Influence of gamma radiation on infrared spectrum of nano SiO2
compound
E.M.Huseynov, A.A.Garibov, R.N.Mehdiyeva
Institute of Radiation Problems of ANAS
AZ 1143, B.Vahabzade 9, Baku, Azerbaijan
elchin55@yahoo.com
SiO2 compound consisting of a 160 m2q-1 special surface area with 20 nm size [1,2] has
been irradiated with Co-60 source at room temperature at 25 kGy, 50 kGy, 75 kGy, 100 kGy and
200 kGy doses respectively. Infrared spectrum of unirradiated and irradiated nano SiO2 samples
at appropriate doses have been shot at “Varian 640 FT-IR” device at 400 – 4000 sm-1 range of
space frequency (wavenumber). In the result of spectrum analysis it has been revealed that due to
the radiation five new peaks appears and two of new obtained peaks (peaks appropriate to 687
and 1640 sm-1 values of space frequency) were formed in the result of gamma radiation influence
on Si – O bond. And other three new peaks (peaks appropriate to 941, 2052 and 2357 sm-1 values
of space frequency) appear as a result of interaction of water with nano SiO2 particles in the
result of radiation. Symmetry type of peaks appropriate to Si-O bonds has been defined and
spatial structure of these types depicted visually.
The main purpose of the analysis of unirradiated sample is to observe new peaks easily
that may arise after radiation. The analogue of experiences conducted in the samples that
exposed to gamma radiation has also been carried out for unirradiated sample at 400 – 400 sm-1
range of wavenumber. If to look through the spectrum obtained before the radiation we can see
that there are four sharp peaks in the sample at 400 – 4000 cm1 range of wavenumber. Three
peaks with 469, 801 and 1089 cm-1 wavenumber existing in the sample are consistent with Si-O
coupling with various modifications. The peak of 3367 cm-1 wavenumber observed in infrared
spectrum is consistent with O-H couplings existing in adsorbed water molecules in nano SiO2
compound. During the irradiation of the sample at relatively high doses (200kGy) the existing
peaks are sharply observed, especially the value of 2052 cm-1 of spatial frequency is seen as a
more convex peak (Fig.).
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Fig. Infrared spectrum of the nano SiO2 compound (after 200kGy)
It has been known from spectra analysis that though there are four peaks in the
unirradiated sample, in the sample irradiated at 200 kGy dose there were nine peaks. So, as a
result of irradiation five new peaks appear and two of the new peaks (the peaks with 687 and
1640 cm-1 values of wavenumber) have been formed purely due to the influence of gamma
irradiation on Si-O bonding. The other three new peaks (the peaks with 941, 2052 and 2357 cm-1
values of wavenumber) are formed in the result of interaction of water in the sample with nano
SiO2 particles within irradiation. Thus, before irradiation there were peaks with 469, 801, 1089
and 3367 cm-1 values of wavenumber, and Si-O asymmetrical angular vibration corresponds to
the value of 469 cm-1, Si-O symmetrical vertical vibration to 801 cm-1, Si-O asymmetrical
vertical vibration to 1089 cm-1 and O-H bonding to 3367 cm-1. From the new peaks with 687,
941, 1640, 2052 and 2357 cm-1 wavenumber appeared after irradiation, symmetrical angular
vibration of Si-O bonding corresponds to the value of 687 cm-1 of wavenumber, Si-OH bonding
to 941 cm-1, radiation defects to 1640 cm-1, Si-H bonding to 2052 cm-1 and CO2 adsorbed from
atmosphere to 2357 cm-1 value.
Reference
1. E.M.Huseynov, A.A.Garibov, R.N.Mehdiyeva “Calculation of the specific surface area of
SiO2 nanopowder and getting nano-SiO2-H2O systems” Azerbaijan Journal of Physics ISSN
1028-8546, Volume XIX, Number 1, p. 10-15, Azerbaijan 2013
2. A.A.Garibov, R.N.Mehdiyeva, E.M. Huseynov, “Synthesis methods of nano SiO2 powder”
Transactions of National Academy of Sciences of Azerbaijan, Series of Physics – Mathematical
and Technical Sciences, Physics and Astronomy, ISSN 0002-3108 Vol. XXXII N5, p 83/152,
Azerbaijan 2012
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