Scientists have identified chemical pathways to innovative insulating nanomaterials that can lead to large-scale industrial production in a variety of applications, such as spacesuits and military vehicles. Nanomaterials are thousands of times thinner than human hair, stronger than steel, and nonflammable, helping to block radiation to astronauts and strengthen the armor of military vehicles, for example.
Collaborators at the Princeton Plasma Physics Laboratory (PPPL) at the US Department of Energy (DOE) have proposed a step-by-step chemical pathway to precursors for this nanomaterial, known as boron nitride nanotubes (BNNTs). -Scale production.
Breakthrough brings together Plasma physics And quantum chemistry, which is part of the expansion of research at PPPL. “This is a pioneering study that will take the institute in a new direction,” said Igor Kaganovich, a PPPL physicist who is a senior researcher at the BNNT project and co-author of a treatise detailing the results in the journal. increase. Nanotechnology..
Collaborators have identified an important chemical pathway step in the formation of small clusters of molecular nitrogen and boron that can chemically react when the temperature generated by the plasma jet drops, says Peter University St. Petersburg Institute of Technology. Said the lead author, Yuri Barskov. He developed a chemical reaction pathway by performing quantum chemistry simulations with the help of Omesh Dwivedi, a PPPL intern at Drexel University, and Sierra Jubin, a graduate student in Princeton Plasma Physics.
Interdisciplinary teams include Alexander Khrabry, a former PPPL researcher at Lawrence Livermore National Laboratory, who developed the thermodynamic code used in this study, and students to compile the software and set up simulations. Included was the supporting PPPL physicist Stephane Ethier.
The results unraveled the mystery of how the diatomic molecule or the molecular nitrogen with the second strongest chemical bond in the diatomic molecule is decomposed by the reaction with boron to form various boron nitride molecules, Kaganovich said. Says. “We spent a lot of time thinking about how to get a boron nitride compound from a mixture of boron and nitrogen,” he said. “What we found was that small clusters of boron interacted easily with nitrogen molecules, as opposed to much larger boron droplets, so quantum chemists performed detailed quantum chemistry calculations. I had to do it. “
BNNT is produced by tons and has properties similar to carbon nanotubes found in everything from sporting goods and sportswear to dental implants and electrodes. However, creating a BNNT is so difficult that it limits application and availability.
Demonstration Chemical pathway The formation of BNNT precursors may promote the production of BNNT. The process of BNNT synthesis begins when scientists use a 10,000-degree plasma jet to transform boron and nitrogen gases into plasma consisting of free electrons and nuclei or ions embedded in the background gas. This shows how the process evolves.
- The jet evaporates boron, but the molecular nitrogen remains largely intact.
- As the plasma cools, boron condenses into droplets.
- When the temperature drops to a few thousand degrees, the droplets form small clusters.
- An important next step is the formation of a boron-nitrogen chain by the reaction of nitrogen with small clusters of boron molecules.
- The chains grow longer by colliding with each other and fold into precursors of Boron nitride nanotubes..
“During high temperature synthesis, the density of small boron clusters is low,” Barskov said. “This is the main obstacle to large-scale production.”
The findings have opened a new chapter in BNNT nanomaterial synthesis. “After two years of work, we found a way,” said Kaganovich. “When boron condenses, it forms large clusters that do not react with nitrogen, but the process begins with small clusters that react with nitrogen, leaving a proportion of small clusters as the droplets grow,” he said. ..
“The beauty of this work is that there are experts in plasma and fluid mechanics. Quantum chemistry All these processes can be done together in an interdisciplinary group. Next, we need to compare the possible BNNT output from the model with the experiment. That will be the next stage of modeling. ”
Yuri Barsukov et al, Formation of Boron Nitride Nanotube Precursors During High Temperature Synthesis: Kinetic and Thermodynamic Modeling, Nanotechnology (2021). DOI: 10.1088 / 1361-6528 / ac1c20
Princeton Plasma Physics Laboratory
Quote: Https: //phys.org/news/2021-09-pathway-forerunner-rugged-nanotubes-widespread.html for extensive industrial manufacturing (September 16, 2021) acquired on September 16, 2021 The Road to the Pioneer of Rugged Nanotubes That Can Connect
This document is subject to copyright. No part may be reproduced without written permission, except for fair transactions for personal investigation or research purposes. The content is provided for informational purposes only.
https://phys.org/news/2021-09-pathway-forerunner-rugged-nanotubes-widespread.html The road to pioneering robust nanotubes that can lead to a wide range of industrial manufacturing