SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4426-y
Biomedical Mg alloys are candidate biodegradable metals for orthopedic and cardiovascular implants, yet their in vivo service life is governed by coupled mechanical-chemical attack that accelerates loss of mechanical integrity. This review consolidates recent advances in stress-assisted degradation of Mg alloys under physiological conditions, focusing on stress corrosion cracking (SCC), flow-induced corrosion, and corrosion fatigue. Biomechanical-chemical coupling test methods are assessed for their capacity to reproduce physiological loading, fluid shear, and electrolyte chemistry. Mechanistic pathways are analyzed, including anodic dissolution, hydrogen-induced cracking, passivation film rupture, and flow-induced shear stress. Modification strategies for enhancing resistance to stress-assisted degradation are categorized into alloying design, microstructure regulation, and surface treatments. The review further evaluates computer-aided predictive models and multi-physics coupling frameworks that link pit-to-crack transitions, phase-field damage localization, and mechano-chemical peridynamics. Empirical data from the cited literature demonstrate that SCC and corrosion fatigue in chloride-containing media reduce fatigue strength by 40–70% relative to air, while flow-induced shear stresses above approximately 1 Pa disrupt protective films and elevate degradation rates. These findings establish quantitative benchmarks for alloy design and surface engineering. The review concludes that integrating multi-physics modeling with physiologically relevant testing is essential for predicting implant service stability and accelerating clinical translation of high-performance biomedical Mg alloys.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025011302
Heavy metal contamination in soil severely compromises the quality and safety of Alisma orientale medicinal materials, and consumption of contaminated herbal preparations poses health risks. To characterize contamination and risks in Sichuan's genuine producing areas, 159 paired soil and plant samples were collected. Concentrations of Cu, Zn, Pb, Cd, and Ni were determined via ICP-OES. Soil pollution was assessed using the Single Pollution Index (Pi), Nemerow Comprehensive Index (Pn), and Potential Ecological Risk Index (RI). Human health risks from heavy metals in Alisma were evaluated via Target Hazard Quotient (THQ) and Hazard Index (HI). Mean soil concentrations were Cu 29.57, Zn 61.86, Pb 29.51, Cd 1.77, and Ni 28.08 mg·kg−1. Except for Cd, all elements were below agricultural soil screening values. Pi and Pn confirmed Cd contamination, with Cd posing slight to strong potential ecological risks. Cu, Cd, Pb, and Ni showed highly significant positive correlations, indicating common origins. Heavy metal concentrations in Alisma did not exceed pharmacopeial limits. The plant exhibited strong Zn enrichment but weak accumulation of Cu, Cd, and Pb, and negligible Ni enrichment. THQ and HI values indicated no potential health risks under current exposure. Quantitative assessment is critical for soil pollution control, safe cultivation, and medication safety.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3992-y
Two-dimensional (2D) materials exhibit excellent electrical, optical, and mechanical properties, yet precise control over chiral 2D materials remains a significant challenge. This work introduces asymmetric side chain engineering to prepare helically grooved poly(3,5-disubstituted phenylacetylene)s (PPAs) and investigates the effect of their asymmetric contour on tailoring 2D nanostructures. Post-polymerization modification of a common platform polymer efficiently produced a series of rigid helical PPAs with varying alkyl side chain lengths while maintaining identical degrees of polymerization and distribution. Increasing side chain asymmetry yielded anisotropic hexagonal platelets with progressively higher aspect ratios, whereas symmetric side chains formed regular 2D hexagonal sheets. Notably, the largest side chain asymmetry generated supramolecular structures with distinct chiral vortices. Computational simulations elucidated different self-assembly mechanisms, revealing that vortex-like assemblies are kinetically stabilized rather than thermodynamically stable. All 2D assemblies exhibited significantly enhanced circularly polarized luminescence (CPL) compared to discrete polymer solutions, with dissymmetry factors (g_lum) reaching as high as 0.1. This work establishes side chain asymmetry as a crucial factor for programming supramolecular chirality and opens new avenues for developing advanced chiroptical materials.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3894-9
Photocatalytic production of hydrogen peroxide (H2O2) using water and O2 offers an economical, environmentally friendly, and sustainable route for H2O2 synthesis. However, current photocatalytic systems suffer from poor charge carrier transport, narrow light absorption, and insufficient active sites, leading to unsatisfactory H2O2 production efficiency. In this study, a CoS/ZnIn2S4 (ZIS) composite was constructed by in-situ growing CoS nanoclusters on ZIS via a solvothermal method for photocatalytic H2O2 production. The integration of CoS with ZIS broadened the light absorption spectrum. The optimized CoS/ZIS-3 composite exhibited an exceptional H2O2 production rate of 2693.39 μmol g−1 h−1 under visible light in isopropanol, surpassing pristine ZIS and CoS by factors of 6.54 and 18.08, respectively. The S-scheme heterojunction and built-in electric field synergistically enhanced the separation and transportation of photogenerated charge carriers, thereby improving photocatalytic efficiency. The H2O2 synthesis mechanism involves dual-channel oxygen reduction and water oxidation reactions mediated by CoS/ZIS. The produced H2O2 effectively degraded organic pollutants and inhibited the growth of E. coli. This study presents a promising green strategy for enhancing ZIS-based photocatalysts through constructing S-scheme heterojunctions for efficient H2O2 synthesis.