Synchrotron Radiation Effect in the Soft X-ray Region on the Surface Properties of Pyromellitic Dianhydride-Oxydianline Polyimide

Abstract
The surface modification of a polyimide (PI) sheet using synchrotron radiation (SR) was carried out. The PI sheet was irradiated to white radiation ranging between 50–1000 eV in a vacuum chamber. The contact angle of the PI surface with a water droplet was found to decrease from 75° to 58° by the SR irradiation. The variation of chemical components of the PI surface was studied using X-ray photoelectron spectroscopy (XPS). The ratio of peak intensity from the O1s orbital to that from the C1s orbital increased remarkably by SR irradiation. The increase of wettability on the PI surface was ascribable to the production of an O-rich surface by SR irradiation in the soft X-ray region.