Laser and carbon

103 Pages·2017·31.28 MB·English

by  Nicolas Souza

Laser and carbon: nanotube synthesis
and aDisnserntateiona ling
zur Erlangung des Grades
des Doktors der Ingenieurwissenschaften
der Naturwissenschaftlich Technischen Fakultät
der Universität des Saarlandes
von
NICOLÁS SOUZA CARMONA
Saarbrücken
2017
Laser and carbon: nanotube synthesis and annealing

Tag des Kolloquiums: 2 8 . 0 7 .2017
Dekan: P rof. Dr. G. Kickelbick
Berichterstatter: Prof. Dr.-Ing. F. Mücklich
Prof. Dr. V. Presser

Vorsitz: Prof. Dr.-Ing. D. Bähre
Akad. Mitarbeiter: Dr.-Ing. F. Auberti n
II Nicolás Souza Carmona
Laser and carbon: nanotube synthesis and annealing
Written in EU standard: British English (BE) and decimal comma (,)
Results and discussion with decimal point (.) for publishing.

Nicolás Souza Carmona III
Laser and carbon: nanotube synthesis and annealing

IV Nicolás Souza Carmona
Laser and carbon: nanotube synthesis and annealing
Nicolás Souza Carmona V
Laser and carbon: nanotube synthesis and annealing
CAbosntratectn ...t.s... ............................................................................................................................VIII
Zusammenfassung .................................................................................................................... IX
Acknowledgements .................................................................................................................... X
Scientific contributions ............................................................................................................ XII
Featured peer-review publications ...................................................................................... XII
Further peer-review collaborations in laser and/or carbon nanotubes .............................. XII
Talks .................................................................................................................................... XIII
Conference posters ............................................................................................................. XIII
Prize ..................................................................................................................................... XIII
1. Carbon nanotubes.............................................................................................................. 1
1.1. History ........................................................................................................................ 2
1.2. Properties ................................................................................................................... 4
Electrical properties ........................................................................................................... 7
Mechanical properties ....................................................................................................... 8
Optical properties .............................................................................................................. 9
Limiting factors ................................................................................................................ 11
1.3. Synthesis .................................................................................................................. 14
Growth ............................................................................................................................. 14
Synthesis techniques ....................................................................................................... 15
Alternative carbon feedstocks ......................................................................................... 20
2. Motivation and goals ....................................................................................................... 22
3. Materials and methods .................................................................................................... 24
3.1. CNT synthesis ........................................................................................................... 24
Oven-laser apparatus: Pulsed laser deposition ............................................................... 24
Experimental run-through ............................................................................................... 27
VI Nicolás Souza Carmona
Laser and carbon: nanotube synthesis and annealing
3.2. Processing ................................................................................................................ 27
3.3. Characterisation ....................................................................................................... 28
4. Results and discussion ..................................................................................................... 30
4.1. In situ tracking of defect healing and purification of single-wall carbon nanotubes
with laser radiation by time-resolved Raman spectroscopy ............................................... 30
4.2. Scaling up single-wall carbon nanotube laser annealing: effect on electrical
resistance and hydrogen adsorption ................................................................................... 43
4.3. Upcycling spent petroleum cracking catalyst (FC3R): pulsed laser deposition of
single-wall carbon nanotubes and silica nanowires ............................................................ 53
5. Conclusion and outlook ................................................................................................... 65
Appendix .................................................................................................................................. 68
Literature ................................................................................................................................. 74
List of figures ............................................................................................................................ 80
List of symbols .......................................................................................................................... 82
List of abbreviations ................................................................................................................. 84
List of units ............................................................................................................................... 85
Lebenslauf ................................................................................................................................ 87

Nicolás Souza Carmona VII
Laser and carbon: nanotube synthesis and annealing
Abstract
Thanks to their predicted and measured properties, carbon nanotubes (CNTs) are becoming
viable and superior alternatives to many of materials science’s established materials. Yet,
although the divide between model and reality has narrowed, insufficient CNT quality and
purity remain major hindrances to the performance of most CNT-based materials.
Furthermore, CNT precursors are overwhelmingly high-purity petrochemical substances,
hampering sustainable and widespread adoption of CNTs.
These two identified challenges were addressed towards synthesis energy and cost efficiency,
sustainability and material performance. To this end, single-wall CNTs (SWCNTs) were
synthesised in a custom-built oven laser apparatus as the object of this study.
Laser annealing was found to quickly and drastically recrystallise defects and remove
impurities as measured by Raman spectroscopy, thermogravimetry, electrical resistance and
hydrogen adsorption measurements. Results could be reproduced at the micro- and
millimetre scale. Composite processing related damage, artificially introduced into SWCNTs,
was almost completely reversed by laser annealing. Quality and purity levels equal to that of
commercial tubes could be achieved through this technique.
A waste product of petroleum refining, fluid catalytic cracking catalyst residue, was
successfully employed as carbon precursor for SWCNT synthesis, as well as silica nanowires,
onion-like carbons and carbon nanodiamonds.
VIII Nicolás Souza Carmona
Laser and carbon: nanotube synthesis and annealing
Zusammenfassung
Aufgrund Ihrer vielfach prognostizierten aber auch bekannten Eigenschaften, werden
Kohlenstoff-Nanoröhrchen (CNTs) zu konkurrenzfähigen und teilweise überlegenen
Alternativen zu vielen in der Materialforschung etablierten Materialien. Obwohl sich die
„Kluft“ zwischen Modellvorstellungen und Realität verkleinert hat, sind die unzureichende
CNT-Qualität und Reinheit noch immer wesentliche Hindernisse für die Performance der
meisten CNT-basierten Materialien. Darüber hinaus sind CNT-Vorgänger überwiegend
hochreine petrochemische Substanzen, die eine Akzeptanz von CNTs erschweren.
Diese Arbeit befasst sich mit den damit verknüpften Herausforderungen nämlich den Zielen
Energie-/Kosteneffizienz, Nachhaltigkeit und Performance. Zu diesem Zweck wurden
einwandige CNTs (SWCNTs) in einem speziellen Ofen, der mit einem Hochleistungslaser
kombiniert wurde, synthetisiert und näher studiert.
Die Laserbehandlung heilt Defekte und entfernt Verunreinigungen schnell und effizient. Dies
wurde durch Raman-Spektroskopie, Thermogravimetrie, elektrische Widerstandsmessung
und schließlich Wasserstoff-Adsorption bestätigt. Die Ergebnisse konnten im Mikro- und
Millimeterbereich reproduziert werden. Herstellungsbedingte Defekte in den SWCNTs
konnten durch Laserglühen fast vollständig beseitigt werden. Durch diese Technik konnten
Qualität und Reinheitsgrade erreicht werden, die denen von handelsüblichen Nanoröhrchen
entsprechen.
Katalysatorrückstände des Cracking Prozesses während der Erdölraffination wurden dabei für
die Synthese von SWCNTs, sowie Silica-Nanodrähten, „Onion-like Carbon“ und Kohlenstoff-
Nanodiamanten eingesetzt.
Nicolás Souza Carmona IX
Laser and carbon: nanotube synthesis and annealing
Acknowledgements
Having explored different approaches at such a vast and arduous undertaking, I naturally
proceeded with structure and order, from broad to specific, trying not to leave anything out.
Half way through, I realised I had no idea what I was doing and impostor syndrome kicked in.
Who cares about this? Why am I doing this? Then, inspiration appeared like a fresh Mensa
Tüte full of edible goodies (not just magazines and ads). The acknowledgements were on their
way.
These emotional salutations are for another enterprise, the seven years preceding; nods to
people who made this project start, live and conclude, chronologically. Structure be damned.
First, I must thank my Schwester, Paula, for having believed in me and convinced me that a
PhD was within my reach. Thanks to her, her personality, professionalism and work ethics, I
benefited – as I often have – from people’s misguided beliefs that intelligence runs in the
family (some school teachers now know better). Her reputation preceded me and she, along
with Dr. Sebastián Suarez, fought to get me in. His presentation on why we should make
carbon nanotubes at FuWe – we have a laser, we have an oven, we have graphite … – was
where it all started. This eventually led to Prof. Frank Mücklich believing these two wonderful
people, and thus believing in me. Special thanks to him for the trust, means, support and
flexibility bestowed on me. Unfortunately, rancid capitalism and the 2008 financial crisis also
set the stage for my contacts and job promises to vanish, nudging me in the right direction.
To my office homies, Federico Lasserre and Dr. Suarez, my mentors, I owe my day-to-day
wellbeing; two-one-one foreva’. You kept me afloat and never eager to call it a Feierabend.
Regular motivational talks and wake-up calls kept me on track. The same goes for the greater
FuWe cosmos: friends, colleagues, foosball fiends, chill-out area and kitchen procrastinators,
parties and get-togethers; the Germans, the Latin Americans, the French, the Asians; my
extended family.
A round of applause for Dr. Flavio Soldera for securing funding for me (thank you DAAD) and
for international projects (thank you European Commission), with which I worked, travelled
and grew as a scientist and as a person.
X Nicolás Souza Carmona