Photoluminescence and optical properties of He ion bombarded ultra-high molecular weight polyethylene

• Published in: Applied surface science 2009-02, Vol.255 (9), p.5016-5020
• Main Author: Abdul-Kader, A.M.
• Format: Article
• Language: English
• Subjects: Activation energy; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Ion beam bombardment; Optical energy gap; Photoluminescence; Physics; Ultra-high molecular weight polyethylene
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2008.12.057

Ion bombardment is a suitable tool to improve the physical and chemical properties of polymer surface. In this study UHMWPE samples were bombarded with 130 keV He ions to the fluences ranging from 1 × 10 12 to 1 × 10 16 cm −2. The untreated and ion beam modified samples were investigated by photoluminescence, and ultraviolet-visible (UV–vis) spectroscopy. Remarkable decrease in integrated luminescence intensity with increasing ion fluences was observed. The reduction in PL intensity with increase of ion fluence might be attributed to degradation of polymer surface and formation of defects. The effect of ion fluence on the optical properties of the bombarded surfaces was characterized. The values of the optical band gap E g, and activation energy E a were determined from the optical absorption. The width of the tail of the localized states in the band gap (E a) was evaluated using the Urbach edge method. With increasing ion fluences a decrease in both the energy gap and the activation energy were observed. Increase in the numbers of carbon atoms ( N) in a formed cluster with increasing the He ion fluence was observed.