engleski

Poymer nanocomposites with improved resistance to ionizing radiation

In the present study, three different nanocomposites of poly(dimethylsiloxane) (PDMS) with 1 wt.% of nanoparticles (NP) of detonation nanodiamond (DND) (PDMS-DNDS), zinc oxide (ZnO) (PDMS-ZnO), and single-walled carbon nanotubes (SWNT) (PDMS-SWNT) were irradiated under vacuum at room temperature with a 2 MeV proton beam with fluences in the 1013 to 1015 cm-2 range. Modification of the structures and properties of the nanocomposite materials were monitored as a function of proton fluence. Specifically, the vibrational dynamics of PDMS-nanocomposites for unirradiated and irradiated samples, were investigated using Raman and Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR-ATR) and compared. The results were also compared with the results obtained for the unirradiated/irradiated pure PDMS polymer. The Raman and FTIR-ATR spectra of the PDMS nanocomposites exhibit an overall reduction in intensity of the characteristic vibrational bands of the irradiated samples. However, an important difference between the irradiated pure PDMS versus PDMS nanocomposites’ Raman and FTIR spectra appeared ; comparable structural degradation of polymer nanocomposites with ZnO, DND and SWNT fillers takes place at least at one or even two orders of magnitude higher fluence than for pure PDMS, indicating the potential use of ZnO-based, DND-based and SWNT-based polymer composites in high radiation environments. The highest resistance to radiation was demonstrated for PDMS-ZnO samples. Since the benefit is realized at a low loading, the cost of the nanocomposite can be kept low and the polymer retains the other beneficial properties that make them attractive.

nanocomposites; PDMS; ionizing radiation; Raman; FTIR

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