irradiation on the main molecular bonds can be
observed: the n(C-C) bond of backbone corresponding
to 970 cm1 wavenumber, symmetric PO2
stretch (ns(PO2)), and asymmetric PO2 stretch
(nas(PO2)) bonds, which are destroyed after
15 min respectively 45 min of irradiation, recovering
after 60 min, case in which the absorbance value
returns to the initial value .