solar energy and transfer it to another chemical — scientists can create a tube that is capable of absorbing energy from one end and delivering it at the other.

Because the tiny structures flourish in the heat, the custom-built nanotubes may be especially useful in developing applications such as molecular electronics and photonics wires, or biomedical devices that could be inserted into the body, Fenniri says.

The research at Purdue was funded by the National Science Foundation, the American Cancer Society, the American Chemical Society, the Showalter Foundation and Purdue University.


Story Source:

The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length.


Cite This Page:

Purdue University. "Adaptable Nanotubes Make Way For Custom-Built Structures, Wires." ScienceDaily. ScienceDaily, 19 March 2002. <www.sciencedaily.com/releases/2002/03/020312073554.htm>.
Purdue University. (2002, March 19). Adaptable Nanotubes Make Way For Custom-Built Structures, Wires. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2002/03/020312073554.htm
Purdue University. "Adaptable Nanotubes Make Way For Custom-Built Structures, Wires." ScienceDaily. www.sciencedaily.com/releases/2002/03/020312073554.htm (accessed July 24, 2014).

Share This




More Matter & Energy News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com
Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Car Market on the Rebound?

Europe's Car Market on the Rebound?

Reuters - Business Video Online (July 23, 2014) Daimler kicks off a round of second-quarter earnings results from Europe's top carmakers with a healthy set of numbers - prompting hopes that stronger sales in Europe will counter weakness in emerging markets. Hayley Platt reports. Video provided by Reuters
Powered by NewsLook.com
9/11 Commission Members Warn of Terror "fatigue" Among American Public

9/11 Commission Members Warn of Terror "fatigue" Among American Public

Reuters - US Online Video (July 22, 2014) Ten years after releasing its initial report, members of the 9/11 Commission warn of the "waning sense of urgency" in combating terrorists attacks. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins