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.