Table 3 Examples of MWCNTs with their characterization information taken from the published literature

MWNT-7 (lot #05072001 K28)/Mitsui & Co., Inc. (USA)

MWCNT

[5, 46–50]

L (SEM, μm)

3.86

D (SEM, nm)

49 ± 13.4

Trace metal contamination [sodium (0.41 %) and iron (0.32 %)] (Also reported 1.32 % for total and 1.06 % for iron content)

0.78

SSA (BET, m²/g)

26

Zeta potential (mV)

-11

Number of walls

20–50

Baytubes/Bayer Material Science, (Germany; no longer commercially available)

MWCNT

[1, 50]

Cobalt content (%, wt/wt) (ICP-OES)

0.46

Content of cobalt (Co) (%, wt/wt) (AAS)

0.53

Elemental analysis (% carbon-oxygen)

98.6–1.4

SSA (BET, m²/g)

253

Bulk density (g/cm³)

0.16

NM400 and NM402/JRC

NM400

[45, 51, 52]

L (SEM, μm)

0.7–3

D (SEM, nm)

5–35

Impurities total, % Al, % Co

5.38 total, 0.24, 0.58

(Also reported 13 % for total impurities)

Defects

1.2

SSA (BET, m²/g)

245.8

NM401/JRC

CNT_Large

[45, 52]

L (SEM, TEM, μm)

4.05 ± 2.4

D (SEM, TEM, nm)

67 ± 26.2

Impurity (%)

3

SSA (BET, m²/g)

14.6

NM402/JRC

NM402

[45, 51]

L (SEM, μm)

0.7–4

D (SEM, nm)

6–20

Impurities total, % Al, % Co

3.16,

(Also reported 13 % for total impurities)

3.00 x 10^-4, 2.39

Defects

1.12

MWCNTs/Helix Materials Solutions, Inc. (Richardson, TX)

MWCNT

[53–55]

L (TEM, μm)

0.3–50

D (TEM, nm)

10–30

Purity (TGA, %)

>94

Metal content % Ni, %La (ICP-AES)

0.34 and 0.03 by weight

Metal %Ni (EDX)

0.12

SSA (BET, m²/g)

109

Zeta potential (mV)

-13 ± 2