In situ diagnostics for the study of carbon nanotube growth mechanism by oating catalyst chemical vapor deposition for advanced composite applications Anthony Dichiara To cite this version: Anthony Dichiara. In situ diagnostics for the study of carbon nanotube growth mechanism by oating catalyst chemical vapor deposition for advanced composite applications. Other. Ecole Centrale Paris, 2012. English. NNT : 2012ECAP0042. tel-00763604 HAL Id: tel-00763604 https://tel.archives-ouvertes.fr/tel-00763604 Submitted on 10 Jan 2013 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. ! "" # " $ %&'( ")# * $ )%% + , - + . , , - + - , / tel-00763604, version 1 - 10 Jan 2013 + / ' / )01) 2 13,00 / 4- 5 !6 , , # !" *"7 , , # !"* * 8 , , # *) * !$6 , , # !* ! 96"" , , , # ") 7 : ;6 , , # "" )01)*003) In situ diagnostics for the study of carbon nanotube growth mechanism by floating catalyst chemical vapor deposition for advanced composite applications a dissertation presented by Anthony Dichiara for the degree of Doctor of Philosophy in the subject of Engineering and materials science Ecole Centrale Paris Paris, France November 2012 tel-00763604, version 1 - 10 Jan 2013 i tel-00763604, version 1 - 10 Jan 2013 ➞ 2012 - Anthony Dichiara All rights reserved. ii Thesis advisors Author Jinbo Bai, Laurent Zimmer Anthony Dichiara In situ diagnostics for the study of carbon nanotube growth mechanism by floating catalyst chemical vapor deposition for advanced composite applications Abstract In the vast field of nanoscience and nanotechnology, carbon nan- otubes (CNTs) are of particular interest because of their unique structure which provides them outstanding properties. While the number of CNT-based applications as well as the amount of CNTs produced are increasing year by year, it is essential to understand the mechanisms governing the formation of these nanomaterials to control their structure and organization, maximize the yields, reduce the health and environmental risks and improve the performance of the underlying materials and components. Among the listed synthesis techniques, the aerosol-assisted chemical vapor deposition (CVD) process developed in the laboratory MSSMat allows continuous growth tel-00763604, version 1 - 10 Jan 2013 of multi-walled CNTs (MWNTs) on various substrates by the simul- taneous injection of carbon feedstock(s) (xylene and/or acetylene) and catalytic precursor (ferrocene) in a reactor heated up to a temperature ranging between 400 and 1000 ➦C. The aim of this study was to analyse the different stages of the CNT formation from the first precursor injection until the growth iii iv termination. By the mean of a new experimental approach involving several in situ diagnostics coupled with numerical models, we were able to follow the evolution of the different products and reagents during the synthesis under various thermodynamic and chemical conditions. Hence, after investigating the spatial evolution of the droplets formed in the injection, the nanoparticle germination and nucleation in the gas phase has been studied by time resolved laser-induced incandescence (TRL2I) and laser-induced breakdown spectroscopy (LIBS). A relationship between the size of the particles and the CNTs has been highlighted. Moreover, the chemical reactions during the synthesis were analyzed by mass spectrometry (MS) and gas phase chromatography (GPC). Different reaction pathways have thus been identified depending on the carbon source(s) used, while the effect of hydrogen on the CNT growth, either accelerating or inhibiting based on the CVD conditions, was studied. The substrates’ roles tel-00763604, version 1 - 10 Jan 2013 were then examined by comparing the growth and morphology of the CNTs obtained on various surfaces such as quartz plates, carbon fibers or micro-particles of alumina, silicon carbide, titanium carbide and graphene. The catalytic effect of some substrates or mixtures of substrates on the CNT growth has also been highlighted, as well as the importance of the substrate’s surface/volume ratio on the CNT mass yields. Furthermore, the CNT growth kinetics have been v studied and different mechanisms inducing catalyst deactivation and subsequently growth termination were identified. Finally, the different as-synthesized nanostructures originated from the hybridization of CNTs with other materials were used to prepare high-performance multi-functional composites. The electrical, thermal and mechanical properties of these materials have been examined. Keywords: carbon nanotube, floating catalyst chemical vapor depo- sition, in situ diagnostics, CNT hybridization, nanoparticle, nucleation and growth mechanisms, composite materials. Graphical abstract: CNT growth mechanism by floating CVD. tel-00763604, version 1 - 10 Jan 2013 vi tel-00763604, version 1 - 10 Jan 2013 Contents 1 Introduction 1 1.1 Carbonnanotubehistory. 1 1.2 Carbonnanotubestructure. 6 1.3 Carbonnanotubeapplications . 9 1.4 Carbonnanotubesynthesisroutes . 21 1.5 ProgressinCNTgrowthmechanism. 29 1.6 Summary .......................... 45 tel-00763604, version 1 - 10 Jan 2013 2 Experimental procedure 47 2.1 CNTgrowthbyaerosol-assistedCVD . 47 2.2 Ex situ characterizationmethods . 55 2.3 In situ characterizationmethods. 57 2.4 Summary .......................... 74 3 Catalyst nanoparticle nucleation 77 vii viii CONTENTS 3.1 Theveryfirststageofthesynthesis . 78 3.2 Howtocontrolthenanoparticlesize? . 90 3.3 RelationswiththeCNTgrowth . 94 3.4 Summary ..........................100 4 Chemical reactions in the gas phase 101 4.1 Modelisation and in situ investigations . .101 4.2 Influenceofhydrogen . .108 4.3 Influenceofcarbonsource(s) . .111 4.4 CNTgrowthmechanism . .114 4.5 Summary ..........................116 5 Hidden role of the substrate 119 5.1 Theimportantroleofthesubstrate . .119 5.2 SynergisticeffectonCNTgrowth . .127 5.3 Summary ..........................135 6 The CNT growth stage 137 tel-00763604, version 1 - 10 Jan 2013 6.1 Evidence of a base growth mechanism. 137 6.2 A pseudo in situ parametricstudy. .139 6.3 CNTGrowthkinetics. .145 6.4 Lengthening and thickening method . 158 6.5 Summary ..........................169 7 Conclusions 173 CONTENTS ix 7.1 Summary ..........................173 7.2 Discussionandfutureworks . .175 7.3 Lastbutnotleast. .179 References 186 tel-00763604, version 1 - 10 Jan 2013 x CONTENTS tel-00763604, version 1 - 10 Jan 2013 Listing of figures 1.1.1Electronic configuration of a carbon atom . 2 1.1.2 Electron microscopy images of soot and carbon black . 2 1.1.3Schematicofthegraphiticstructure . 3 1.1.4Schematicofthediamondstructure. 4 1.1.5Schematic of different fullerene molecules . 5 1.1.6 Electron microscopy images of carbon nanotubes . 6 1.2.1 Images of SWNT and MWNT . 7 tel-00763604, version 1 - 10 Jan 2013 1.2.2Zigzag,armchairandchiralnanotubes . 8 1.2.3VariousCNTconfigurations . 9 1.3.1SEM images of PVDF/CNTs-GN composites . 10 1.3.2Frequency dependence of AC conductivity . 12 1.3.3Thermal stability of different composites . 14 1.3.4Strain-stress curves of different composites . 16 1.3.5 Schematic of the reinforcement dispersion in composites . 18 xi xii LISTING OF FIGURES 1.3.6 In situ resistance change as function of strain . 20 1.3.7Cyclic loading with resistance response . 21 1.4.1Schematic of the CNT growth by arc discharge . 22 1.4.2Schematic of the CNT growth by laser ablation . 24 1.4.3 Schematic of the CNT growth by flame combustion . 25 1.4.4Schematic of the CNT growth by electrolysis . 26 1.4.5Schematic of the CNT growth in a solar reactor . 27 1.4.6SchematicoftheCNTgrowthbyCVD . 27 1.4.7 Schematic of the CNT growth by floating catalyst CVD. 29 1.5.1 Schematic diagram of the particle-wire-tube mechanism . 30 1.5.2SEM image of a CNT array grown by floating CVD . 33 1.5.3Schematic of the open-ended tip growth model . 35 1.5.4CNT formation from 3 different catalysts . 36 1.5.5TEMimagesofNinanoparticles . 41 1.5.6Step site on the surface of Co particle . 42 1.5.7 In situ observations of catalyst during CNT growth . 44 1.5.8 Schematic of the screw dislocation-like model . 44 tel-00763604, version 1 - 10 Jan 2013 2.1.1Image of the spray injection system . 49 2.1.2Microscopy images of injected droplets . 50 2.1.3 Droplet diameter distribution at 2 cm after the injector . 51 2.1.4Temperature profiles along the reactor . 52 2.1.5 Schematic of the CNT growth by liquid injection CVD. 53 2.1.6Residence time in the isothermal zone . 54 LISTING OF FIGURES xiii 2.2.1 Observations of CNT-multilayers on ➭-Al 2O3 ....... 56 2.3.1 Energy balance in a particle after heating by a laser . 60 2.3.2Schematic of the overall TRLII system. 64 2.3.3 Typical in situ TRLIIsignals . 66 2.3.4Feemissionspectrum . 68 2.3.5EffectoftheincidentangleonLIBS . 70 2.3.6 Typical in situ LIBSsignals . 71 2.3.7Iron/carbon ratio determined by LIBS . 72 2.3.8LIBS intrusive effect on CNT growth . 72 2.3.9TypicalLIBSandLIIspectra . 73 3.1.1Droplet size distributions in the reactor