Single-wall carbon nanohorn (SWNH), which is a tubular particle with a cone cap, was oxidized in an oxygen flow at various temperatures. N(2) adsorption at 77 K, thermogravimetry (TG), differential thermal analysis (DTA), transmission electron microscopy, and Raman spectroscopy measurements were carried out on the oxidized SWNHs. The specific surface area of the oxidized SWNHs can be controlled by oxidation temperature, giving the maximum value of 1420 m(2)/g. The pore size distribution by the BJH method and the comparison plot of the N(2) adsorption isotherms of SWNH oxidized at different temperatures against that of as-grown SWNH revealed the minimum oxidation temperature for opening internal nanopores. TG-DTA analyses determined the components of as-grown SWNH: amorphous carbon 2.5 wt %, defective carbon at the cone part 15 wt %, tubular carbon 70 wt %, and graphitic carbon 12 wt %. These systematic analyses provided the exact internal nanopore volume of 0.49 mL/g for pure SWNH particles.
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http://dx.doi.org/10.1021/jp0512661 | DOI Listing |
Nanomaterials (Basel)
December 2024
Department of Chemistry, University of Sherbrooke, 2500, Blvd de l'Université, Sherbrooke, QC J1K 2R1, Canada.
This study delves into the distinctive selective property exhibited by a non-conjugated cholesterol-based polymer, poly(CEM--EHA), in sorting semiconducting single-walled carbon nanotubes (s-SWCNTs) within isooctane. Comprised of 11 repeating units of cholesteryloxycarbonyl-2-hydroxy methacrylate (CEM) and 7 repeating units of 2-ethylhexyl acrylate (EHA), this non-conjugated polymer demonstrates robust supramolecular interactions across the sp surface structure of carbon nanotubes and graphene. When coupled with the Double Liquid-Phase Extraction (DLPE) technology, the polymer effectively segregates s-SWCNTs into the isooctane phase (nonpolar) while excluding metallic SWCNTs (m-SWCNTs) in the water phase (polar).
View Article and Find Full Text PDFACS Nano
January 2025
Department of Chemistry and the Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States.
The reaction of aqueous suspensions of single-wall carbon nanotubes (SWCNTs) with UV-excited sodium hypochlorite has previously been reported to be an efficient route for doping nanotubes with oxygen atoms. We have investigated how this reaction system is affected by pH level, dissolved O content, and radical scavengers and traps. Products were characterized with near-IR fluorescence, Raman, and XPS spectroscopy.
View Article and Find Full Text PDFACS Nano
January 2025
South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
Synthetic single-wall carbon nanotubes (SWCNTs) contain various chiralities, which can be sorted by DNA. However, finding DNA sequences for this purpose mainly relies on trial-and-error methods. Predicting the right DNA sequences to sort SWCNTs remains a substantial challenge.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 21045, USA.
Aqueous two-phase extraction (ATPE) is an effective and scalable liquid-phase processing method for purifying single species of single-wall carbon nanotubes (SWCNTs) from multiple species mixtures. Recent metrological developments have led to advances in the speed of identifying solution parameters leading to more efficient ATPE separations with greater fidelities. In this feature article, we review these developments and discuss their vast potential to further advance SWCNT separations science towards the optimization of production scale processes and the full realization of SWCNT-enabled technologies.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Mathematics, University of Gujrat, Gujrat, 50700, Pakistan.
This study is the application of a recurrent neural networks with Bayesian regularization optimizer (RNNs-BRO) to analyze the effect of various physical parameters on fluid velocity, temperature, and mass concentration profiles in the Darcy-Forchheimer flow of propylene glycol mixed with carbon nanotubes model across a stretched cylinder. This model has significant applications in thermal systems such as in heat exchangers, chemical processing, and medical cooling devices. The data-set of the proposed model has been generated with variation of various parameters such as, curvature parameter, inertia coefficient, Hartmann number, porosity parameter, Eckert number, Prandtl number, radiation parameter, activation energy variable, Schmidt number and reaction rate parameter for different scenarios.
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