Cytotoxicity of Carbon Nanotubes on J774 Macrophages Is a Purification-Dependent Effect

Figure 2

Raman spectra of CNTs samples. Different Raman spectra obtained from UP-CNTs₁ (a), UP-CNTs₂ (b), P-CNTs₁, (c) and P-CNTs (d). In each figure are shown the D-band at 1338 cm⁻¹ and the G-band at 1600 cm⁻¹ (laser excitation 632.8 nm).

(a)

(b)

(c)

(d)