New Carbon Materials•2026•DOI: 10.1016/S1872-5805(26)61073-6
Elastomers are widely used in engineering but suffer degradation when exposed to heat, ozone, UV radiation, and chemicals. To enhance performance for specific industrial applications, blending with other materials is common. In this study, chloroprene rubber (CR) was blended with brominated butyl rubber (BIIR) and reinforced with Ketjenblack (KB) at concentrations up to 20%. KB exhibits a porous, fluffy morphology with a high specific surface area of 1347 m²/g. Tensile tests were conducted before and after exposure to UV, ozone, saline, petrol, and diesel environments, and retention capacity was evaluated per ASTM standards. Transmission electron microscopy confirmed uniform dispersion of KB filler. Tribological and barrier property studies identified 10% KB as optimal due to uniform dispersion. Thermal degradation kinetics were analyzed using Kissinger–Akahira–Sunose modeling to determine activation energy. Dynamic mechanical analysis indicated a 5 °C reduction in glass transition temperature for the 20% composite. These elastomeric blends demonstrate potential as advanced materials for harsh industrial applications.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202506005
The escalating generation of medical waste, driven by healthcare expansion and frequent medical activities, poses significant environmental and public health risks. Under the framework of ecological civilization, China is developing a comprehensive policy system for medical waste treatment and disposal, yet the current framework remains nascent and exhibits inconsistencies between national and local policies. This study systematically analyzes the status of national and local policies from 2003 to 2024, collecting 413 policy documents (166 from national ministries and 247 from provincial governments). The analysis examines temporal evolution, regional distribution, and policy focus, alongside the influence of medical waste output, treatment technologies, facility infrastructure, and major epidemic responses. Findings reveal distinct policy phases: initial self-disposal, exploratory management, foundational system building, and rapid development. Regional disparities are pronounced, with eastern coastal areas showing more advanced policies due to greater technical and financial resources. The surge in medical waste, particularly during the COVID-19 pandemic, underscores the need for enhanced regulatory guidance. Non-incineration technologies are gaining traction for their environmental and cost benefits, and facility coverage has improved but remains uneven. The study proposes five policy principles to foster technological innovation and industrial upgrading, ensuring safe medical waste management and environmental protection.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025022704
Secondary inorganic aerosols (SNA), comprising sulfate, nitrate, and ammonium, are critical contributors to PM2.5 pollution in the Fenwei Plain, yet their formation mechanisms remain poorly characterized. Wintertime observations in Taiyuan revealed SNA as the dominant PM2.5 component, with a mean mass concentration of 33.19 ± 18.72 μg m−3, accounting for 47.13% of total PM2.5 mass. SNA concentrations increased markedly with pollution severity, but even under relatively clean conditions, SNA maintained a high mass fraction. Diurnal variation and correlation analyses indicated that nitrate formation pathways differed between day and night, largely governed by relative humidity (RH). During daytime, high RH (>55%) facilitated the partitioning of gaseous HNO3 to particulate nitrate. At night, RH positively correlated with nitrate concentration and nitrogen oxidation rate (NOR), with increased aerosol liquid water content (AWC) promoting NO2-to-nitrate conversion. The PM2.5 pH ranged from 4.3 to 5.2, and sulfate formation was primarily driven by H2O2 oxidation, with NO2 oxidation as a secondary pathway. These findings enhance understanding of SNA formation in the Fenwei Plain and provide a scientific basis for air quality policy.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025042304
To characterize the spatial variability of PM2.5 chemical components at the urban scale, ambient PM2.5 samples were collected from eight sites across Changsha, China. Samples were analyzed using ion chromatography, elemental carbon/organic carbon (EC/OC) analysis, and X-ray fluorescence (XRF) spectroscopy. Results showed that PM2.5 concentrations in urban areas were significantly higher than in suburban locations, with notably elevated levels at Changsha New Railway Station and Mapoling. Across different PM2.5 pollution levels, the eight sites exhibited pronounced spatial differences in concentration while sharing similar chemical compositions. Source apportionment identified secondary nitrate, vehicle emissions, and secondary sulfate as major contributors to PM2.5. The spatial distribution of these sources varied distinctly: secondary nitrate showed lower contributions in central areas but higher in western and southeastern regions; secondary sulfate was more prominent in the southeast, while vehicle emissions contributed more in the southeast and less in the west. Additionally, aerosol liquid water content promoted the secondary formation of nitrate and sulfate, exacerbating PM2.5 pollution. Secondary organic carbon was elevated in areas with high pedestrian density, suggesting enhanced secondary organic aerosol formation under intensive human activity. The study provides insights for targeted pollution control strategies in Changsha and similar cities.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4121-9
Perovskite solar cells (PSCs) are a promising photovoltaic technology, yet their commercialization is hindered by insufficient long-term operational stability under real-world conditions. While progress has improved resilience against static stressors (constant heat, electrical bias, humidity), durability under dynamic outdoor environments—particularly diurnal light cycling and temperature fluctuations—remains inadequately understood. Cyclic illumination induces interfacial expansion and contraction, leading to mechanical stress accumulation and grain-boundary (GB) fragmentation, ultimately decomposing the perovskite into Pb2+ and inactive phases. To address this, Zhang et al. propose a dynamic GB-resilience strategy integrating a photoswitchable isomeric compound, 4-(phenylazo) benzoic acid (Ca-Abz), into triple-cation lead-based perovskite grain boundaries. In the dark, Ca-Abz adopts a planar trans (E) configuration, anchoring via carboxylic acid-Pb2+ coordination. Under UV illumination, electronic excitation lowers the rotational barrier of the azo bond, triggering a transition to a sterically twisted cis (Z) configuration. This reversible molecular switching dynamically accommodates periodic lattice expansion and contraction, dissipating intergranular stress and regulating local strain. Density functional theory and first-principles molecular dynamics simulations show the Z isomer binds slightly stronger to the perovskite surface (−11.01 eV) than the E isomer (−10.99 eV), indicating illumination actively strengthens passivation. This approach represents a shift from static passivators to stimuli-responsive interfacial regulators that utilize UV energy to stabilize grain boundaries during lattice expansion, offering a promising route to enhance PSC operational stability under cyclic illumination.