Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
On the Stability and Abundance of Single Walled Carbon Nanotubes
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.ORCID-id: 0000-0003-1542-6170
Department of Physics, Umeå University, Department of Physics, University of California.
Physics Department, Göteborg University.
Department of Physics, Umeå University.
Visa övriga samt affilieringar
2015 (Engelska)Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, artikel-id 16850Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Many nanotechnological applications, using single-walled carbon nanotubes (SWNTs), are only possible with a uniform product. Thus, direct control over the product during chemical vapor deposition (CVD) growth of SWNT is desirable, and much effort has been made towards the ultimate goal of chirality-controlled growth of SWNTs. We have used density functional theory (DFT) to compute the stability of SWNT fragments of all chiralities in the series representing the targeted products for such applications, which we compare to the chiralities of the actual CVD products from all properly analyzed experiments. From this comparison we find that in 84% of the cases the experimental product represents chiralities among the most stable SWNT fragments (within 0.2 eV) from the computations. Our analysis shows that the diameter of the SWNT product is governed by the well-known relation to size of the catalytic nanoparticles, and the specific chirality is normally determined by the product’s relative stability, suggesting thermodynamic control at the early stage of product formation. Based on our findings, we discuss the effect of other experimental parameters on the chirality of the product. Furthermore, we highlight the possibility to produce any tube chirality in the context of recent published work on seeded-controlled growth.

Ort, förlag, år, upplaga, sidor
2015. Vol. 5, artikel-id 16850
Nationell ämneskategori
Annan fysik
Forskningsämne
Tillämpad fysik
Identifikatorer
URN: urn:nbn:se:ltu:diva-8424DOI: 10.1038/srep16850ISI: 000364945200001PubMedID: 26581125Scopus ID: 2-s2.0-84947723240Lokalt ID: 6ef8fdc5-e0fd-40e1-8ac0-14060031f749OAI: oai:DiVA.org:ltu-8424DiVA, id: diva2:981362
Anmärkning
Validerad; 2015; Nivå 2; 20151119 (danhed)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2019-06-14Bibliografiskt granskad
Ingår i avhandling
1. A Theoretical Study: The Connection between Stability of Single-Walled Carbon Nanotubes and Observed Products
Öppna denna publikation i ny flik eller fönster >>A Theoretical Study: The Connection between Stability of Single-Walled Carbon Nanotubes and Observed Products
2017 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Alternativ titel[sv]
En Teoretisk Studie: Sambandet mellan Stabiliteten for Enkelväggiga Kolnanorör och Observerade Produkter
Abstract [en]

Over the past 20 years’ researchers have tried to utilize the remarkable properties of single-walled carbon nanotubes (SWCNTs) to create new high-tech materials and devices, such as strong light-weight composites, efficient electrical wires and super-fast transistors. But the mass production of these materials and devices are still hampered by the poor uniformity of the produced SWCNTs. These are hollow cylindrical tubes of carbon where the atomic structure of the tube wall consists of just a single atomic layer of carbon atoms arranged in a hexagonal grid. For a SWCNT the orientation of the hexagonal grid making up the tube wall is what determines its properties, this orientation is known as the chirality of a SWCNT. As an example, tubes with certain chiralities will be electrically conductive while others having different chiralities will be semiconducting.

Today’s large scale methods for producing SWCNTs, commonly known as growth of SWCNTs, gives products with a large spread of different chiralities. A mixture of chiralities will give products with a mixture of different properties. This is one of the major problems holding back the use of SWCNTs in future materials and devices. The ultimate goal is to achieve growth where the resulting product is uniform, meaning that all of the SWCNTs have the same chirality, a process termed chirality-specific growth. To achieve chirality-specific growth of SWCNTs requires us to obtain a better fundamental understanding about how they grow, both from an experimental and a theoretical point of view.

This work focuses on theoretical studies of SWCNT properties and how they relate to the growth process, thereby giving us vital new information about how SWCNTs grow and taking us ever closer to achieving the ultimate goal of chirality-specific growth. In this thesis, an introduction to the field is given and the current state of the art experiments focusing on chirality-specific growth of SWCNTs are presented. A brief review of the current theoretical works and computer simulations related to growth of SWCNTs is also presented. The results presented in this thesis are obtained using first principle density functional theory. The first study shows a correlation between the stability of SWCNT-fragments and the observed products from experiments. Calculations confirm that in 84% of the investigated cases the chirality of experimental products matches the chirality of the most stable SWCNT-fragments (within 0.2 eV). Further theoretical calculations also reveal a previously unknown link between the stability of SWCNT-fragments and their length. The calculations show that at specific SWCNT-fragment lengths the most stable chirality changes. Thus, introducing the concept of a switching length for SWCNT stability. How these new results link to the existing understanding of SWCNT growth is discussed at the end of the thesis.

Ort, förlag, år, upplaga, sidor
Luleå: Luleå University of Technology, 2017
Serie
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
Nyckelord
Single-walled carbon nanotubes, density functional theory, catalytic chemical vapor deposition, chirality-specific growth, stability, length, diameter, edge, chirality
Nationell ämneskategori
Den kondenserade materiens fysik Atom- och molekylfysik och optik
Forskningsämne
Tillämpad fysik
Identifikatorer
urn:nbn:se:ltu:diva-62321 (URN)978-91-7583-837-3 (ISBN)978-91-7583-838-0 (ISBN)
Presentation
2017-05-03, E632, Luleå, 10:00 (Engelska)
Opponent
Handledare
Tillgänglig från: 2017-03-09 Skapad: 2017-03-07 Senast uppdaterad: 2017-11-24Bibliografiskt granskad
2. Single-Walled Carbon Nanotubes: A theoretical study of stability, growth and properties
Öppna denna publikation i ny flik eller fönster >>Single-Walled Carbon Nanotubes: A theoretical study of stability, growth and properties
2019 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Alternativ titel[sv]
Enkelväggiga Kolnanorör : En teoretisk studie av stabilitet, tillväxt och egenskaper
Abstract [en]

Since their discovery over 25 years ago, scientists have explored the remarkable properties of single-walled carbon nanotubes (SWCNTs) for use in high-tech materials and devices, such as strong light-weight composites, efficient electrical wires, supercapacitors and high-speed transistors. However, the mass production of such materials and devices is still limited by the capability of producing uniform high-quality SWCNTs. The properties of a SWCNT are determined by the orientation of the hexagonal grid of carbon atoms constituting the tube wall, this is known as the chirality of the SWCNT.

Today's large-scale methods for producing SWCNTs, commonly known as growth, give products with a large spread of different chiralities. A mixture of chiralities give products with a mixture of different properties. This is one of the major obstacles preventing large-scale use of SWCNTs in future materials and devices. The goal is to achieve growth where the resulting product is uniform, meaning that all SWCNTs have the same chirality, a process termed chirality-specific growth. To achieve this requires a deep fundamental understanding of how SWCNTs grow, both from an experimental and a theoretical perspective.

This work focuses on theoretical studies of SWCNTs and their growth mechanisms. With the goal of achieving a deeper understanding of how chirality arises during growth and how to control it. Thus, taking us ever closer to the ultimate goal of achieving chirality-specific growth. In this thesis, an introduction to the field is given and the current research questions are stated. Followed by chapters on carbon nanomaterials, SWCNTs and computational physics. A review of the state-of-the-art experimental and theoretical works relating to chirality specific growth is also given.

The results presented in this thesis are obtained using first principle density functional theory calculations. Results show that the stability of short SWCNT-fragments can be linked to the products observed in experiments. In 84% of the investigate cases, the chirality of experimental products matches the chirality of the most stable SWCNT-fragments (within 0.2 eV). Further studies also reveal a previously unknown link between the stability of SWCNT-fragments and their length. Calculations show that at specific lengths the most stable chirality changes. Thus, introducing the concept of a switching length for SWCNT stabilities.

This newly found property of SWCNTs is used in combination with previously published works to create a state-of-the-art analytical model to investigate growth of SWCNTs any temperature. Results from the model show that the most stable chirality obtained is dependent on the diameter, length of the SWCNT, the growth temperature and the composition of the catalyst. Finally, a detailed study on the ability of catalyst metals to sustain SWCNT growth points to Pt as an interesting candidate to achieve growth of rarely seen chiralities. The new knowledge gained from these results takes us even closer to achieving chirality-specific growth.

Ort, förlag, år, upplaga, sidor
Luleå: Luleå University of Technology, 2019
Serie
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
Nationell ämneskategori
Den kondenserade materiens fysik Atom- och molekylfysik och optik
Forskningsämne
Tillämpad fysik
Identifikatorer
urn:nbn:se:ltu:diva-73708 (URN)978-91-7790-370-3 (ISBN)978-91-7790-371-0 (ISBN)
Disputation
2019-06-13, E231, Luleå, 09:00 (Engelska)
Opponent
Handledare
Tillgänglig från: 2019-04-23 Skapad: 2019-04-18 Senast uppdaterad: 2019-06-14Bibliografiskt granskad

Open Access i DiVA

fulltext(969 kB)134 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 969 kBChecksumma SHA-512
155d2b3a392a8126cf125e5ab21d9dfe22280b2d3ed54c85dfec9b6ef25b8017c82c2b606812e0fcee68b4f0d35704d7336eb04de516a8ba26db18bdda6af124
Typ fulltextMimetyp application/pdf
fulltext(116 kB)32 nedladdningar
Filinformation
Filnamn FULLTEXT02.pdfFilstorlek 116 kBChecksumma SHA-512
9723a8e80eeaeeea9f37e32fbaa5b32f9e43d50c210d204a90aa64e67fcd22f958fc3fe242689d9b3d51403df49603013ce9e61a8aa23a5f62971b3bd0f0401a
Typ fulltextMimetyp application/pdf

Övriga länkar

Förlagets fulltextPubMedScopus

Personposter BETA

Hedman, DanielLarsson, Andreas

Sök vidare i DiVA

Av författaren/redaktören
Hedman, DanielLarsson, Andreas
Av organisationen
Materialvetenskap
I samma tidskrift
Scientific Reports
Annan fysik

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 166 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

doi
pubmed
urn-nbn

Altmetricpoäng

doi
pubmed
urn-nbn
Totalt: 636 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf