Optical behaviour of swift heavy ions irradiated poly(vinyl alcohol) films

High energy Gamma Irradiation processing of PVDF/BaxSr1-xTiO3 Bio-nanocomposite on Optical Properties

“…The absorbance of all nanocomposites increase after irradiation with doses (4.32 kGy) and (4.98 kGy), this could be due to the production of radiation induced defects which lead to the formation of new energy levels. Another, possible cause may be the excitation of nonbonding electrons generated by the presence of structural defects (due to the creation of free radicals or ions) into the conduction band, in addition to their localized states 8 .…”

“…There are number of reports on different systems, where a decrease in energy gap after irradiation was observed 10,11 . It is argued that the decrease in energy gap after irradiation produces defects, such as radicals, cations, anions, etc in the material which increase the disorder and causing the structural deformation in the system 8,9 . Also according to the density of state model, energy gap decreases with increasing the degree of disorder 11 .…”

Gamma irradiation studies of composite thin films of poly vinyl alcohol and coumarin

“…More precisely here, peak shi demonstrates a strong interaction between PVA and C 16 H 14 O 4 , and giving rise to the localization effects. 24 Moreover, the stretching vibrations of C]C bonds in the aromatic ring, and the deformation vibrations of C-H bonds in CH 2 and CH 3 groups (and aromatic CH groups of compound), are also clearly distinguished in the spectrum. 25 More precisely, the observed bands of PVA/ C 16 H 14 O 4 composites are given in Table 1.…”

“…2. The band at 937 cm À1 indicates the presence of chain like structure of PVA, 24 suggesting the regular inter-chain bridging in a layer structure through sequential distribution of OH groups, conferring the H-bonding functionality to planar geometry in the polymer backbone. However, decrease in intensity of this band with increasing concentration of C 16 H 14 O 4 gives a clear indication of change or alteration to such planer structure, causing strong delocalization of p-electrons, and hence leads to impact various physical properties of polymer.…”

“…However, decrease in intensity of this band with increasing concentration of C 16 H 14 O 4 gives a clear indication of change or alteration to such planer structure, causing strong delocalization of p-electrons, and hence leads to impact various physical properties of polymer. 24,25 The important bands of PVA for different vibrational modes are shown in Fig. 2 and are also given in Table 1.…”