Emergence of a Radical-Stabilizing Metal-Organic Framework as a Radio-photoluminescence Dosimeter.

Radio-photoluminescence (RPL) materials display a distinct radiation-induced permanent luminescence center, and therefore find application in the detection of ionizing radiation. The current inventory of RPL materials, which were discovered by serendipity, has been limited to a small number of metal-ion-doped inorganic materials. Here we document the RPL of a metal-organic framework (MOF) for the first time: X-ray induced free radicals are accumulated on the organic linker and are subsequently stabilized in the conjugated fragment in the structure, while the metal center acts as the X-ray attenuator. These radicals afford new emission features in both UV-excited and X-ray excited luminescence spectra, making it possible to establish linear relationships between the radiation dose and the normalized intensity of the new emission feature. The MOF-based RPL materials exhibit advantages in terms of the dose detection range, reusability, emission stability, and energy threshold. Based on a comprehensive electronic structure and energy diagram study, the rational design and a substantial expansion of candidate RPL materials can be anticipated.

High-Performance Sheet-Type Sulfide All-Solid-State Batteries Enabled by Dual-Function Li4.4Si Alloy-Modified Nano Silicon Anodes.

The silicon-based anodes are one of the promising anodes to achieve the high energy density of all-solid-state batteries (ASSBs). Nano silicon (nSi) is considered as a suitable anode material for assembling sheet-type sulfide ASSBs using thin free-standing Li6PS5Cl (LPSC) membrane without causing short circuit. However, nSi anodes face a significant challenge in terms of rapid capacity degradation during cycling. To address this issue, dual-function Li4.4Si modified nSi anode sheets are developed, in which Li4.4Si serves a dual role by not only providing additional Li+ but also stabilizing the anode structure with its low Young's modulus upon cycling. Sheet-type ASSBs equipped with the Li4.4Si modified nSi anode, thin LPSC membrane, and LiNi0.83Co0.11Mn0.06O2 (NCM811) cathode demonstrate exceptional cycle stability, with a capacity retention of 96.16% at 0.5 C (1.18 mA cm-2) after 100 cycles and maintain stability for 400 cycles. Furthermore, a remarkable cell-level energy density of 303.9 Wh kg-1 is achieved at a high loading of 5.22 mAh cm-2, representing a leading level of sulfide ASSBs using electrolyte membranes at room temperature. Consequently, the chemically stable slurry process implemented in the fabrication of Li4.4Si-modified nSi anode sheet paves the way for scalable applications of high-performance sulfide ASSBs.

Efficient neutron radiation shielding by boron-lithium imidazolate frameworks.

Radiation protective materials are widely applied to avoid occupational hazards from either particle emissions or high-energy electromagnetic waves. Herein, we present a boron imidazolate framework (BIF) as a novel neutron shielding additive with high neutron capture cross-section elements B/Li and H. The BIF1-based epoxy resin matrix (Ep-BIF1) possesses high thermal stability and excellent resistance capacity. The neutron radiation shielding property was characterized using an Am-Be source, in which the thermal neutron shielding efficiency of Ep-BIF1 is notably higher than that of Ep-B4C with equal boron concentration, showing potential applications as an advanced efficient neutron radiation shielding composite.

Using γ-Ray Polymerization-Induced Assemblies to Synthesize Polydopamine Nanocapsules.

This work reports a simple and robust strategy for synthesis of polydopamine nanocapsules (PDA NCs). First, polymer assemblies were synthesized by a γ-ray-induced liquid-liquid (H2O-acrylate) interface polymerization strategy, in the absence of any surfactants. 1H nuclear magnetic resonance analysis and molecular dynamics simulation reveal that the generation of polymer assemblies largely depends on the hydrophilicity of acrylate and gravity of the oligomers at the interface. By virtue of the spherical structure and mechanic stability of the polymer assemblies, PDA NCs are next prepared by the interfacial polymerization of dopamine onto the assemblies, followed by the removal of templates by using ethanol. The polydopamine nanocapsules are shown to load and release ciprofloxacin (CIP, a model drug), such that the CIP-loaded PDA NCs are able to inhibit the growth of Escherichia coli.

Color-tunable X-ray scintillation based on a series of isotypic lanthanide-organic frameworks.

For the first time, we report intense X-ray scintillation enabled by a series of isotypic lanthanide (Eu and Tb) based metal-organic frameworks, initially showing a very efficient X-ray to visible light luminescence conversion. By systematic adjusting of the molar ratio of Eu3+ and Tb3+ in the same MOF structure as a traditional strategy for color-tuning in lanthanide-based photoluminescent materials, linear multicolor visualization of X-ray radiation from red to green can be facilely achieved, providing a new class of scintillating materials with continuous color tunability that can be customized for desired purposes. Moreover, these lanthanide-organic framework based scintillators exhibit excellent radiation resistance and humidity stability, in comparison with the state of the art and commercially-available X-ray scintillator, CsI:Tl.

Polyelectrolyte-based physical adhesive hydrogels with excellent mechanical properties for biomedical applications.

Physically crosslinked hydrogels were synthesized by copolymerization of acrylamide and acrylic acid monomers in the presence of cationic polyelectrolyte polydimethyldiallylammonium chloride. The fully physically crosslinked hydrogel showed good mechanical properties and good adhesion with a variety of substrates. These advantages can be attributed to the homogeneous distribution of crosslinking points due to hierarchical hydrogen bonds and electrostatic attractions in the hydrogel networks. Furthermore, these non-covalent bonds provided an effective pathway to dissipate energy. The mechanical properties of the hydrogels can be easily tuned by changing the chemical composition and ratio of monomers. We further showed that the transparent hydrogels were cytocompatible, and can be used for biomedical applications, including pH-triggered small molecule delivery and hydrogel-based hybrids for detecting doses of radiotherapy.

Polystyrene-based Hollow Microsphere Synthesized by γ-ray Irradiation-assisted Polymerization and Self-Assembly and Its Application in Detection of Ionizing Radiation.

To simply and multitudinously synthesize hollow microspheres in a pure system is important for relevant research and application. Here, a simple and novel one-pot synthetic strategy to prepare polystyrene (PS) hollow microspheres via irradiation-assisted free-radical polymerizing and self-assembly (IFPS) approach under γ-ray irradiation with no additives introduced into the system is presented. And PS/2,5-Diphenyloxazole (PPO) fluorescent microspheres have been prepared successfully by IFPS reaction, which can be used as scintillators for the detection of ionizing radiation. A linear relationship between emitted luminescence and dose-activity in water is obtained, which suggests that composite microspheres could be used as liquid scintillation in specific environment.

Laundering durable antibacterial cotton fabrics grafted with pomegranate-shaped polymer wrapped in silver nanoparticle aggregations.

To improve the laundering durability of the silver functionalized antibacterial cotton fabrics, a radiation-induced coincident reduction and graft polymerization is reported herein where a pomegranate-shaped silver nanoparticle aggregations up to 500 nm can be formed due to the coordination forces between amino group and silver and the wrapping procedure originated from the coincident growth of the silver nanoparticles and polymer graft chains. This pomegranate-shaped silver NPAs functionalized cotton fabric exhibits outstanding antibacterial activities and also excellent laundering durability, where it can inactivate higher than 90% of both E. coli and S. aureus even after 50 accelerated laundering cycles, which is equivalent to 250 commercial or domestic laundering cycles.

Laundering durability of photocatalyzed self-cleaning cotton fabric with TiO2 nanoparticles covalently immobilized.

Photocatalyzed self-cleaning cotton fabrics with TiO2 nanoparticles covalently immobilized are obtained by cograft polymerization of 2-hydroxyethyl acrylate (HEA) together with the surface functionalized TiO2 nanoparticles under γ-ray irradiation. The covalent bonds between the TiO2 nanoparticles and cotton fabrics bridged by poly(2-hydroxyethyl acrylate) (PHEA) graft chains is strong enough to survive 30 accelerated laundering circles, equivalent to 150 commercial or domestic launderings.