Properties that Influence the Specific Surface Areas of Carbon Nanotubes and Nanofibers

Abstract

Commercially available carbon nanotubes and nanofibers were analyzed to examine possible relationships between their Brunauer–Emmett–Teller specific surface areas (SSAs) and their physical and chemical properties. Properties found to influence surface area were number of walls/diameter, impurities, and surface functionalization with hydroxyl and carboxyl groups. Characterization by electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and elemental analysis indicates that SSA can provide insight on carbon nanomaterials properties, which can differ vastly depending on synthesis parameters and post-production treatments. In this study, how different properties may influence surface area is discussed. The materials examined have a wide range of surface areas. The measured surface areas differed from product specifications, to varying degrees, and between similar products. Findings emphasize the multiple factors that influence surface area and mark its utility in carbon nanomaterial characterization, a prerequisite to understanding their potential applications and toxicities. Implications for occupational monitoring are discussed.

The production and application of carbon nanomaterials from high alkali silicate herbaceous biomass

“…The carbon nanotubes channels in Fig. 4(b) are in the range of 9-11 nm which is in agreement with the results derived from the adsorption/desorption nitrogen curves that showed the formation of MWCTs with a multiwalled of 3-10 walls and 6-15 nm diameter 27 .…”

“…Where a surface area of 50, 175 and 500 m 2 .g −1 corresponds to 40-walled (35 nm diameter), 10-walled (15 nm diameter) and 3-walled (6 nm in diameter) MWCNT. Given the surface area reported in this study, it is obvious that the produced CNTs are MWCTs with multiple walls of 3-10 walls and 6-15 nm diameter 27 . It is worth noting that the lower surface area of the CNTs could be due to the presence of amorphous carbon particles, impurities, multilayer polygonal particles and large graphite platelets 28 .…”

A Carbon Nanotube Packed Bed Electrode for Small Molecule Electrosorption: An Electrochemical and Chromatographic Approach for Process Description

“…The agglomerates are between 10 and 500 µm ( Figure S5) and have pore sizes in the macro range. The specific surface area of the particulate material is around 200 m 2 /g, which is low compared to the single-walled CNT, with up to 1000 m 2 /g [47,48]. However, the commercially available SWCNTs are 10 to 100 times more expensive than commercially available MWCNTs; moreover, no technology for a large-scale production of SWCNTs currently exists.…”

The influence of the size of metal particles on the catalytic activity of Ni and Cu-supported catalysts in methanol reforming reaction

“…Nevertheless, the increase in SSA was not so considerable probably due to simultaneous agglomeration of CNTs [18] (Fig. 1) as well as partial blocking of pore entrances by introduced oxygen-containing groups preventing the entry of the adsorbing gas into inner cavity [19]. These groups were also present on the surface of pristine CNTs; therefore, their elimination could also be the reason for a slight increase in SSA in the case of CNTs annealed at 800 °C.…”