scholarly journals Investigation of polymer-based BaO and rGO nanocomposites for application in low energy X ray attenuation

2019 ◽  
Vol 7 (2B) ◽  
Author(s):  
LILIANE Aparecida SILVA ◽  
Adriana Batistab ◽  
Jefferson Nascimentoc ◽  
Clascidia Furtadoc ◽  
Luiz Faria

Polymeric materials can serve as a matrix for the dispersion of nanomaterials with good attenuation features, resulting in lightweight, conformable, flexible, lead-free and easy-to-process materials. Thus, some well-known radiation shielding materials could be used in low proportion as a filler, for the formation of new materials. On the other hand, nanostructured carbon materials, such as graphene oxide (GO) have been reported recently to show enhanced attenuation properties. For the present work, poly(vinylidene fluoride) [PVDF] homopolymers and its fluorinated copolymers were filled with metallic oxides and nanosized reduced graphene oxides (rGO) in order to produce nanocomposites with increased low energy X ray attenuation efficiency. We objective is to investigate the X ray shielding features of multilayered PVDF/rGO and P(VDF-TrFE)/BaO composites. PVDF/rGO overlapped with P(VDF-TrFE)/BaO thin films were sandwiched between two layers of kapton films of different thickness. The linear attenuation coefficients were measured for monochromatic X ray photons with energy of 8.1 keV. The samples were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Ultraviolet–visible (UV-vis) and Fourier-Transform Infrared (FTIR) Spectroscopy. The linear attenuation coefficient of the multilayered sample was evaluated and compared with the linear attenuation of the individual constituents. It was observed an increase in the attenuation coefficient of the overlapping samples. It is demonstrated that thin films of rGO nanocomposite with thickness of only 0.32 mm can attenuate up to 50% of X ray beams with energy of 8.1 keV, justifying further investigation of these nanocomposites as X ray or gamma radiation attenuators

2008 ◽  
Vol 22 (5) ◽  
pp. 419-428 ◽  
Author(s):  
M.-Ali H. Al-Akhras ◽  
K. Aljarrah ◽  
A. Al-Omari ◽  
H. M. Al-Khateeb ◽  
B. A. Albiss ◽  
...  

The design and slicing technique of artificial soft tissue are presented. Artificial soft tissue has optical penetration properties similar to biological tissues. The soft tissues are made of agar dissolved in water as a transparent tissue (control) incorporated with scatter materials such as polystyrene microspheres and absorbers such as artificial dairy substitute, coffee mate (Carnation Co.). The radiation's interaction with 20 and 40 keV X-ray, and visible light (400–800 nm) with different types of tissue phantoms has been investigated. The half value layer (HVL), attenuation coefficient, energy density and penetration depth through the artificial tissues has been calculated. X-ray radiation depth show significant reduction in soft tissue incorporated with polystyrene microspheres. At extremely low energy (E), the half value layer decreases with increasing the energy, while the attenuation coefficient increase. The calculated values of the half value layers are in very good agreement with experimental results. The calculated values of effective linear attenuation coefficient, are found to be µeff(0.22–0.42). Significant reduction in superficial dose with clear image is found with 10 mm soft tissue filter used. These results suggests: possible enhancement in diagnostic imaging and reduction in excess dose to patients; artificial soft tissue can be used as filter substitute.


Author(s):  
M. A. Salawu ◽  
J. A. Gbolahan ◽  
A. B. Alabi

Long term exposure to very high levels of radiations from medical diagnostic centres, industries, nuclear research establishments and nuclear weapon development have resulted in health effects such as cancer and acute radiation syndrome, hence the need for proper radiation shielding. This paper investigated Epoxy-Lead (II) Oxide (PbO) composite as radiation shielding. The composites were prepared by dispersion of microsized PbO particles into polymeric materials using effective melt-mixing method and cast in a 4 cm by 6 cm rectangular aluminium Mold with a thickness of 5 mm and was allowed to set over night at room temperature. The gamma ray attenuation ability of the composites were studied using gamma ray transmission or attenuation coefficient determination for the gamma ray energy. Three gamma ray sources Ba-133, Cs-137 and Co-60 were employed. The density, linear attenuation coefficient, half value layer (HVL), relaxation length and heaviness of the samples were determined. The measured values of linear attenuation coefficient increased with increasing filler concentration in all the samples at all gamma ray energies. It was also noticed that 40 % and 50 % filler samples attenuates more relative to the other samples under study. The maximum linear attenuation attained was found at energy of 662 keV. The composites have been found to possessed medical gamma-ray attenuation characteristics among the sample materials over a certain photon energy range (0.08 MeV–1.332 MeV) and found useful as a biological radiation shielding against gamma rays.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2212
Author(s):  
Worawat Poltabtim ◽  
Ekachai Wimolmala ◽  
Teerasak Markpin ◽  
Narongrit Sombatsompop ◽  
Vichai Rosarpitak ◽  
...  

The potential utilization of wood/polyvinyl chloride (WPVC) composites containing an X-ray protective filler, namely bismuth oxide (Bi2O3) particles, was investigated as novel, safe, and environmentally friendly X-ray shielding materials. The wood and Bi2O3 contents used in this work varied from 20 to 40 parts per hundred parts of PVC by weight (pph) and from 0 to 25, 50, 75, and 100 pph, respectively. The study considered X-ray shielding, mechanical, density, water absorption, and morphological properties. The results showed that the overall X-ray shielding parameters, namely the linear attenuation coefficient (µ), mass attenuation coefficient (µm), and lead equivalent thickness (Pbeq), of the WPVC composites increased with increasing Bi2O3 contents but slightly decreased at higher wood contents (40 pph). Furthermore, comparative Pbeq values between the wood/PVC composites and similar commercial X-ray shielding boards indicated that the recommended Bi2O3 contents for the 20 pph (40 ph) wood/PVC composites were 35, 85, and 40 pph (40, 100, and 45 pph) for the attenuation of 60, 100, and 150-kV X-rays, respectively. In addition, the increased Bi2O3 contents in the WPVC composites enhanced the Izod impact strength, hardness (Shore D), and density, but reduced water absorption. On the other hand, the increased wood contents increased the impact strength, hardness (Shore D), and water absorption but lowered the density of the composites. The overall results suggested that the developed WPVC composites had great potential to be used as effective X-ray shielding materials with Bi2O3 acting as a suitable X-ray protective filler.


Author(s):  
Ayano Shanko, MD, Et. al.

The aim of the research is to estimate the X-ray shielding properties of different glass systems using Monte Carlo Simulation. X-ray glass is also known as radiation shielding glass. Glass provides protection against the absorption of energy radiation. The shielding layer is formed by a high concentration of lead and barium. The mass attenuation coefficient, the effective atomic number and the effective electron density are used to determine the position of gamma-ray photons in matter. Shield characterization in terms of mass attenuation coefficient (μm), transmission fraction (T), effective atomic numbers (Zeff), half-value layer (HVL) and exposure build-up. factor (EBF) of a glass system is estimated by the Monte Carlo Simulation. The random sampling and statistical analysis are computed using the monte carlo simulation. Various external factors are considered as the input parameters. The different composition of the glass will be examined using the Monte Carlo simulation and the shielding capability would be determined for the various samples.


2018 ◽  
Vol 91 (1087) ◽  
pp. 20180139 ◽  
Author(s):  
Mark Worrall ◽  
Sarah Vinnicombe ◽  
David G Sutton

Objective: This work presents a proof of principle for a method of estimating the thickness of an attenuator from a single radiograph using the image, the exposure factors with which it was acquired and a priori knowledge of the characteristics of the X-ray unit and detector used for the exposure. It is intended this could be developed into a clinical tool to assist with paediatric patient dose audit, for which a measurement of patient size is required. Methods: The proof of principle used measured pixel value and effective linear attenuation coefficient to estimate the thickness of a Solid Water attenuator. The kerma at the detector was estimated using a measurement of pixel value on the image and measured detector calibrations. The initial kerma was estimated using a lookup table of measured output values. The effective linear attenuation coefficient was measured for Solid Water at varying kVp. 11 test images of known and varying thicknesses of Solid Water were acquired at 60, 70 and 81 kVp. Estimates of attenuator thickness were made using the model and the results compared to the known thickness. Results: Estimates of attenuator thickness made using the model differed from the known thickness by 3.8 mm (3.2%) on average, with a range of 0.5–10.8 mm (0.5–9%). Conclusion: A proof of principle is presented for a method of estimating the thickness of an attenuator using a single radiograph of the attenuator. The method has been shown to be accurate using a Solid Water attenuator, with a maximum difference between estimated and known attenuator thickness of 10.8 mm (9%). The method shows promise as a clinical tool for estimating abdominal paediatric patient thickness for paediatric patient dose audit, and is only contingent on the type of data routinely collected by Medical Physics departments. Advances in knowledge: A computational model has been created that is capable of accurately estimating the thickness of a uniform attenuator using only the radiographic image, the exposure factors with which it was acquired and a priori knowledge of the characteristics of the X-ray unit and detector used for the exposure.


Author(s):  
Mohammad Asaduzzaman Chowdhury ◽  
Md. Bengir Ahmed Shuvho ◽  
Md Azizul Islam ◽  
Muhammad Borhan Uddin ◽  
Ruhul Amin Khan

Abstract Radiation shielding is an indispensable ingredient in the design of an integrated system to attenuate the effects of radiation during various operations such as space, aircraft, and nuclear plant. Discerning and exploiting the properties of composite materials compatible for radiation shielding in those applications are therefore primary obligation. In this study, we present here the results of control, ilmenite-, and garnet-based composites radiation shielding capabilities. The gamma radiation shielding competency of control, ilmenite-, and garnet-based composite materials has been examined by using linear attenuation coefficient, mass attenuation coefficient (MAC), tenth value layer (TVL), and half value layer (HVL). A comparison among those composite materials has been studied to find out the best one for radiation shielding material. Factors influencing the radiation shielding capabilities such as mechanical properties, thermal properties, density, surface morphology, and Fourier-transform infrared spectroscopy (FTIR) analysis have been studied in comparative investigations. In this work, we show that garnet-based composite material has viable radiation shielding performances as compared to the control and ilmenite-based composites. Garnet-based composite exhibits lower impact energy to withstand against gamma radiation as compared to the other tested shielding materials.


2014 ◽  
Vol 679 ◽  
pp. 39-44 ◽  
Author(s):  
Ali Basheer Azeez ◽  
Kahtan S. Mohammed ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Andrei Victor Sandhu ◽  
Azmi Rahmat ◽  
...  

Lead metal proved to be toxic. Its lethal effect became eminent. Many developed countries have banned lead usage in various applications. Seeking alternative material to replace lead is a crucial goal. As density concerns, tungsten-brass composite is a good candidate for lead replacement. In this study the radiation shielding effects of tungsten-brass composites were evaluated. To attain this goal, four tungsten-brass sets were prepared. The tungsten (W) wt. % in these specimens was ranged from 50 to 80, the balance is brass. The specimens were sintered at 10500C in alumina tube furnace under protective environment. To evaluate the radiation shielding performance of these specimens, two gamma ray sources, 137Cs and 60Co were utilized. The photon energy levels for these sources were of o.662MeV and 1.25MeV respectively. The measurements were performed using gamma spectrometer contains NaI (Tl) detector. The anti-radiation performance of the tungsten-brass was correlated to that of lead under similar conditions. Vickers micro hardness, relative sintered density, micro structural characterisation and linear attenuation coefficient (μ) were carried out. Samples with the highest Weight percentage of W has the highest hardness value while the one with the lowest Weight percentage of W. The linear attenuation coefficients of the specimens were significantly improved by increasing the W wt. % of the specimen. The linear attenuation coefficients of the tested specimens ranged from 0.85±0.010cm-1 to 1.12±0.049cm-1for 60Co and0.73±0.012 cm-1 to 0.97±0.027 cm-1 for 137Cs. This result indicates that W-brass composites are suitable material for lead replacement as a shielding barrier.Keywords: Attenuation coefficient, radiation shielding, lead, tungsten-brass composites, NaI (Tl).


2013 ◽  
Vol 594-595 ◽  
pp. 1015-1019
Author(s):  
Ali Basheer Azeez ◽  
Kahtan S. Mohammed ◽  
Abdullah Mohd Mustafa Al Bakri ◽  
Hana Ihsan Hasan

Samples of concrete incorporate different waste materials such as iron filings, iron balls of used ball bearings and slags from steel industry were assessed for their anti-radiation attenuation coefficient properties. The attenuation measurements were performed using gamma spectrometer of NaI (Tl) detector. The utilized radiation sources comprised Cs137and Co60radioactive elements with photon energies of o.662 MeV for Cs137and two1.17 and 1.33 MeV energy levels for the Co60. Likewise the mean free paths for the tested samples were obtained. The maximum linear attenuation coefficient values of 0.92±1.12×10-3for CS137and 1.12±1.57×10-3for CO60attained, in this study were for concrete incorporate iron filling wastes of 30 wt. %. The iron balls and the steel slags gave much inferior values. The concrete incorporates iron filings provided the best shielding effect. The microstructure, concretefillings composite density, the homogeneity and particulate distribution were examined and evaluated using different metallographic, microscopic and measurement facilities.


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