Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1887583 | Radiation Physics and Chemistry | 2007 | 8 Pages |
Abstract
Changes in the intensities of the functional groups within the surface region (upper 500Â nm) of cellulose nitrate films, exposed to 0.5Â MeV protons and processed chemically to visualize proton tracks, have been determined quantitatively by attenuated total reflectance (ATR) infrared spectrometry. Within the penetration depth of protons resulting from the thermal neutron reaction, 14N(n, p)14C at a neutron fluence of 2Ã1011, absorption intensities of nitrate (-ONO2) and ether (-C-O-C-) are depleted by up to 37% and 12% at respective characteristic vibrational frequencies. The observed cleavage of the ether linkages (C-O-C at 1060Â cmâ1) in the main cellulose chain creates lower molecular weight polymer fragments, and also causes depolymerization. Both reactions increase the accessibility of the polymer to chemical attack by the NaOH etchant at the chemically altered sites. The unique track registration of low energy protons (0.5-0.3Â MeV) in cellulose nitrate primarily results from selective chemical induced damage from energy deposition interactions at bonded nitrate group sites.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Radiation
Authors
J.W. Mitchell, A. Addagada,