Gamma irradiation, thermal conductivity, and phase change tests of the cement‐hyperbranched poly amino‐ester‐block‐poly cabrolactone‐polyurathane plaster‐lead oxide and arsenic oxide composite for development of radiation shielding material

In this work, polymer composites of high density polyethylene reinforced by micro-sized and nanosized cadmium oxide, lead oxide, and a mixture of both with filler weight fraction of 30% were prepared by compression molding technique and characterized by scanning electron microscope. This investigation aims to present a comparative study between cadmium oxide and lead oxide according to their sizes as fillers in high density polyethylene polymeric matrix for gamma-radiation shielding applications. The mass and linear attenuation coefficients of the investigated composites were measured as a function of g-ray energies ranging from 59.53 keV to 1408.01 keV using standard radioactive point sources (241Am, 133Ba, 137Cs, 60Co, and 152Eu). The measurements were made with a narrow beam geometry setup using a well calibrated hyper pure germanium cylindrical detector. The theoretical values of the mass attenuation coefficients were evaluated using the XCOM program database. The experimental results demonstrated that, according to the filler size, cadmium oxide composite is better as a gamma absorber in the energy region less than 81 keV, while lead oxide composite is better in the energy region greater than 81 keV. Moreover, for the same chemical structure and weight fraction of the composite, nano fillers show better attenuation performance than micro fillers in high density polyethylene based radiation shielding material.

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Shape-stabilized phase change materials with high thermal conductivity based on paraffin/graphene oxide composite

Energy Conversion and Management ◽

10.1016/j.enconman.2012.11.023 ◽

2013 ◽

Vol 67 ◽

pp. 275-282 ◽

Cited By ~ 210

Author(s):

Mohammad Mehrali ◽

Sara Tahan Latibari ◽

Mehdi Mehrali ◽

Hendrik Simon Cornelis Metselaar ◽

Mahyar Silakhori

Keyword(s):

Thermal Conductivity ◽

Graphene Oxide ◽

Phase Change ◽

Phase Change Materials ◽

High Thermal Conductivity ◽

Oxide Composite

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Preparation and characterization of an expanded perlite/paraffin/graphene oxide composite with enhanced thermal conductivity and leakage-bearing properties

RSC Advances ◽

10.1039/c5ra23176k ◽

2015 ◽

Vol 5 (130) ◽

pp. 107514-107521 ◽

Cited By ~ 10

Author(s):

Zeyu Lu ◽

Dongshuai Hou ◽

Biwan Xu ◽

Zongjin Li

Keyword(s):

Thermal Conductivity ◽

Graphene Oxide ◽

Phase Change ◽

Phase Change Material ◽

Expanded Perlite ◽

Oxide Composite ◽

Change Material ◽

Enhanced Thermal Conductivity

A novel phase change material (PCMs) of expanded perlite/paraffin/graphene oxide (EP/PA/GO) with enhanced thermal conductivity and leakage-bearing properties was fabricated by depositing GO films on the surface of the EP/PA composite.

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Gamma Irradiation and the Radiation Shielding Characteristics: For the Lead Oxide Doped the Crosslinked Polystyrene-b-Polyethyleneglycol Block Copolymers and the Polystyrene-b-Polyethyleneglycol-Boron Nitride Nanocomposites

Polymers ◽

10.3390/polym13193246 ◽

2021 ◽

Vol 13 (19) ◽

pp. 3246

Author(s):

Zehra Merve Cinan ◽

Burcu Erol ◽

Taylan Baskan ◽

Saliha Mutlu ◽

Sevil Savaskan Yilmaz ◽

...

Keyword(s):

Block Copolymers ◽

Boron Nitride ◽

Gamma Irradiation ◽

Gamma Rays ◽

Lead Oxide ◽

Gamma Ray ◽

Mean Free Path ◽

Radiation Shielding ◽

Polymer Mixture ◽

Crosslinked Polystyrene

This work aimed to research the efficiency of gamma irradiation and shielding characteristics on the lead oxide (PbO) doped the crosslinked polystyrene-b-polyethyleneglycol (PS-b-PEG) block copolymers and polystyrene-b-polyethyleneglycol-boron nitride (PS-b-PEG-BN) nanocomposites materials. The crosslinked PS-b-PEG block copolymers and PS-b-PEG-BN nanocomposites mixed with different percentage rates of PbO were used to research gamma-ray shielding characteristics. The synthesis of the copolymer was done by emulsion polymerization methods. The characterization and morphological analyses of irradiated samples were explored handling with the Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR), Gel Permeation Chromatography (GPC), Thermogravimetric Analysis (TGA), and Scanning Electron Microscope (SEM) methods. The gamma-rays that were emitted from the E 152u source were observed with a High Purity Germanium (HPGe) detector system and examined with a GammaVision computer program. Our samples, including the different percentage rates of the PS-b-PEG (1000, 1500, 10,000), BN, and PbO, were irradiated in various gamma-ray photon energy regions (from 121.78 keV to 1408.01 keV). Then, Linear-Mass Attenuation Coefficients (LACs-MACs), Half-Tenth Value Layer (HVL), Mean Free Path (MFP), and Radiation Protection Efficiency (RPE) values of the samples were calculated. Via crosschecking the acquired data from samples with and without PbO and BN, it was observed that, if the different percentage rates by weight nano-powder of PbO and BN are added in the polymer mixture, it can be used as a convenient shielding material against gamma rays.

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Comparison of Lead, Copper and Aluminium as Gamma Radiation Shielding Material through Experimental Measurements and Simulation Using MCNP Version 4c

International Journal of Contemporary Research and Review ◽

10.15520/ijcrr/2018/9/08/584 ◽

2018 ◽

Vol 9 (08) ◽

pp. 20193-20206 ◽

Cited By ~ 1

Author(s):

Md. Akhlak Bin Aziz ◽

Md. Faisal Rahman ◽

Md. Mahidul Haque Prodhan

Keyword(s):

Gamma Radiation ◽

Sodium Iodide ◽

Experimental Approach ◽

Radiation Shielding ◽

Test Material ◽

Simulation Techniques ◽

Radiation Sources ◽

Simulation Monte Carlo ◽

Shielding Material ◽

Code Version

The paper compares Lead, Copper and Aluminium as gamma radiation shielding material using both experimental and simulation techniques. Cs- 137 (662KeV), Na-22 (511KeV) and Na- 22(1274KeV) were used as gamma radiation sources and a sodium iodide (NaI) detector was used to detect the radiation. Variations were noted for detected gamma count rates by changing shielding material thickness. In the experimental approach, thickness was varied by placing sheets of a particular test material one by one. For simulation, Monte Carlo n- Particle (MCNP) code version 4c was used and the geometry of the whole experimental setup was plotted in it. The results were then compared for each test material and it was found that lead is the best shielding material for gamma radiation followed by copper and aluminium.

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SOLID-LIQUID PHASE CHANGE AND THERMAL CONDUCTIVITY OF ERYTHRITOL AS A HEAT STORAGE MATERIAL: A MOLECULAR DYNAMICS STUDY

10.1615/ihtc16.nmt.022420 ◽

2018 ◽

Author(s):

Biao Feng ◽

Zi-Qin Zhu ◽

Yi Zeng ◽

Li-Wu Fan

Keyword(s):

Thermal Conductivity ◽

Molecular Dynamics ◽

Liquid Phase ◽

Phase Change ◽

Heat Storage ◽

Storage Material ◽

Heat Storage Material ◽

Solid Liquid

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On the use of green concrete composite as a nuclear radiation shielding material

Progress in Nuclear Energy ◽

10.1016/j.pnucene.2021.103730 ◽

2021 ◽

Vol 136 ◽

pp. 103730

Author(s):

Sukhpal Singh ◽

Kanwaldeep Singh

Keyword(s):

Radiation Shielding ◽

Nuclear Radiation ◽

Green Concrete ◽

Shielding Material

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Thermophysical Properties of Multifunctional Syntactic Foams Containing Phase Change Microcapsules for Thermal Energy Storage

Polymers ◽

10.3390/polym13111790 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1790

Author(s):

Francesco Galvagnini ◽

Andrea Dorigato ◽

Luca Fambri ◽

Giulia Fredi ◽

Alessandro Pegoretti

Keyword(s):

Thermal Conductivity ◽

Energy Storage ◽

Phase Change ◽

Epoxy Resin ◽

Storage Modulus ◽

Thermal Energy ◽

Thermal Energy Storage ◽

Neat Epoxy ◽

Low Density ◽

Syntactic Foams

Syntactic foams (SFs) combining an epoxy resin and hollow glass microspheres (HGM) feature a unique combination of low density, high mechanical properties, and low thermal conductivity which can be tuned according to specific applications. In this work, the versatility of epoxy/HGM SFs was further expanded by adding a microencapsulated phase change material (PCM) providing thermal energy storage (TES) ability at a phase change temperature of 43 °C. At this aim, fifteen epoxy (HGM/PCM) compositions with a total filler content (HGM + PCM) of up to 40 vol% were prepared and characterized. The experimental results were fitted with statistical models, which resulted in ternary diagrams that visually represented the properties of the ternary systems and simplified trend identification. Dynamic rheological tests showed that the PCM increased the viscosity of the epoxy resin more than HGM due to the smaller average size (20 µm vs. 60 µm) and that the systems containing both HGM and PCM showed lower viscosity than those containing only one filler type, due to the higher packing efficiency of bimodal filler distributions. HGM strongly reduced the gravimetric density and the thermal insulation properties. In fact, the sample with 40 vol% of HGM showed a density of 0.735 g/cm3 (−35% than neat epoxy) and a thermal conductivity of 0.12 W/(m∙K) (−40% than neat epoxy). Moreover, the increase in the PCM content increased the specific phase change enthalpy, which was up to 68 J/g for the sample with 40 vol% of PCM, with a consequent improvement in the thermal management ability that was also evidenced by temperature profiling tests in transient heating and cooling regimes. Finally, dynamical mechanical thermal analysis (DMTA) showed that both fillers decreased the storage modulus but generally increased the storage modulus normalized by density (E′/ρ) up to 2440 MPa/(g/cm3) at 25 °C with 40 vol% of HGM (+48% than neat epoxy). These results confirmed that the main asset of these ternary multifunctional syntactic foams is their versatility, as the composition can be tuned to reach the property set that best matches the application requirements in terms of TES ability, thermal insulation, and low density.

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Testing a Gypsum Composite Based on Raw Gypsum with a Direct Admixture of Paraffin and Polymer to Improve Thermal Properties

Materials ◽

10.3390/ma14123241 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3241

Author(s):

Krzysztof Powała ◽

Andrzej Obraniak ◽

Dariusz Heim

Keyword(s):

Thermal Conductivity ◽

Heat Capacity ◽

Thermal Properties ◽

Phase Change ◽

Large Scale ◽

Building Materials ◽

Residential Buildings ◽

Energy Performance ◽

Polymer Content ◽

Volumetric Heat Capacity

The implemented new legal regulations regarding thermal comfort, the energy performance of residential buildings, and proecological requirements require the design of new building materials, the use of which will improve the thermal efficiency of newly built and renovated buildings. Therefore, many companies producing building materials strive to improve the properties of their products by reducing the weight of the materials, increasing their mechanical properties, and improving their insulating properties. Currently, there are solutions in phase-change materials (PCM) production technology, such as microencapsulation, but its application on a large scale is extremely costly. This paper presents a solution to the abovementioned problem through the creation and testing of a composite, i.e., a new mixture of gypsum, paraffin, and polymer, which can be used in the production of plasterboard. The presented solution uses a material (PCM) which improves the thermal properties of the composite by taking advantage of the phase-change phenomenon. The study analyzes the influence of polymer content in the total mass of a composite in relation to its thermal conductivity, volumetric heat capacity, and diffusivity. Based on the results contained in this article, the best solution appears to be a mixture with 0.1% polymer content. It is definitely visible in the tests which use drying, hardening time, and paraffin absorption. It differs slightly from the best result in the thermal conductivity test, while it is comparable in terms of volumetric heat capacity and differs slightly from the best result in the thermal diffusivity test.

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