Hybrid plasma surface modification and ion implantation of biopolymers

In conventional plasma immersion ion implantation (PIII), the sample is immersed in an externally sustained plasma. Negative high voltage pulses are applied to the sample stage to establish an ion sheath around the sample in order to implant ions into the materials. The polymer surface properties can be simply varied by changing the duty cycle between pulse on (ion implantation) and pulse off (plasma exposure) periods during PIII treatment. A high ratio between ion implantation and plasma exposure time can be achieved by increasing the pulsing frequency and elongating the pulse duration. The bioactivity of two polymers surface, polycarbonate and polytetrafluoroethylene (PTFE) is investigated where PIII ion implantation is the dominating effect. Two different polymers are treated by two different ions, e.g., argon and oxygen in two different laboratories demonstrating that the concept of long pulse, high frequency PIII can be converted to different polymers and different experimental systems. It showed that the implanted polycarbonate area did not turn dark blue after applying tetramethyl benzidine (TMB) showing that the horseradish peroxidase HRP was either lost or inactivated. However, after long pulse (200 µs) and high frequency (500 Hz) Oxygen PIII treatment, PTFE surfaces enhanced bacteria and cell attachment.