Free volume study of 70MeV carbon induced modification in polymers through positron annihilation

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 244; no. 1; pp. 257 - 260
• Main Authors: Kumar, Rajesh, Ali, S.A., Mahur, A.K., Das, D., Naqvi, A.H., Virk, H.S., Prasad, Rajendra
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2006
• Subjects: C5+ ion irradiation; CR-39(DOP) polycarbonate; Free volume hole; Ion beam modification; PN-6 polymer; Positron lifetime; CR-39(DOP) polycarbonate; Ion beam modification; C5+ ion irradiation; Positron lifetime; PN-6 polymer; Free volume hole
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2005.11.135

Free volume properties of polymers have strong correlation with macroscopic properties and can be modified by radiations and ions. Positron annihilation lifetime spectroscopy (PALS) provide direct information about the dimension, content and size distribution of free volume holes in polymers. CR-39 (DOP), a polycarbonate widely used as ion track detector and polyamide Nylon-6, a high performance plastic having a unique combination of superior mechanical, electrical, chemical and thermal properties were irradiated with 70MeV C5+ ion beam to different fluences ranging from 1011 to 3.7×1013ions/cm2. The results of characterization by PALS are reported here. o-Ps lifetime and the average free volume for both the polymers are found to decrease with fluence, indicating the facilitation of cross-linking. The results are interpreted in terms of change in the free volume. Maximum change of 9.7% in average free volume was observed in PN-6 irradiated to 3.7×1013ions/cm2.