Desktop Growth of Carbon‐Nanotube Monoliths with In Situ Optical Imaging

Hart, A. John; Laake, Lucas van; Slocum, Alexander H.

doi:10.1002/smll.200790026

Cited by 13 publications

(23 citation statements)

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“…Alternatively, gas diffusion through the array may be hindered [14] (in our case diffusion from the sides), however this is unlikely to be the reason in our case since the dimensions of the CNT blocks and the relatively large spacings between them are identical, it is only the number of squares that changes. in our experiments for a given growth temperature, it would appear that the poisoning depends predominantly on the total amount of carbon reaching the particle.…”

Section: Terminal Length Dependence On Pattern Sizementioning

confidence: 88%

Effect of catalyst pattern geometry on the growth of vertically aligned carbon nanotube arrays

Jeong

Olofsson

Falk

et al. 2009

Carbon

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Section: Terminal Length Dependence On Pattern Sizementioning

confidence: 88%

Effect of catalyst pattern geometry on the growth of vertically aligned carbon nanotube arrays

Jeong

Olofsson

Falk

et al. 2009

Carbon

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“…A similar rippling pattern can also occur on forests (composed of initially straight nanotubes) that are intentionally subjected to externally applied mechanical compression ex situ [9][10][11]. The interactions between nanotubes have previously been shown to be important for forest morphology [6][7][8][12][13][14][15][16][17][18][19], and will be considered here.…”

Section: Introductionmentioning

confidence: 93%

Origin of periodic rippling during chemical vapor deposition growth of carbon nanotube forests

Vinten

Bond

Marshall

et al. 2011

Carbon

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Origin of periodic rippling during chemical vapor deposition growth of carbon nanotube forestsgrowth conditions, these forests can show a growth instability that gives rise to periodic ripples that are coherent over a forest-sized scale. Previously, we showed that the uniformity and synchronization of the ripples is sufficient for them to behave as diffraction gratings for visible light. Here, we identify the conditions that reproducibly promote the formation of these ripples. We investigate the formation mechanism via ex situ scanning electron microscopy and in situ optical imaging. While the rippling amplitude varies appreciably, the rippling wavelength varies very little and can be estimated from simple mechanical considerations. We provide evidence that the rippling is a consequence of cohesive interactions between nanotubes and the build up of strain, driven by a non-uniform growth rate. The origin of the non-uniform growth rate is explained.Crown

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“…This study used an ambient-pressure cold-wall reactor 28 to minimize thermal transformations of the precursor gases prior to impinging on the substrate-supported-catalyst. Then, CNTs were grown via three experimental modes: (1) using individual precursors (i.e., acetylene, propargyl alcohol, or propiolic acid) as the only carbon source over a range of partial pressures, (2) adding varied amounts of propargyl alcohol to a fixed partial pressure of acetylene (0.01 atm) to evaluate competitive processes, and (3) using maximum alkyne partial pressures for effluent analysis (Table S2; note that maximum partial pressures of liquid precursors were limited by their vapor pressures).…”

Section: A U T H O R Accepted Manuscript Author Accepted Manuscriptmentioning

confidence: 99%

“…26,54 Cold-wall reactors are intended to minimize gas-phase transformations of precursor species and decouple the thermal treatment of the catalyst and the starting material feedstock gases. Nevertheless, the resistively heated substrate necessary to heat the catalyst warms the bulk reactive zone, allowing for both thermal and catalytic transformations 28,54 and resulting in a wide range of species (Figure 6). Several interesting features emerge.…”

Section: A U T H O R Accepted Manuscript Author Accepted Manuscriptmentioning

confidence: 99%

Oxygen-functionalized alkyne precursors in carbon nanotube growth

2021

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Functionalization of carbon nanotubes (CNTs) with heteroatoms enables covalent attachment, opening up a world of potential material structures. However, common functionalization techniques are hazardous and lack precision. Here, we evaluate an in situ functionalization technique using oxygen-containing alkyne precursors. CNTs were successfully derived from propargyl alcohol and propiolic acid, at 67±7 and 19±3 µm min -1 , respectively. While there was no substantial increase in the oxygen content of resultant CNT structures (all less than 1% O), Fourier transform infrared spectroscopy revealed subtle incorporations of carboxyl and hydroxyl functionality. An analysis of reactor effluent showed that both oxygen-containing species shed oxygen groups, where propargyl alcohol yielded a reactive atmosphere high in methylacetylene, and propiolic acid thermally degraded to acetylene and CO2, potentially explaining the enhanced catalyst lifetimes (approximately 75 min). These results support the universality of alkynepromoting chemistries and delineate the limits of stable, oxygen-bearing alkynes to support point-directed functionalization schemes.

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Desktop Growth of Carbon‐Nanotube Monoliths with In Situ Optical Imaging

Cited by 13 publications

References 0 publications

Effect of catalyst pattern geometry on the growth of vertically aligned carbon nanotube arrays

Effect of catalyst pattern geometry on the growth of vertically aligned carbon nanotube arrays

Origin of periodic rippling during chemical vapor deposition growth of carbon nanotube forests

Oxygen-functionalized alkyne precursors in carbon nanotube growth

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