Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Big steps toward control of production of tiny building blocks

This is the PPPL Nanosynthesis team.
CREDIT
Elle Starkman/PPPL Office of Communications
This is the PPPL Nanosynthesis team. CREDIT Elle Starkman/PPPL Office of Communications

Abstract:
Nanoparticles, superstrong and flexible structures such as carbon nanotubes that are measured in billionths of a meter -- a diameter thousands of times thinner than a human hair -- are used in everything from microchips to sporting goods to pharmaceutical products. But large-scale production of high-quality particles faces challenges ranging from improving the selectivity of the synthesis that creates them and the quality of the synthesized material to the development of economical and reliable synthesis processes.

Big steps toward control of production of tiny building blocks

Princeton, NJ | Posted on March 9th, 2018

However, this situation could change as a result of research at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), where scientists have developed the diagnostic tools that are being used to advance an improved and integrated understanding of plasma-based synthesis -- a widely used but poorly understood tool for creating nanostructures. PPPL scientists and collaborators outline, in several published papers, recent research that could help to develop controllable and selective fabrication of nanomaterials with prescribed structures. Such basic research could pave the way toward manufacturing advances in a variety of industries.

Unique observations

The papers report unique observations of the synthesis in carbon plasma generated by an electric arc in situ, or as the process unfolds. Researchers create the plasma arc between two carbon electrodes, producing a hot carbon vapor composed of atomic nuclei and molecules that cool and synthesize -- or condense -- into particles that grow into nanostructures by bunching together.

Direct observation has produced "a big step forward in understanding how carbon nanoparticles grow in plasma generated by arc," said physicist Yevgeny Raitses, head of the Laboratory for Plasma Nanosynthesis at PPPL. "The idea now is to combine experimental results with computer modeling for improved control of the process and to apply what we learn to other types of nanomaterials and nanomaterial synthesis."

Following is a look at three papers that break new ground in unraveling the poorly understood arc synthesis process. Support for this work comes from the DOE Office of Science).

Spotting precursors that become nanotubes. Missing from today's knowledge is a detailed understanding of the precursors of nanotubes that are formed from the vapor during synthesis. This poses a key challenge for predicting the mechanism for nanosynthesis with a carbon plasma arc.
Shedding light on this process are new discoveries at PPPL. Research led by physicist Vladislav Vekselman and reported in the journal Plasma Sources Science and Technology shows that what governs the synthesis of carbon nanotubes in a purely carbon electric arc is molecular precursors that include "dimers" -- molecules formed by two carbon atoms.

This finding opens the door to improved predictive modeling of nanosynthesis in carbon arcs. "This is the first time that a laser-induced diagnostic technique has been applied to this type of synthesis," Vekselman said. "We now know where and how much precursor is formed in carbon arc material."

Supporting these findings are simulations of carbon arc synthesis conducted by PPPL physicist Alexander Khrabry. "Our models are based on the underlying physics of vaporization, condensation and the formation of nanostructures," said physicist Igor Kaganovich, deputy head of the PPPL Theory Department. "We apply this to results of the in situ experiments to develop predictions that can be tested with further experiments."

Such predictive models have begun to make progress. "Having in situ measurements while synthesis takes place is a very valuable aid to understanding and modeling," said Brent Stratton, head of the diagnostics division of PPPL and deputy director of the Plasma Science and Technology (PS&T) Department that houses the nanosynthesis laboratory. "What this project shows is the combined value of experiments and modeling for deepening understanding of plasma arc synthesis."

Detecting nanoparticle growth. To further such understanding, researchers must monitor the production of particles in sizes ranging from nanometers all the way down to the atomic scale. PPPL research has now built and demonstrated a unique table-top laser technique for in situ detection of nanoparticle growth. "This custom-made diagnostic helps piece together the puzzle of plasma arc nanosynthesis," said physicist Alexandros Gerakis of PPPL, who designed the technique and is lead author of its description in the journal Physical Review Applied. "There had previously been no good way to monitor the process."
The novel method, derived from a prediction by Mikhail Shneider of Princeton University, detects particles that flow within and from the electric arc. The technique observes particles some five nanometers in size, and could be used to measure materials created by other forms of nanosynthesis as well. Such in situ measurement of nanoparticles during large-volume synthesis could advance understanding of the mechanisms behind nanoparticle growth.

Why some synthesis goes wrong. Among the most promising types of nanomaterials are single-wall carbon nanotubes that carbon arc discharges can produce on an industrial scale. But a key drawback to this method is the impurity of much of the synthesized nanomaterial, which includes a mix of nanotubes, carbon soot and random carbon particles.
A chief source of these drawbacks is the unstable behavior of carbon arcs, PPPL has found. Such behavior creates two modes of production, which the laboratory calls "synthesis-on," for pure nanotube fabrication, and "synthesis-off," for impure results. "The synthesis in plasma arcs is 20 percent on and 80 percent off," said physicist Shurik Yatom, lead author of the results published in the journal Carbon.

In these experiments, Yatom used a conventional arc synthesis technique and filled one of the two electrodes -- called an "anode" -- with graphite powder and a catalyst and found that the synthesis was erratic, switching between the dominant synthesis-off mode and the far less common synthesis-on mode. Fast-camera images, electric characteristics and emission spectra showed that the arc engaged the contents of the anode directly in the synthesis-on mode, but oscillated around the hollow anode in the synthesis-off mode and was unable to interact with the powdered graphite and catalyst inside.

The team also constructed a probing device to selectively collect the synthesized product between the two modes. Evaluating the synthesized nanomaterials was Rachel Selinsky of Princeton University, who found that the vast majority of nanotubes were collected during the "synthesis-on" mode.

The findings revealed the need for stabilizing the arc so that it constantly engaged the graphite and catalyst for the continuous production of single-wall carbon nanotubes. The paper proposes several pathways going forward, ranging from the use of thinner-walled to solid composite anodes for producing nanotubes in a continuous manner with fewer unwanted byproducts.

Finally, understanding the cause of such impurities is crucial for future research at PPPL and elsewhere. As scientists continue to develop methods of in situ characterization for nanostructures, they must monitor the arc behavior and distinguish between results obtained in the synthesis-on and synthesis-off modes.

###

Going forward, PPPL conducts in situ measurements of plasma nanotubes synthesized from boron nitride, a promising material with aerospace and electronics applications. Collaborating on this work are professors Roberto Car of Princeton University, Predrag Kristic of the State University of New York at Stony Brook, and Bruce Koel of Princeton.

Overseeing PPPL nanosynthesis projects is Phil Efthimion, head of the PS&T Department. Following are coauthors of the papers. Nanoparticle precursors: Vladislav Vekselman, Alexander Khrabry, Igor Kaganovich, Brent Stratton and Yevgeny Raitses of PPPL, and Rachel Selinsky of Princeton University. Detecting nanoparticle growth: Alexandros Gerakis, James Mitrani, Brent Stratton, and Yevgeny Raitses of PPPL, Yao-Wen Yeh and Mikhail Schneider of Princeton University. Synthesis on and synthesis off: Shurik Yatom and Yevgeny Raitses of PPPL, Rachel Selinsky and Bruce Koel of Princeton University.

####

About Princeton Plasma Physics Laboratory
PPPL, on Princeton University's Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas -- ultra-hot, charged gases -- and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy's Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

For more information, please click here

Contacts:
John Greenwald

609-243-2672

Copyright © Princeton Plasma Physics Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

RELATED JOURNAL ARTICLE:

Related News Press

News and information

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Laboratories

A battery’s hopping ions remember where they’ve been: Seen in atomic detail, the seemingly smooth flow of ions through a battery’s electrolyte is surprisingly complicated February 16th, 2024

NRL discovers two-dimensional waveguides February 16th, 2024

Catalytic combo converts CO2 to solid carbon nanofibers: Tandem electrocatalytic-thermocatalytic conversion could help offset emissions of potent greenhouse gas by locking carbon away in a useful material January 12th, 2024

Three-pronged approach discerns qualities of quantum spin liquids November 17th, 2023

Govt.-Legislation/Regulation/Funding/Policy

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024

Possible Futures

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Nanotubes/Buckyballs/Fullerenes/Nanorods/Nanostrings

Catalytic combo converts CO2 to solid carbon nanofibers: Tandem electrocatalytic-thermocatalytic conversion could help offset emissions of potent greenhouse gas by locking carbon away in a useful material January 12th, 2024

TU Delft researchers discover new ultra strong material for microchip sensors: A material that doesn't just rival the strength of diamonds and graphene, but boasts a yield strength 10 times greater than Kevlar, renowned for its use in bulletproof vests November 3rd, 2023

Tests find no free-standing nanotubes released from tire tread wear September 8th, 2023

Detection of bacteria and viruses with fluorescent nanotubes July 21st, 2023

Discoveries

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

High-tech 'paint' could spare patients repeated surgeries March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Materials/Metamaterials/Magnetoresistance

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Focused ion beam technology: A single tool for a wide range of applications January 12th, 2024

Catalytic combo converts CO2 to solid carbon nanofibers: Tandem electrocatalytic-thermocatalytic conversion could help offset emissions of potent greenhouse gas by locking carbon away in a useful material January 12th, 2024

Announcements

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Aerospace/Space

Under pressure - space exploration in our time: Advancing space exploration through diverse collaborations and ethical policies February 16th, 2024

Bridging light and electrons January 12th, 2024

New tools will help study quantum chemistry aboard the International Space Station: Rochester Professor Nicholas Bigelow helped develop experiments conducted at NASA’s Cold Atom Lab to probe the fundamental nature of the world around us November 17th, 2023

Manufacturing advances bring material back in vogue January 20th, 2023

Industrial

Boron nitride nanotube fibers get real: Rice lab creates first heat-tolerant, stable fibers from wet-spinning process June 24th, 2022

Nanotubes: a promising solution for advanced rubber cables with 60% less conductive filler June 1st, 2022

Protective equipment with graphene nanotubes meets the strictest ESD safety standards March 25th, 2022

OCSiAl receives the green light for Luxembourg graphene nanotube facility project to power the next generation of electric vehicles in Europe March 4th, 2022

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project