Validation of alkaline oxidation as a pre-treatment method for elemental quantification in single-walled carbon nanotubes

Abstract

Certified fractions of Ni, Co and Mo in carbon nanotubes were recovered from a fused borate salt bead and measured with ICP-OES.

The elemental analysis and multi-nuclear NMR study of an alkali molten salt used to digest reference and commercial SWCNT powders

“…Of these materials, SWCNT-1 was previously employed to validate the fusion method with a lithium borate ux. 32 This Canadian standard differs signicantly from SRM2483 (NIST), not just in composition and certied elements but also in the structure and allotrope homogeneity of the carbon powder. 34 In fact, the latter is labelled "soot".…”

“…The instrumental parameters used are listed elsewhere. 32 To calibrate the equipment, single-element solutions (with different concentrations) of Cr, Mn, Fe, Co, Ni and Mo were used. They were all derived from the respective 1000 ppm single-element standards.…”

“…The same hue was seen when a lithium ux was used as the reaction medium and attributed to the presence of Co 2+ species. 32 Upon pouring the melt into the beaker containing the diluted acid, a colorless and transparent solution was obtained. The bar charts in Fig.…”

“…fusion) as a viable approach to digest different types of carbons, hence offering a pre-treatment alternative for the elemental analysis of SWCNTs by ICP-OES. 12 More recently, we validated fusion for SWCNTs 32 and tested it on battery-relevant carbon materials with different types of nanotextures (point, radial and planar). 13 On the whole, acceptable recoveries (usually, 80-90%) have been achieved for a number of transition metals.…”

New Advances in Fast Methods of 2D NMR Experiments

“…More importantly, NMR has the ability to evaluate information about the environment of each atom and their neighbor's nuclei (both through space and through bond), allowing researchers to differentiate the unique magnetic environments of the same nuclei in different positions of a single molecule. Thus, NMR spectroscopy is extensively used for the identification and in the structural elucidation in a wide Nuclear Magnetic Resonance 2 range of applications in gas [2,3], liquid [4][5][6][7][8][9][10][11][12][13][14][15][16], and solid-state samples [17][18][19][20][21][22][23][24][25][26][27][28]. Nowadays, NMR spectroscopy is one of the most important analytical tools that has been used in several fields.…”