A facile route to bulk high-Z polymer composites for gamma ray scintillation.
Ontology highlight
ABSTRACT:
SUBMITTER: Zhao YS
PROVIDER: S-EPMC4271812 | biostudies-literature | 2008 Dec
REPOSITORIES: biostudies-literature
Publications
A facile route to bulk high-Z polymer composites for gamma ray scintillation.
Zhao Yong Sheng YS Yu Zhibin Z Douraghy Ali A Chatziioannou Arion F AF Mo Yueqi Y Pei Qibing Q
Chemical communications (Cambridge, England) 20081014 45
Two classes of bulk high-Z polymer composites were prepared, which exhibit scintillation properties for gamma-radiation detection. ...[more]
Similar Datasets
Project description:Bulk polymer-derived ceramic (PDC) composites of SiCO with an embedded graphene network were produced using graphene-coated poly(vinyl alcohol) (PVA) foams as templates. The pyrolysis of green bodies containing cross-linked polysiloxane, PVA foams, and graphene oxide (GO) resulted in the decomposition of PVA foams, compression of GO layers, and formation of graphitic domains adjacent to GO within the SiCO composite, leading to SiCO composites with an embedded graphene network. The SiCO/GO composite, with about 1.5% GO in the ceramic matrix, offered an increase in the electrical conductivity by more than 4 orders of magnitude compared to that of pure SiCO ceramics. Additionally, the unique graphene network in the SiCO demonstrated a drop in the observed thermal conductivity of the composite (∼0.8 W m-1 K-1). Young's modulus of the as-fabricated SiCO/GO composites was found to be around 210 MPa, which is notably higher than the reported values for similar composites fabricated from only ceramic precursors and PVA foams. The present approach demonstrates a facile and cost-effective method of producing bulk PDC composites with high electrical conductivity, good thermal stability, and low thermal conductivity.
| S-EPMC6641334 | biostudies-literature
Project description:X-ray imaging technology is critical to numerous different walks of daily life, ranging from medical radiography and security screening all the way to high-energy physics. Although several organic chromophores are fabricated and tested as X-ray imaging scintillators, they generally show poor scintillation performance due to their weak X-ray absorption cross-section and inefficient exciton utilization efficiency. Here, a singlet fission-based high-performance organic X-ray imaging scintillator with near unity exciton utilization efficiency is presented. Interestingly, it is found that the X-ray sensitivity and imaging resolution of the singlet fission-based scintillator are dramatically improved by an efficient energy transfer from a thermally activated delayed fluorescence (TADF) sensitizer, in which both singlet and triplet excitons can be efficiently harnessed. The fabricated singlet fission-based scintillator exhibits a high X-ray imaging resolution of 27.5 line pairs per millimeter (lp mm-1 ), which exceeds that of most commercial scintillators, demonstrating its high potential use in medical radiography and security inspection.
| S-EPMC10323610 | biostudies-literature
Project description:Low-energy X-rays have a predominant role in medical diagnostic applications, grown tremendously during recent Covid-19 pandemic times. Synthesis of stable, PMMA/polystyrene-BiI3 composites has been done through a facile, low-cost, dry-tumble mixing technique for direct X-ray detector applications. Comparative analysis of structural, optical, and photocurrent responses upon irradiation with low-energy X-rays (30 and 60 kV) ensue that PS-BiI3 demonstrates high SNR 3300, sensitivity 189 µC Gy-1 cm-3 and fast response time 30 ms, at dose rate 1.68 mGy s-1, affirming the composite to be prospective candidate for low-energy, room-temperature, direct X-ray detectors under low bias conditions.Graphical abstractSupplementary informationThe online version contains supplementary material available at 10.1557/s43579-022-00185-6.
| S-EPMC9030686 | biostudies-literature
Project description:The polymer matrix with introduced carbon-based nanofiber displays fascinating properties. They have inspired extensive research on the synthesis of polymer composites, which have been applied in catalysis, electronics, and energy storage. In this report, we reported a facile and efficient method to prepare poly(p-phenylene benzobisoxazole) (PBO)/nanographene (PNG) composites fibers via in-situ polymerization, accompanied by the reduction from (nanographene oxide) NGO to (nanographene) NG. By tuning the ratio of feeding PBO monomer to NGO, various composites fibers with 0.1⁻1 wt % contents of NG were obtained. The efficient PBO chains grafting made NG uniformly disperse in the PBO matrix, and it also increased the uniformity of the packing orientation of PBO chains. Consequently, the tensile strength, tensile modulus, and thermal stability of the obtained PNG composites fibers had been improved significantly. In addition, the composites fibers with 0.5 wt % NG exhibited a 25% increment in tensile strength, and a 41% enhancement in tensile modulus compared with neat PBO fibers. It reveals an excellent reinforcement to PBO composites fibers with NG.
| S-EPMC6432332 | biostudies-literature
Project description:Two-dimensional (2D) tungsten diselenide (WSe2) has attracted considerable attention in the field of photovoltaic devices owing to its excellent structure and photoelectric properties, such as ordered 2D network structure, high electrical conductivity, and high mobility. For this test, we firstly prepared different sizes (NS1-NS3) of WSe2 nanosheets (NSs) through the ultrasonication method and characterized their structures using the field emission scanning electron microscope (FE-SEM), Raman spectroscopy, and X-ray powder diffraction. Moreover, we investigated the photovoltaic performance of polymer solar cells based on 5,7-Bis(2-ethylhexyl)benzo[1,2-c:4,5-c']dithiophene-4,8-dione(PBDB-T):(6,6)-phenyl-C71 butyric acid methyl ester (PCBM) with different WSe2 NSs as the active layer. The fabricated PBDB-T:PCBM active layer with the addition of NS2 WSe2 NSs (1.5 wt%) exhibited an improved power conversion efficiency (PCE) of 9.2%, which is higher than the pure and NS1 and NS3 WSe2 blended active layer-encompassing devices. The improved PCE is attributed to the synergic enhancement of exciton dissociation and an improvement in the charge mobility through the modified active layer for polymer solar cells. Furthermore, the highest sensitivity of 2.97 mA/Gy·cm2 was achieved for the NS2 WSe2 NSs blended active layer detected by X-ray exposure over the pure polymer, and with the NS1 and NS2 WSe2 blended active layer. These results led to the use of transition metal dichalcogenide materials in polymer solar cells and X-ray detectors.
| S-EPMC8230459 | biostudies-literature
Project description:Current technologies for X-ray detection rely on scintillation from expensive inorganic crystals grown at high-temperature, which so far has hindered the development of large-area scintillator arrays. Thanks to the presence of heavy atoms, solution-grown hybrid lead halide perovskite single crystals exhibit short X-ray absorption length and excellent detection efficiency. Here we compare X-ray scintillator characteristics of three-dimensional (3D) MAPbI3 and MAPbBr3 and two-dimensional (2D) (EDBE)PbCl4 hybrid perovskite crystals. X-ray excited thermoluminescence measurements indicate the absence of deep traps and a very small density of shallow trap states, which lessens after-glow effects. All perovskite single crystals exhibit high X-ray excited luminescence yields of >120,000 photons/MeV at low temperature. Although thermal quenching is significant at room temperature, the large exciton binding energy of 2D (EDBE)PbCl4 significantly reduces thermal effects compared to 3D perovskites, and moderate light yield of 9,000 photons/MeV can be achieved even at room temperature. This highlights the potential of 2D metal halide perovskites for large-area and low-cost scintillator devices for medical, security and scientific applications.
| S-EPMC5111063 | biostudies-literature
Project description:The sensitization of scintillation was investigated in crosslinked polymeric composite materials loaded with luminescent gold clusters aggregates acting as sensitizers, and with organic dye rhodamine 6G as the emitting species. The evolution in time of the excited states population in the systems is described by a set of coupled rate equations, in which steady state solution allowed obtainment of an expression of the sensitization efficacy as a function of the characteristic parameters of the employed luminescent systems. The results obtained indicate that the realization of sensitizer/emitter scintillating complexes is the strategy that must be pursued to maximize the sensitization effect in composite materials.
| S-EPMC8704871 | biostudies-literature
Project description:Typical polyol-based synthesis of silver nanowire employs insulating polymer as a surfactant for the silver nanowire growth, which limits direct contact between each nanowire and thus its optoelectronic properties. We herein demonstrate that a simple solvent treatment effectively removes the insulating polymer around Ag NWs, leading to significantly decreased sheet resistance (~12 Ω/sq) with an increased transmittance (81% @ T550), as compared to other post-treatments. We successfully demonstrate the transparent film heaters using the solvent-treated Ag NWs network, which rapidly exhibited 150 °C under a bias of 5 V. Flexible film heaters on plastic substrate is also demonstrated, suggesting a great potential of the solvent treatment process of Ag NWs for flexible transparent electrode and film heater applications.
| S-EPMC7919462 | biostudies-literature
Project description:Scintillators that exhibit X-ray-excited luminescence have great potential in radiation detection, X-ray imaging, radiotherapy, and non-destructive testing. However, most reported scintillators are limited to inorganic or organic crystal materials, which have some obstacles in repeatability and processability. Here we present a facile strategy to achieve the X-ray-excited organic phosphorescent scintillation from amorphous copolymers through the copolymerization of the bromine-substituted chromophores and acrylic acid. These polymeric scintillators exhibit efficient X-ray responsibility and decent phosphorescent quantum yield up to 51.4% under ambient conditions. The universality of the design principle was further confirmed by a series of copolymers with multi-color radioluminescence ranging from green to orange-red. Moreover, we demonstrated their potential application in X-ray radiography. This finding not only outlines a feasible principle to develop X-ray responsive phosphorescent polymers, but also expands the potential applications of polymer materials with phosphorescence features.
| S-EPMC9271082 | biostudies-literature
Project description:Scintillators emit visible luminescence when irradiated with X-rays. Given the unlimited tissue penetration of X-rays, the employment of scintillators could enable remote optogenetic control of neural functions at any depth of the brain. Here we show that a yellow-emitting inorganic scintillator, Ce-doped Gd3(Al,Ga)5O12 (Ce:GAGG), can effectively activate red-shifted excitatory and inhibitory opsins, ChRmine and GtACR1, respectively. Using injectable Ce:GAGG microparticles, we successfully activated and inhibited midbrain dopamine neurons in freely moving mice by X-ray irradiation, producing bidirectional modulation of place preference behavior. Ce:GAGG microparticles are non-cytotoxic and biocompatible, allowing for chronic implantation. Pulsed X-ray irradiation at a clinical dose level is sufficient to elicit behavioral changes without reducing the number of radiosensitive cells in the brain and bone marrow. Thus, scintillator-mediated optogenetics enables minimally invasive, wireless control of cellular functions at any tissue depth in living animals, expanding X-ray applications to functional studies of biology and medicine.
| S-EPMC8298491 | biostudies-literature