Research Paper: Implantation of Helium in Polyethylene and Polystyrene to Improve Wettability of Surfaces

Abstract

Hydrophilicity is one of the essential properties of biocompatible materials to be placed in the body environment. In this research, improvement in hydrophilicity of the surfaces of polyethylene and polystyrene samples with implantation of helium ion was studied. A 10 µA helium ion beam with an energy of 10 keV delivered by the department of physics university of Tehran’s electrostatic accelerator was used. The samples were bombarded with a beam at two angles of 45° and 90° relative to the surface of the sample. No remarkable difference was observed in the hydrophilicity of the samples bombarded with the two mentioned above angles. Implantation was performed with various fluences in the range of . A variation of the fluence revealed that the contact angle may be reduced 14 and 16 degrees for polyethylene and polystyrene samples, respectively. The surface roughness of the samples was measured before and after ion implantation with an atomic force microscope (AFM). The reported roughness for each sample is the average of 30 measurements. It was observed that ion implantation has the opposite impact on the surface roughness of polyethylene and polystyrene. On average, the surface roughness of polyethylene samples decreased 32 nm, in contrast to the polystyrene roughness, which increased 33 nm.

Keywords

• biocompatible materials
• ion implantation in polymer
• contact angle
• beam energy
• ion accumulation per unit area