These wing-like extensions on carbon nanotubes may push the technology further into the world of practical and applied materials and systems.

'Winged' nanotubes may lead
to new materials

By Elizabeth Quill

Diamonds are the hardest known substance. Carbon nanotubes are the strongest.

As part of her work at Argonne, Susana Trasobares, along with John Carlisle (both MSD), tried to combine the best of both worlds by creating a composite nanostruc-ture. They wanted to grow tiny carbon tubes with tiny diamonds.

But Trasobares didn't get what she expected. Instead, the experiment altered the surface area of the nanotubes, creating wing-like extensions. Even though the result wasn't what the experimenters were looking for, these modified surfaces may push nanotubes further into the world of practical and applied materials and systems. It also provides insight into how to synthesize an emerging class of material called "nanocarbons," which consist of different allo-tropes — the same elements with different structures — of carbon combined at the nanoscale to yield new materials with unique properties.

"We were trying to get a composite, but the nanotubes were becoming modified," Trasobares said. "Who could have guessed?"

The carbon atoms that make up nanotubes and fullerenes are bonded like graphite in sheets that resemble chicken wire. When the sheets are rolled into a ball they make fullerenes — the soccer-ball-shaped carbon molecules, different from both graphite and diamond. If the sheets are rolled into a seamless cylinder, they create carbon nanotubes.

The unique properties of these nanotubes, including their strength, electrical properties and conducting capabilities, make them useful in electronic and mechanical applications. And they are small — only one ten-thousandth the width of a human hair.

Carbon nanotubes have been used for structural reinforcement and in lithium-ion batteries and television screen displays, but Carlisle said they are still in the prototype stage.

Researchers are looking for ways to alter nanotubes' properties. Carlisle said that by growing diamonds and nanotubes together, he and Trasobares may get a composite structure that is better than the sum of the parts.

They stood the nanotubes up on their ends, like fork tines sticking up, and then put them under the plasma reactor. Since the plasma was usually used to grow ultrananocrystalline diamonds, a type of diamond film with nanometer grains, they thought diamonds would grow on the ends of the tubes.

"Well, it didn't work," Carlisle said. "It was an abysmal failure. This is science at its best."

The plasma ate away the ends of the nanotubes. The carbon reacted with the plasma and vaporized.

However, in one of the samples, some of the nanotubes were knocked into a horizontal position — like crop circles in the nanotube sample. After examining the samples with the help of the Electron Microscopy Center, the researchers discovered that the same etching process that destroyed the vertical nanotubes was simply ripping open the smooth side walls of the horizontal nanotubes. Then carbon atoms bonded to create wings.

Carlisle said he considered naming the modifications "prickly nanotubes" or "flying nanotubes," but Trasobares suggested "graphitic wings" to describe these unique structures, and Carlisle agreed.

"The good part when you do research is that many times you find something you weren't expecting," Trasobares said. "You have to ask: What's going on? What are we getting? Why are we getting it? What does it mean?"

For science, it means there is a new process to modify the smooth unreactive surface of the nanotubes, increasing the surface area and the number of reactive points. Most importantly, the study breaks ground for new nanomaterials and nanocom-posites with new properties.

And researchers can speculate on possible applications.

As the number of reactive zones increases, the number of molecular groups that can attach to the nanotubes increases. Functionalization improves. The increase in surface area could also change electron emission properties, which are important for flat-panel displays. More emission sites means a larger current, which means a brighter display.

Wings could also help anchor the nanotube to polymers. The two rarely make a good connection. With this, the doors are opened for chemical sensors, probe tips, fuel cells, particle X-rays, fabrics, nanowires and artificial muscles.

As the research continues, more applications may be developed. But Carlisle said this won't happen overnight. There are still a lot of tests to do and a lot of problems to solve.

"As scientists, we dream about what things might be possible," Carlisle said. "When you look at the process of how real technology develops, you begin to appreciate how really hard it is."

Additional authors of the report, which was featured on the inside cover of Advanced Materials April issue, are Argonne's James Birrell and Dean Miller (both MSD); Chris P. Ewels of the Composite Systems and Materials Department of the Office National d'Etudes et de Recherches Aerospatiales in France; Odile Stephan of Université Paris Sud; and Bingqing Q. Wei, Pawel Keblinski and Pulickel M. Ajayan of Rensselaer Polytechnic Institute.

The National Science Foundation, Rensselaer Polytechnic Institute, and the U.S. Department of Energy's Offices of Science and of Energy Efficiency and Renewable Energy supported the work.

Kearney Road closes for
Nanoscale Center construction

A portion of Kearney Road in the southwest corner of the Argonne-East site has been closed as construction preparations begin for the laboratory's newest facility, the Center for Nanoscale Materials (CNM).

Drivers and joggers are urged to avoid the construction area, which will be fenced through the construction, expected to last through the spring of 2006.

"There will be lots of truck traffic in the area," said Karen Hellman (OPM), who is managing CNM design and construction. "If you don't need to use the Kearney or Rock Road, please stay away from the area."

Most of the construction traffic will come through the Northgate entrance, Hellman said, although concrete trucks will most likely use Westgate.

The Center for Nanoscale Materials is one of five nanoscale science research centers sponsored by the U.S. Department of Energy. It will offer advanced facilities and expertise for nanoscience and nanotechnology research. The CNM's mission includes supporting basic research and developing advanced instrumentation that will help generate new scientific insights and create new materials with novel properties.

Plans call for a two-story, 83,000 square-foot structure adjoining the western edge of the Advanced Photon Source. Inside will be clean-room and specialized research laboratories, offices, and meeting space designed to accommodate users, scientific and technical staff, and administrative support.

The building was designed by M+W Zander, of Chicago, and will be built by Walsh Construction. Construction management will be carried out by the CNM project team and Jacobs Engineering Group. The total cost of the project will be about $72 million, including $36 million from the State of Illinois for construction of the building.

"We will begin operations when the building is completed," said project manager Derrick Mancini (XFD). "Equipment installation will continue through 2007, when the center will be fully operational."

Tamale sale to benefit Hispanic Club

The Argonne Hispanic-Latino Club is holding a tamale sale fundraiser.

Tamales will sell for $10 per dozen; $6 per half-dozen; and $1.25 per tamale. Orders will be taken through July 28; tamales can be picked up Monday, Aug. 2, in Building 212, Conference Room A106, from 11:30 a.m. to 1:30 p.m.

For more information, contact Rosa Foote (ET) at ext. 2-4185, or visit the club's Web site.

Cigna offers relationship counseling

Argonne employees can talk to a Cigna Behavioral Health clinical professional about reconnecting emotionally to their partners.

Employees can speak in complete confidence with a Cigna professional who will listen to their concerns, answer questions and provide help and resources to get a relationship back on the road to well-being.

The resource is available 24 hours a day, seven days a week, either by calling, toll-free, 1-888-371-1125 or visiting the Cigna Behavioral Health Web site.

Ask the Directorate

Q. The "Ask-the-Directorate" response (June 7) to the question regarding a mandatory summer vacation proposal, given the directive to take 10 days of vacation this summer, raises an important issue. It indicates Argonne believes "One of the most valued aspects of vacation is the flexibility to use it as you wish." If this is so, why do we continue to require a mandatory vacation period over the Christmas holiday period? For some people, the end of the year is a valuable vacation period, but for many of us it is merely one opportunity, of several, to take vacation time. Why can't we let employees decide if they want to use this valuable time in the dead of winter?

A. The mandatory vacation period during the Christmas-New Year holidays has been in place for more than 20 years. There were two major reasons for instituting this work shutdown period:

n First, a significant proportion of the lab population was already taking vacation days to tie together their holiday time, and that resulted in some loss of productivity.

n Second, at that time there was a DOE initiative to reduce energy consumption at federal facilities. By shutting down the majority of work during this period, the lab was able to meet the energy reduction goals.

The holiday shutdown has become a regular policy because it has proven to be generally popular with lab employees. The productivity issue is still applicable and energy usage is somewhat reduced during this period. In addition, it is a time when maintenance activities are undertaken which would be much more difficult to accomplish when programmatic and other support employees are present.

Q. The toll-free Argonne travel phone line is an excellent resource for the many laboratory employees who must contact on-site employees, their offices (e.g. to retrieve voice-mail), or their labs while on travel or otherwise off-site. However, the travel line switchboard is only attended during business hours.

Since traveling employees often know the laboratory extension numbers they desire, it would be wonderful if they could just dial directly to that extension from the travel line. As many lab activities are conducted around the clock (for example, 24/7 support of APS User operations, often carried out remotely), this capability would save the laboratory and its employees considerable time and also lighten the switchboard load during business hours.

Curiously, I have been able to reach certain newer extensions directly from the travel line, but most Argonne extensions are unreachable and the switchboard has informed me such a feature "is not supposed to work."

A. The Argonne travelers line connects directly into the laboratory voice mail system, which interfaces with the PBX (private branch exchange). Employees calling in are given the choice of reaching the operator or their own voice mail. Though it is not offered as a choice, they can also dial other five-digit extensions. If those extensions have voice mail boxes assigned to them, they will ring and be answered normally, either by the persons or their voice mails. Attempts to reach extensions without voice mail boxes assigned to them will be unsuccessful, largely due to the age of the equipment. Thus, some numbers can be reached and others cannot.

"Ask the Directorate" gives employees an opportunity to ask senior Argonne management direct questions about the laboratory's operations, policy, strategy, mission, budget and goals. Employees should continue to refer job- or workplace-specific questions to their immediate supervisors.

Employees may submit questions to askthedirectorate@anl.gov or fax them to ext. 2-5274. Only questions that include the name of the questioner and contact information, such as e-mail address, office extension or fax number, will be answered.

A link to the "Ask the Directorate" Web site, which includes an e-mail link for submitting questions, can be found on the Inside Argonne home page at www.inside.anl.gov/.

Shrimp boil planned for Thursdays

Argonne's Guest House will hold a lunchtime shrimp boil every Thursday during August from 11:30 a.m. to 1:30 p.m.

All-you-can-eat, peel-and-eat shrimp is $8.95 per person. Other menu items will be available. A salad bar will be offered for an additional $1.95 with any entrée.

Service Awards

Service Awards for July include:

40 Years

Gary A. Sprau (ASD).

35 Years

Leon J. Chmielewski (PFS), Floyd E. Dunn (NE), Terry J. Menozzi (CIS), Victor Omiecinski Jr. (CIS), Beverly A. Otto (ERA), Boyd W. Veal, Jr. (MSD).

30 Years

Peter M. Baldo (MSD), M. H. Bhattacharyya (BIO), Earl E. Feldman (NE), Harold E. Gaines (BIO), Karen K. Larsen (DIS), James E. Matos (NE), Danilo J. Santini (ES), Loren J. Thompson (MSD).

25 Years

Arthur A. Frigo (CMT), Julie Hlavacik (AOD), Letitia M. Kaatz (DIS), James B. Levenson (EA), David K. Metta (SCD), Lovely B. Pruitt (AOD), Virginia S. Razo (IPD), Frank J. Rotella (BIO), Sharon L. Ryan (DIS), John W. Schneider (IPD), Craig E. Swietlik (DIS).

20 Years

Kenneth J. Allen (ENT), Bruce W. Bastian (FAC), L. M. Boxberger (OSS), Randy C. Criddle (FAC), Donald C. Darrington (NPS), Gary N. Davidoff (IPD), S. Paul Henslee (FAC), Susan E. Pepalis (IPD), James W. Richardson Jr. (IPNS).

15 Years

Philip J. Calahan (NE), Karen M. Cobb (MCS), Marsha K. Dial (PFS), Thomas Gill (NE), Richard D. Hislop (AOD), Michael J. Janik (OCF), Robert R. Kalt (ASD), Kevin R. Klosowski (PFS), Anthony F. Krupa (PHY), Gregory K. Ktistou (PFS), Arnold Lowrey (FAC), Paul E. Malak (PFS), Terry L. Meikle (NPS), Claude Nielsen (NPS), Craig D. Roberts (PHY), Edward F. Russell (AOD), Frank A. Smagacz (PFS).

10 Years

Larry M. Aten (PFS), Timothy Branch (EQO), LaJoyce Bullock (MCS), Nick Contos (EQO), Linda Dickey-McGraw (NE), Robert Gleason (PFS), James Hansen (ER), Carol J. Mertz (CMT), Jon W. Pattelli (OTD), Carol A. Quinn (HR), Kurt S. Ririe (ENT), Albert Ryba (PFS), Jeff R. Shelton (ENT), Jennifer A. Turnage (NT).

5 Years

Vito Berardi (ES), Joseph W. Bester (MCS), Valerie A. Davis (EQO), Bruce W. Huckfeldt (PFS), Gerard E. Klazura (ER), Paul E. Reimer (PHY), Arthur R. Vik (NE).

HR Classes

To enroll, contact a Training Management System representative or visit the Human Resources, Performance Development Web site. Full class descriptions are also online (PDF file).

Call Betty Iwan (HR) at ext. 2-3410 for more information.

Classes in July and August include:

"How to Become a Better Communicator" (HR349) -- Wednesday, July 28, 9 a.m. to 4 p.m., Building 212, Conference Room A157.

"Managing Effective Teams" (HR359) -- Wednesday, Aug. 11, 9 a.m. to 4 p.m., Building 212, Conference Room A157.

"Situational Leadership" (HR360) -- Wednesday, Aug. 25, 9 a.m. to 4:30 p.m., Building 201, Conference Room 190. Register by Wednesday, Aug. 11.