Implantation of amino functionality into amorphous carbon sheet surfaces by NH3 plasma

Amorphous carbon (AC) sheet surfaces were modified with ammonia (NH3) plasma in order to form primary amino groups on AC surfaces. The NH3 plasma modification formed both nitrogen- and oxygen-containing groups on the AC sheet surfaces, and the contact angle of water against the modified AC surfaces decreased from 76° to 64°–56°. The formation of primary amino groups preferred NH3 plasma operated at a low rf power (5–10 W) to that at a high power. The concentration of primary amino groups was strongly influenced by how much rf power the NH3 plasma was operated. The NH3 plasma operated at 10 W was a preferable condition for the formation of primary amino groups on the AC sheet surfaces, and their concentration was 1.3–1.4 N(amino)-atoms/100 C-atoms.