Indian J. Phys. 83 (7), 955-961 (2009) © 2009 IACS Spectroscopic studies of copper and carbon ion irradiated polypropylene Ravinder Singh, Kawaljeet Singh Samra, Ramneek Kumar and Lakhwant Singh* Department of Physics, Guru Nanak Dev University, Amritsar-143 005, Punjab, India E-mail : lakhwant@yahoo.com Abstract : The samples of polypropylene (PP) have been irradiated with 120 MeV 64 Cu 9+ and 70 MeV 12 C 5+ ion beams, with the fluence ranging from 1 × 10 13 to 1 × 10 11 ions/-cm –2 . UV-VIS and FTIR techniques have been used to study the chemical and optical properties of these irradiated polymers. UV spectra revealed that the optical-gap energy decreases by 54 % with copper ion irradiation at the fluence of 1 × 10 13 ions/cm 2 , whereas at the same fluence, carbon beam decreases the optical-gap energy by 20%. FTIR analysis of ion irradiated samples revealed the presence of –OH, C = O and C = C bonds. Alkyne formation has been observed only in the case of copper ion irradiation. Keywords : Polypropylene, optical-gap energy, UV-VIS and FTIR techniques. PACS No. : 71.20.Rv 1. Introduction When a swift heavy ion enters a polymer target, it loses most of its energy in exciting and ionizing the atoms along its trajectory. The high value of energy deposited in a very small cylindrical region around the ion path, called latent track, leads to dramatic modifications in the target material [1-3]. The changes induced are dependent upon the material, parameters of ion beams and the environment of irradiation process. The induced effects are responsible for altering the properties of the material, which can be determined by different analytical techniques. The UV-visible absorption studies of ion-irradiated polymers provide information regarding the variation in optical band gap [4]. The chemical changes caused by ionizing radiations involve the main-chain scission, cross-linking, creation of free radicals and formation of saturated and unsaturated groups with stimulated evolution of gasses [5-7]. * Corresponding Author