Evidence of Carboxyl Modification of Hydrogen-Free Diamond-Like Carbon Films Assisted by Radio Frequency Plasma in Vacuum

Figure 3

FT-IR spectra (4000cm⁻¹∼400cm⁻¹) for (S4) the AA-modified DLC film with RF power of 20 W for 1 h, (S5) the AA-modified DLC film with RF power of 20 W for 10 min, and (S2) the hydrogen-terminated DLC film. The insert is FT-IR spectra from 2000 cm⁻¹ to 1200 cm⁻¹. The absorption bands in the region of 1760cm⁻¹∼1700cm⁻¹ are attributed to the C=O bonds in carboxyl groups and those in the region of 2000cm⁻¹∼1780cm⁻¹ to the combination.