Fabrication of NIPAM polymer gel dosimeter and characterization using raman spectroscopy

Abstract

Gel dosimeter is a kind of radiation dosimetry medium that has been extensively applied in radiotherapy treatment. In this study, the samples of NIPAM-based polymer gel that possessed a good potential as 3D radiation dosimetry were fabricated. The samples of polymer gel were irradiated up to 18 Gy by using gamma irradiator with 60Co sources at a constant dose rate. Upon irradiation, the chemical changes in polymer gel were measured and evaluated by using a Raman spectrometer. Polymerization refers to an increment in Raman intensity at 815 cm-1, assigned for C-C stretching mode of NIPAM polymer gel, as the dose was increased. Consumptions of the co-monomers refers to a decrement in Raman intensities at 1025 cm-1 and 2353 cm-1 assigned for C=C stretching modes of NIPAM and BIS respectively, as the dose was increased. Result showed that following irradiation, the amount of carbon single bonds increases while the amount of carbon covalent bonds decreases.