To enhance the radiation stability of silicone rubber (SR) and ensure its safe and reliable performance,hexagonal boron nitride (h-BN) was incorporated into SR as a functional filler. The effects of the filler amount and size on the mechanical properties,thermal stability,and radiation resistance of SR composites were investigated. The mechanism through which h-BN improved the radiation stability of SR was explored. The experimental results of stress-strain and hardness tests showed that the SR composite filled with 20 parts of h-BN (BN/SR-20) exhibited excellent mechanical properties. The tensile strength,100% constant tensile stress (S100),and hardness of BN/SR-20 improved by 5.9%,69.1%,and 15.6%,respectively,compared with those of unfilled SR (SR-U). BN/SR-20 displayed higher radiation resistance than SR-U,and its tensile strength and S100 were significantly better than those of SR-U in an ionizing-radiation environment. A larger transverse size of h-BN was found to be more effective in slowing down the radiation-aging process of SR. In addition,gas chromatography analysis of the radiolytic gas (hydrogen) yield and oxygen consumption of the composites and free-radical-scavenging experiments revealed that the addition of h-BN reduced the diffusion rate of O2 in SR and enhanced the radiation resistance of the composites.

MXene/graphene oxide (GO) composites have broad application prospects in fields,such as energy,environment,and biomedicine. In this study,few-layer Ti3C2Tx was mixed with GO,which was then reduced and surface-modified using γ-ray radiation. Simultaneously,a composite hydrogel (M/rGO) was prepared by self-assembly from the interaction between the surface groups of reduced graphene oxide (rGO) and the oxygen-containing functional groups on the surface of Ti3C2Tx. The M/rGO-75 composite hydrogel prepared at an absorbed dose of 75 kGy exhibited a uniform three-dimensional network structure. The hydrogel was further freeze-dried and annealed to remove surface oxygen-containing functional groups and prepare a new composite aerogel (H-M/rGO),which maintained the original network structure. The prepared H-M/rGO electrode was used as a supercapacitor electrode. The optimized and synthesized H-M/rGO-75 composite aerogel exhibited a mass-specific capacitance of 119 F/g at a current density of 1 A/g,which was significantly higher than those of GO and aerogels without MXene. In addition,it exhibited excellent rate performance,conductivity,and cycling stability.

Temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) was grafted onto the surface of graphene oxide (GO) via reversible addition-fragmentation chain transfer polymerization initiated by γ-ray radiation. Raman spectroscopy and X-ray photoelectron spectroscopy analyses indicated that GO was reduced synchronously upon the radiation grafting polymerization of NIPAAm in an aqueous solution. A pulse radiolysis study demonstrated that NIPAAm reacted with both hydrated electrons (eaq-) and hydroxyl radicals (OH) produced by water radiolysis of which the reaction rate constants were 1.0×1010 L/(mol?s) and (4.3±0.2)×109 L/(mol?s),respectively. The addition reaction between NIPAAm and OH produces a radical at the unsaturated double bond of NIPAAm,which initiates the free radical polymerization of the monomers. Meanwhile,the reaction between NIPAAm and eaq- not only consumes strongly reductive eaq- but also produces weakly reductive radical anion intermediates,which decreases the reduction degree of rGO. The residual oxygen-containing groups on the surface of rGO with a low degree of reduction degree,such as carboxyl groups,endowed rGO-g-PNIPAAm with good pH responsiveness. Compared to pristine GO without PNIPAAm grafting,rGO-g-PNIPAAm which prepared with an absorbed dose of 3.6 kGy for radiation grafting polymerization exhibited a 30% higher photothermal conversion efficiency under near-infrared LASER irradiation. This study provides a convenient and controllable method for preparing photothermal conversion materials with pH and temperature dual responsiveness.

This article describes the preparation of continuous metal-organic framework (MOF) Zn(bdc)(dabco)?0.5 membranes on flexible polymer substrates using a radiation-induced method. The morphologies and structures of the membranes were investigated using X-ray diffraction,Fourier-transform infrared spectroscopy,and scanning electron microscopy. Their light hydrocarbon-adsorption properties were characterized using Brunauer-Emmett-Teller specific surface area measurements,density functional theory pore-size analysis,and single-component adsorption isotherms. The results indicated that the Zn(bdc)(dabco)0.5 membranes exhibited higher adsorption for ethane and propane than for methane. Moreover,the Zn(bdc)(dabco)0.5 membranes showed enhanced ethane/methane selectivity (reaching 11 at atmospheric pressure) and propane/methane selectivity (reaching 10 at atmospheric pressure). This study demonstrates the unique advantages of MOF membranes in the field of separation.

To enhance the capacitive performance of supercapacitors,NiMoO4 electrode materials were synthesized by applying a molybdenum source to the nickel foam (NF) surface using irradiation technology. The morphology,microstructure,and electrochemical properties of the materials were optimized by varying the absorbed dose. The in situ synthesized NiMoO4 on an NF surface is an effective anode material for supercapacitors,demonstrating impressive energy storage capabilities. Its specific capacitance reaches 586.1 C/g at a current density of 1 A/g. It maintains a specific capacitance of 361.5 C/g at 15 A/g,resulting in a performance retention of 85.6%. Furthermore,the material retains a specific capacitance of 533.4 C/g with a capacity retention rate of 91.6% after 10 000 charge/discharge cycles,indicating strong cycling stability. The NiMoO4 electrode material was combined with activated carbon (AC) to create a hybrid supercapacitor,NiMoO4//AC. This device,operating at a maximum voltage of 1.7 V,exhibited a high energy density of 44.5 Wh/kg at a power density of 800.0 W/kg. The specific capacitance of the device remained at 93.2% after 5 000 charge/discharge cycles at a current density of 10 A/g. This study demonstrated that NiMoO4 electrode materials,prepared via irradiation,possess excellent electrochemical properties and significant application potential,offering a novel approach for designing high-efficiency,low-cost supercapacitor electrodes.

This study examines the changes in properties and aging mechanisms of polyphenylene oxide (PPO) foams under two densities when subjected to combined γ-radiation (0–1 kGy) and 3% compression. The investigation focuses on the effects of absorbed dose and compression on various characteristics,including the mechanical properties,thermal stability,thermal conductivity,surface morphology,and chemical structure of PPO foams. The types and yields of gases released during radiation exposure are revealed using gas-phase infrared spectroscopy. The results showed that the collapse and permanent deformation of the surface pore structure in PPO foams following γ radiation and compression aging significantly contribute to increase in elastic modulus and thermal conductivity. No significant changes were observed in the internal radicals or surface functional group structures of the samples before and after aging. The concentration of residual radicals within the samples was influenced by radiation-induced chemical changes and the absorbed dose. Upon radiation exposure and subsequent aging in an O2/N2 atmosphere,PPO foams emited CO2,CO,and alkanes. In addition,the CO2 yield of PPO foams after radiation-compression aging was slightly reduced due to the permanent deformation caused by compression,compared to γ-radiation aging alone. These findings hold significant value for the evaluation of γ-radiation–compression aging mechanisms and the lifespan of PPO foams.

In the clinical practice of radiotherapy,how to quickly,safely,accurately and economically monitor the irradiation dose or implement quality assurance measures before irradiation has always been a research hotspot in this research field. In this study,the reaction between nitrate ions and free radicals produced by water radiolysis was innovatively used as a dose-response mechanism. A radiation-grafted silica gel acrylic composite was selected as a matrix material to develop a tough radiation composite hydrogel dosimeter with high mechanical strength. The experimental results showed that the hydrogel dosimeter exhibited the best dose-response linear correlation under a sodium nitrate concentration of 0.5 mol/L and sodium formate concentration of 2.5×10-3 mol/L. In addition,the prepared hydrogel dosimeter not only exhibited excellent puncture resistance,non-brittleness,high pressure resistance,and adjustable mechanical properties,but also displayed impressive time stability in practical applications,indicating potential for commercialization.

This study leverages the ability of polytetrafluoroethylene (PTFE) to generate stable free radicals under ionizing radiation to develop a solid PTFE dosimeter sheet. Experimental results indicate a strong positive correlation between free radical response and absorbed dose over a broad range (1-180 kGy). The performance of the dosimeter was minimally influenced by dose rate and energy dependence,while the effects of irradiation temperature and post-irradiation storage time on free-radical decay exhibited clear and consistent patterns. Unlike conventional dosimeters used in the industry,the PTFE dosimeter is suitable for high-dose measurements and calibrations,covering a range of 1-180 kGy with a total uncertainty of less than 5.02%,demonstrating high metrological reliability. This study provides valuable insights into precise dose control and calibration in the irradiation processing of polymers and other functional materials.

The strong fluorescence of 7-hydroxycoumarin yielded by the reaction of coumarin with hydroxyl radicals (?OH) was used as a fluorescent probe to determine the yield of 7-hydroxycoumarin aqueous solutions with different concentrations of TBP and TiAP after gamma ray irradiation. The reaction rate constants of TBP and TiAP with ?OH at room temperature were determined via pseudo-first order kinetic fitting (kTBP= (9.0 ± 0.2) ×109 L/（mol·s）and kTiAP= (5.3 ± 0.2) ×109 L/（mol·s）),respectively. Owing to the stronger hydrophobicity of TiAP compared with that of TBP,its reaction rate constant with ?OH is lower than that of TBP,thus resulting in a higher yield of ?OH in the TiAP solution compared to the TBP solution with the same concentration. This study provides a simple,convenient and efficient method for investigating the reactions between extractants and ?OH.

在能源催化领域中，开发低成本、高丰度的高效非金属催化剂一直是光催化产氢反应的研究热点之一。氮化硼纳米片（BNNS）是优异的非金属二维材料，然而，传统化学方法难以突破其宽禁带将其转变为可见光响应催化剂。本工作提出，在环境温度和压力下，高能射线能够可控地构筑BNNS的内部缺陷，实现其可见光催化产氢性能。实验结果表明，经γ射线辐照后，BNNS的光催化产氢性能随吸收剂量的增加而明显提高。辐照后样品的最大产氢速率可达1 033.7 μmol/(g·h)，较化学法制备的缺陷氮化硼提高近两个数量级。进一步结构表征证实，辐射在BNNS中产生三硼中心缺陷，导致BNNS形成中间能级并提高了载流子分离效率，从而将BNNS由宽禁带半导体转变为可见光响应催化剂。本研究为BNNS在可见光催化领域的应用提供了全新思路，并展示出辐射技术在催化剂的可控缺陷构筑和活性调控中的独特作用。

Covalent organic frameworks (COFs) are an emerging class of emerging crystalline porous materials used in separation and purification,adsorption,catalysis,optoelectronics,and energy storage. COFs are often synthesized by conventional solvothermal processes that require repeated freeze-pump-thaw procedures,elevated temperatures,closed systems for high autogenous pressures,and long reaction periods; this greatly hampers their large-scale production. Additionally,large amounts of COFs are singly built with bare aromatic skeletons without subordinate functional groups,making them difficult to utilize. Ionizing radiation technology has the advantages of simple operation,mild conditions,and large-scale production,which has been widely used in the preparation and functionalization of materials. This review mainly summarizes the recent research progress in radiation technology for the synthesis and functionalization of COFs in recent years.

This article reviews recent studies on three-dimensional (3D) radiation dosimeter designs based on photonic crystals and other structure color materials. Photonic crystals and other structure color materials have a wide range of applications in fields such as medical detection,graphic printing,and anti-counterfeiting identification owing to their photonic bandgap properties and bright structural colors. The responsiveness of photonic crystals and other structure color materials to ionizing radiation has been exploited to develop a photonic crystal thin-film dosimeter than can achieve a full visible spectral shift of Bragg absorption peaks under X- or γ-ray irradiation. The dosimeter has a highly tunable application range and a spatial resolution exceeding 30 μm; moreover,it exhibits high environmental stability to light,temperature,and humidity. This study proposes three reading methods: spectrometer detection,naked-eye comparison with standard color cards,and mobile phone-based hue-value detection techniques. Additionally,the sensitivity of the photonic crystal dosimeter was improved by adding polyethylene glycol as a radiation-sensitive material. Gelatin methacrylate was used to prepare hydrogel films,which were chemically modified to introduce unsaturated vinyl groups to achieve sensitive response to X-rays. The hydrogel photonic crystal dosimeter demonstrated favorable dose-response performance on clinical radiotherapy equipment,which agrees well with the measurement results of commercial film dosimeters. Finally,the photonic crystal dosimeter was combined with three-dimensional printing technology to three-dimensionalize the hydrogel photonic crystal dosimeter,thus providing translational potential for topographic dose mapping in clinical radiotherapy. Meanwhile,new thin-film optical interference films have emerged,and the introduction of radiation-responsive groups such as modified double bonds,disulfides/diselenides/disulfides,and azo groups significantly improved their sensitivity and enabled simultaneous drug release under X-ray assistance. This study provides theoretical and technical foundation for the development of portable,real-time,wide-ranging,and high-spatial-resolution photonic crystal radiation dosimeters,which have demonstrated application potential,although their dose verification in actual medical radiotherapy is yet to be realized.

This review article highlights our group's use of γ-irradiation for crosslinking polyolefin systems and designing filled rubber systems. It emphasizes the application of synchrotron radiation and neutron scattering techniques for in situ studies on both material systems,providing an in-depth understanding of the relationship between the microstructure and properties of the materials. The article first illustrates how γ-ray irradiation initiates chemical reactions between polymer chains,promoting the formation of new chemical bonds to design and control the desired material systems. Based on this,our group has conducted in situ studies using major scientific facilities in China. These efforts not only showcase the advancements in the construction of major scientific facilities in China,including the three major neutron sources and synchrotron radiation sources,but also demonstrate the unique advantages of these facilities in promoting various fields,particularly in exploring the microstructure and dynamic processes of polymer-based materials.