Enhancement of X-ray Shielding Properties of PVDF/BaSO 4 Nanocomposites Filled with Graphene Oxide
- PDF / 1,046,057 Bytes
- 7 Pages / 432 x 648 pts Page_size
- 21 Downloads / 205 Views
MRS Advances © 2018 Materials Research Society DOI: 10.1557/adv.2018.651
Enhancement of X-ray Shielding Properties of PVDF/BaSO4 Nanocomposites Filled with Graphene Oxide Liliane A. Silva1, Adriana M. S. Batista2, Tiago Serodre3, Annibal T. B. Neto3, Clascidia A. Furtado3, Luiz O. Faria3 1
Depto. Engenharia Nuclear – UFMG, Av. Antônio Carlos, 6627, CEP 31270-970, Belo Horizonte, MG, Brazil
2
Depto. Anatomia e Imagem, Faculdade de Medicina – UFMG, Av. Prof. Alfredo Balena, 190, CEP 30130-100, Belo Horizonte, MG, Brazil
3
Centro de Desenvolvimento da Tecnologia Nuclear, Av. Antonio Carlos 6627, CEP 31270-901, Belo Horizonte-MG, Brazil
ABSTRACT
In this work, we report evidences of the improvement of X-ray attenuation efficiency by the addition of a very small amount of Graphene Oxide (GO) in polymer-based nanocomposite. Poly(vinylidene fluoride) (PVDF) homopolymer and barium sulfate (BaSO4) nanoparticles were mixed. PVDF/BaSO4 nanocomposite was found to attenuate 9.14% of a 20 kV X-ray beam. The addition of only 4.0 wt % of GO nanosheets to the nanocomposite improved this XRay attenuation efficiency to 24.56%. The respective linear attenuation coefficients (μ) were 39.9 cm-1 and 54.4 cm-1, respectively. The X-ray attenuation gradually decreases until 6.71% and 17.62%, respectively, for the X-ray beam with higher energy (100 kV). Fourier transform infrared data revealed that, due to the lack of the bending vibration modes of CF2 molecule at 656 cm-1, 688 cm-1, 723 cm-1, 776 cm-1 and 796 cm-1, characteristics of the γ-crystalline phase of PVDF, the nanocomposites casted from solution are mostly in the β-ferroelectric phase of PVDF, besides the γ-paraelectric phase. SEM micrographs were used to evaluate the dispersion state of graphene sheets and the BaSO4 nanoparticles into the polymeric matrix. UV-Vis spectrometry and Differential Scanning Calorimetry (DSC) were also performed in order to complement the structural analysis. The results confirm that the addition of graphene sheets in PVDF polymer-based nanocomposites enhances the X-ray shielding efficiency. The
Downloaded from https://www.cambridge.org/core. Iowa State University Library, on 17 Jan 2019 at 11:50:34, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1557/adv.2018.651
phenomenon is discussed in terms of the reported anomalous negative thermal expansion coefficient of graphene sheets
INTRODUCTION In Interventional Radiology procedures, high radiation doses are deposited in the patient skin, increasing the probability of future skin cancer. Thus, there is a great interest in developing new radiation attenuator composites that shield part of the X-ray incident beam, aiming to minimize the patient skin injuries [1,2]. Carbon Nanotubes (NTCs) have been reported to enhance the X-ray shielding effects, for photons with energy below 17 keV [3]. The mechanisms behind this anomalous behavior cannot be interpreted by the already established X-ray absorption theory. In particular, recen
Data Loading...
