A Model for Nucleation and Growth of Single Wall Carbon Nanotubes via the HiPco Process: A Catalyst Concentration Study

Carver, Robert L.; Peng, Haowei; Sadana, Anil K.; Nikolaev, Pasha; Arepalli, Sivaram; Scott, Clayton; Billups, W. E.; Hauge, Robert H.; Smalley, R. E.

doi:10.1166/jnn.2005.180

Cited by 20 publications

(29 citation statements)

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“…[22] HiPco was the first process that allowed the production of gram-scale quantities of SWNTs, and triggered an explosion of studies on various SWNTs. [23] Even today, many research groups utilize the HiPco process to produce starting materials for various CNT applications. [23] Even today, many research groups utilize the HiPco process to produce starting materials for various CNT applications.…”

Section: Gas-phase Growthmentioning

confidence: 99%

“…[23] Even today, many research groups utilize the HiPco process to produce starting materials for various CNT applications. [23] Heating decomposes Fe(CO) 5 into Fe(CO) n , where n = (0-4), produces Fe atoms condensed into clusters. What is more, the HiPco process can be said to be the forebear of the other SWNT production processes, for its remarkable influence on the subsequently developed methodologies of not only for the electrode applications but also for the purely semiconducting SWNT productions.…”

Section: Gas-phase Growthmentioning

confidence: 99%

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Single‐Walled Carbon Nanotubes in Emerging Solar Cells: Synthesis and Electrode Applications

Jeon

Xiang

Shawky

et al. 2018

Advanced Energy Materials

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years, because of growing concerns over the energy security. Among different types of photovoltaics, silicon solar cells give power conversion efficiencies (PCEs) of over 26% with excellent durability. This technology has already reached the market, and the products are readily available. However as recent technologies, such as flexible smartphones and IoT (internet of things), evolve into more versatile and portable electronics, there is a shift of demand from performance-centric technologies to versatility-oriented technologies. In other words, the paradigm is shifting to flexible, wearable, and light-weight electronic devices. Energy-generating devices are also following the same path. This means that the thin-film solar cell technologies, such as organic solar cells (OSCs) [1][2][3] and perovskite solar cells (PSCs), [4,5] are considered to be the wave of the future with their critical attributes of being ultrathin (<1 mm), light-weight, and solution-processable. [6] These emerging thin-film solar cells have the potential to equal or surpass the PCE of silicon solar cells while having major advantages in terms of production cost, enhanced design and a variety of new functionalities. Furthermore, tandem photovoltaics, [7] which are combined solar cells of PSCs, silicon solar cells, [8] or OSCs, [9,10] are another new and promising category for the future photovoltaic technology. Despite different names of solar cell types, the device structure is largely the same. They commonly share the typical configuration of one photoactive layer in the center, two charge selective layers above and below the active layer, and two electrodes at each end-at least one of which has to be transparent so that sunlight can pass through it. While there has been an intense efficiency race within the emerging thin-film solar cell community, less attention has been paid to other features, such as flexibility and stability. These traits can be enhanced by using new electrodes and charge-selective layers. Not only the functionalities but also photovoltaic performance is heavily dependent on the electrode and the charge-selective layers. Many scientists around the world, thus far, have focused on these layers by developing novel materials and modifying conventional materials to push the boundaries of current thin-film photovoltaic technology.Abundant and mechanically resilient carbon allotropes are composed of carbon atoms only, yet manifest different electronic properties depending on their configurations and arrangements. Of the carbon species, carbon nanotubes (CNTs) are promising materials to be incorporated into the thin-film solar cells owing to a wide range of properties ranging from conductors to semiconductors with different bandgaps based Emerging solar cells, namely, organic solar cells and perovskite solar cells, are the thin-film photovoltaics that have light to electricity conversion efficiencies close to that of silicon solar cells while possessing advantages in having additional functionalities, facile-processability, an...

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Section: Gas-phase Growthmentioning

confidence: 99%

Section: Gas-phase Growthmentioning

confidence: 99%

Single‐Walled Carbon Nanotubes in Emerging Solar Cells: Synthesis and Electrode Applications

Jeon

Xiang

Shawky

et al. 2018

Advanced Energy Materials

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“…This study uses a log‐normal distribution, previously found to closely represent AFM distributions of produced SWCNTs . The log‐normal distribution is defined by two parameters, the average

µ

and standard deviation

σ

of ln( L ).…”

Section: Theorymentioning

confidence: 99%

Assessment of length and bundle distribution of dilute single‐walled carbon nanotubes by viscosity measurements

et al. 2014

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Rheological measurements have long been an invaluable technique in studying mechanical and structural properties of polymers. Measurements on dilute, noninteracting polymer solutions allow the determination of macromolecular structural information, such as molecular weight. This analysis has been complicated by molecular polydispersity; thus, average effects are more commonly reported. Here, we demonstrate polydispersity characterization for rod-like polymers like single-walled carbon nanotubes (SWCNTs). By extending the theory of the rheological behavior of rigid rods, we determine the distribution of length and bundle size in suspensions of SWCNTs by a simple rheological method. The method is based on measuring the viscosity of dilute suspended SWCNTs over a shear rate range spanning the Newtonian and shearthinning regimes. We show that a log-normal distribution in length with minimal bundling accurately describes the viscosity measurements. This rapid new method yields the SWCNT length distribution while relying on bulk samples, which are less prone to artifacts.

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“…Due to their cost-effectiveness, the commercial use of CNF has grown exponentially [3,4]. CNT and CNF are elongated structures with a high aspect ratio (up to 1:1000, length/width) produced predominantly by HiPco, chemical vapor deposition, laser ablation or arc discharge by employing a variety of catalytic metal particles [5]. The purity of CNT and CNF depends on the technology used and on the subsequently applied purification procedures.…”

Section: Introductionmentioning

confidence: 99%

Factoring-in agglomeration of carbon nanotubes and nanofibers for better prediction of their toxicity versus asbestos

et al. 2012

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BackgroundCarbon nanotubes (CNT) and carbon nanofibers (CNF) are allotropes of carbon featuring fibrous morphology. The dimensions and high aspect ratio of CNT and CNF have prompted the comparison with naturally occurring asbestos fibers which are known to be extremely pathogenic. While the toxicity and hazardous outcomes elicited by airborne exposure to single-walled CNT or asbestos have been widely reported, very limited data are currently available describing adverse effects of respirable CNF.ResultsHere, we assessed pulmonary inflammation, fibrosis, oxidative stress markers and systemic immune responses to respirable CNF in comparison to single-walled CNT (SWCNT) and asbestos. Pulmonary inflammatory and fibrogenic responses to CNF, SWCNT and asbestos varied depending upon the agglomeration state of the particles/fibers. Foci of granulomatous lesions and collagen deposition were associated with dense particle-like SWCNT agglomerates, while no granuloma formation was found following exposure to fiber-like CNF or asbestos. The average thickness of the alveolar connective tissue - a marker of interstitial fibrosis - was increased 28 days post SWCNT, CNF or asbestos exposure. Exposure to SWCNT, CNF or asbestos resulted in oxidative stress evidenced by accumulations of 4-HNE and carbonylated proteins in the lung tissues. Additionally, local inflammatory and fibrogenic responses were accompanied by modified systemic immunity, as documented by decreased proliferation of splenic T cells ex vivo on day 28 post exposure. The accuracies of assessments of effective surface area for asbestos, SWCNT and CNF (based on geometrical analysis of their agglomeration) versus estimates of mass dose and number of particles were compared as predictors of toxicological outcomes.ConclusionsWe provide evidence that effective surface area along with mass dose rather than specific surface area or particle number are significantly correlated with toxicological responses to carbonaceous fibrous nanoparticles. Therefore, they could be useful dose metrics for risk assessment and management.

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A Model for Nucleation and Growth of Single Wall Carbon Nanotubes via the HiPco Process: A Catalyst Concentration Study

Cited by 20 publications

References 0 publications

Single‐Walled Carbon Nanotubes in Emerging Solar Cells: Synthesis and Electrode Applications

Single‐Walled Carbon Nanotubes in Emerging Solar Cells: Synthesis and Electrode Applications

Assessment of length and bundle distribution of dilute single‐walled carbon nanotubes by viscosity measurements

Factoring-in agglomeration of carbon nanotubes and nanofibers for better prediction of their toxicity versus asbestos

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