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Entanglement plays a critical role in determining the dynamic properties of polymer systems, , resulting in slip links and pulley effects for achieving large deformation and high strength. Although it has been studied for decades, the mechanics of entanglements for stiffness-toughness conflict is not well understood. In this study, topological knot theory incorporating an extended tube model is proposed to understand the entanglements in a slide-ring (SR) gel, which slips over a long distance to achieve large deformation and high toughness the pulley effect. Based on topological knot theory, the sliding behavior and pulley effect of entanglements among molecular chains and cross-linked rings are thoroughly investigated. Based on rubber elasticity theory, a free-energy function is formulated to describe mechanical toughening and slipping of topological knots, while the SR gel retains the same binding energy. Finally, the effectiveness of the proposed model is verified using both finite element analysis and experimental results reported in the literature.
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http://dx.doi.org/10.1039/d1sm01737c | DOI Listing |
Adv Mater
September 2025
School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
Liquid crystal elastomers (LCEs) are important soft actuators that show strong promise in many fields where traditional rigid actuators or robotics are impractical. However, their real-world applications are lacking primarily due to inadequate actuation performance and complicated fabrication processes. Here, a novel design is reported that significantly enhances actuation performance while simplifying the fabrication process.
View Article and Find Full Text PDFInt J Womens Health
August 2025
Key Laboratory of Evidence Science (China University of Political Science and Law), Ministry of Education, Beijing, 100088, People's Republic of China.
Background: Umbilical cord hemorrhage (UCH) is a rare but catastrophic obstetric emergency associated with nearly 50% fetal mortality, and its precise pathogenic mechanisms remain elusive in clinical practice. The pathophysiological cascade involves hemorrhagic expansion from ruptured umbilical vessels predominantly the umbilical vein which generates compressive forces on adjacent umbilical arteries within the constrained Wharton's jelly. This acute vascular compromise precipitates the sudden cessation of fetoplacental circulation, culminating in irreversible hypoxic-ischemic injury.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
State Key Laboratory of Molecular Engineering of Polymers, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Shanghai, 200433, P.R. China.
Mechanically interlocked molecules (MIMs) exhibit unique properties and functions arising from their structural entanglement, features of which are absent in their individual components. However, synthesizing topologically complex architectures, particularly those with topological chirality, remains a significant challenge due to the lack of general methods for controlled entanglement. Herein, we report the stereoselective synthesis of a 24-metal-center topologically chiral [6]catenane featuring 18 crossings ( link), representing one of the most intricate MIMs constructed to date.
View Article and Find Full Text PDFSensors (Basel)
August 2025
Electronic Information School, Wuhan University, Wuhan 430072, China.
Flexible hydrogel sensors demonstrate emerging applications, such as wearable electronics, soft robots, and humidity smart devices, but their further application is limited due to their single-responsive behavior and unstable, low-sensitivity signal output. This study develops a dual-responsive starch-based conductive hydrogel via a facile "one-pot" strategy, achieving mechanically robust pressure sensing and ultra-sensitive humidity detection. The starch-Poly (2,3-dihydrothieno-1,4-dioxin)-poly (styrenesulfonate) (PEDOT:PSS)-glutaraldehyde (SPG) hydrogel integrates physical entanglement and covalent crosslinking to form a porous dual-network architecture, exhibiting high compressive fracture stress (266 kPa), and stable electromechanical sensitivity (ΔI/I, ~2.
View Article and Find Full Text PDFEntropy (Basel)
August 2025
Research Center for Astronomy and Applied Mathematics of the Academy of Athens, Soranou Efessiou 4, GR-11527 Athens, Greece.
We study in detail the critical points of Bohmian flow, both in the inertial frame of reference (Y-points) and in the frames centered at the moving nodal points of the guiding wavefunction (X-points), and analyze their role in the onset of chaos in a system of two entangled qubits. We find the distances between these critical points and a moving Bohmian particle at varying levels of entanglement, with particular emphasis on the times at which chaos arises. Then, we find why some trajectories are ordered, without any chaos.
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