Manufacturing Strategy for Multiwalled Carbon Nanotubes as a Biocompatible and Innovative Material

Table 1

Basic properties of MWCNTs.

MWCNT type	MWCNT-150						Testing method
abbreviation name	NT15	NT15+Fe	NT15-30	NT15-26	NT15-22	NT15-13
Graphitization temperature (°C)	3000^b	3000^b	3000^c	2600^c	2200^c	—
Additional treatment	—	Fe2O3^d	—	—	—	—
Diameter (nm)	150						FE-SEM
Length (μm)	7–10						FE-SEM
Iron content (ppm)	34	730	<20	<20	60	13000	ICP-MS
𝑅 value (𝐼d/I)^a	0.3	0.3	0.2	0.5	0.9	1.4	Raman spectroscopy (785 nm)
MWCNT type	MWCNT-80						Testing method
abbreviation name	NT08	NT08+Fe	NT08-30	NT08-26	NT08-22	NT08-13
Graphitization temperature (°C)	3000^b	3000^b	3000^c	2600^c	2200^c	—
Additional treatment	—	Fe2O3^d	—	—	—	—
Diameter (nm)	80						FE-SEM
Length (μm)	7–10						FE-SEM
Iron content (ppm)	1700	2200	<20	<20	360	21000	ICP-MS
𝑅 value (𝐼d/I)^a	n/a						Raman spectroscopy (785 nm)

^aR refers to the intensity of D band over the intensity of G band.
^bMWCNTs were heated at Showa denko.
^cMWCNTs were heated in our laboratory.
^dNT15 and NT08 were added Fe₂O₃  (1000 : 1), mixed, and sonicated in 0.02% triton-X100 solution. Then, they were filtered and dried at 120°C.
n/a = not available.