Modification of Wetting Property of Polycarbonate by Means of Ion Beam Implantation and Storage in Different Gas Environments

Abstract

AbstracrThe wetting property of polymers is very important in different applications such as biomaterials, textiles, aerospace (fluid management and materials processing in microgravity), and thin film adhesion. Therefore, there is a strong interest in the development of a new technology for the modification at will of this property. The use of low energy ion beams allows the modification of the first surface atomic layers. Nitrogen ions of 500 eV/at. were used to bombard the surface of polycarbonate (PC) samples to a fluence of 5×1016 at/cm2. Five different environments (oxygen, nitrogen, argon, dry air and vacuum) were used to store the samples for some hours (1 to 24 hours) after the implantation. Aging studies of the contact angle (advancing and receding) have shown that the environment gas influences the long term value of the contact angle and helps to maintain the stability of the treated surfaces with the passage of time. XPS and ToF-SIMS have been used to study the chemical effects of both N2+ ion irradiation and storage gas surrounding the samples. The results show faster aging in the case of the samples stored in vacuum, a harmful effect of nitrogen gas on the treatment and the formation of new chemical species for all treatments.