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The effects of topological constraints on penetration structures of semi-flexible ring polymers in a melt are investigated using molecular dynamics simulations, considering simultaneously the effects of the chain stiffness. Three topology types of rings are considered: 0-knot (the unknotted), 3-knot and 6-knot ring polymers, respectively. With the improved algorithm to detect and quantify the inter-ring penetration (or inter-ring threading), the degree of ring threading does not increase monotonously with the chain stiffness, existing a peak value at the intermediate stiffness. It indicates that rings interpenetrate most at intermediate stiffness where there is a balance between coil expansion (favoring penetrations) and stiffness (inhibiting penetrations). Meanwhile, the inter-ring penetration would be suppressed with the knot complexity of the rings. The analysis of effective potential between the rings provides a better understanding for this non-monotonous behavior in inter-ring penetration.
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http://dx.doi.org/10.3390/polym12112659 | DOI Listing |
Beilstein J Org Chem
September 2025
Chemistry and Materials Program, College of Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Kohto-ku, Tokyo 135-8548, Japan.
In single crystals of C-N atropisomeric -(2-halophenyl)quinolin-2-one and the thione analogue, a unique association based on a halogen-π interaction was detected. In racemic and optically pure -(2-bromo- or 2-chlorophenyl)quinolin-2-ones, homochiral layered polymers, which consist of ()- or ()-atropisomers, were formed through intermolecular halogen-π association. The halogen-π association in the racemates is due to a halogen bond (C-X···π) between a σ-hole on the halogen atom and a π-electron on the quinolinone benzene ring, while that in optically pure forms is caused by an n-π* interaction between a lone electron pair on the halogen atom and a π* orbital of the quinolinone.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
Department of Organic and Nano Engineering, and Human-Tech Convergence Program, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
Photomultiplication-type organic photodetectors (PM-type OPDs) have recently attracted attention. However, the development of polymer donors specifically tailored for this architecture has rarely been reported. In this study, we synthesized benzobisoxazole-based polymer donors incorporating alkylated π-spacers that simultaneously enhance photocurrent density () and suppress dark current density (), leading to high responsivity () and specific detectivity (*).
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
Instituto de Cerámica y Vidrio (ICV-CSIC), C/Kelsen 5, 28049 Madrid, Spain.
The oxygen reduction reaction (ORR) is critical to energy conversion technologies and requires efficient catalysts for superior performance. Herein, nitrogen-doped carbide-derived carbon (N-CDC) catalysts are prepared using novel engineered molecular architectures based on polymer-derived ceramic technology. The obtained catalyst materials show a surface N concentration of >5 wt % and a hierarchically porous structure, resulting in a specific surface area of over 2000 m g.
View Article and Find Full Text PDFJ Mater Chem B
September 2025
School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China.
Antibacterial photodynamic therapy offers a promising approach for combating both susceptible and multidrug-resistant pathogens. However, conventional photosensitizers have limitations in terms of poor binding specificity and weak penetration for pathogens. In this study, we developed synergistic photobactericidal polymers that integrate hydrophilic toluidine blue O (TBO) with the lipophilic penetration enhancer citronellol (CT).
View Article and Find Full Text PDFChemistry
September 2025
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
Sequence-controlled polyester-based alternating copolymers have attracted significant interest due to their biocompatibility, biodegradability, closed-loop recyclability, and hydrolytic degradability, offering broad potential in biomedical and sustainable materials. Among the available strategies, regioselective ring-opening polymerization (ROP) of asymmetric cyclic di(thio)esters and cyclic(ester-amide)s has emerged as a promising approach for constructing alternating copolymers with precise sequence- and stereo-control, structural diversity, and tunable properties. This review classifies asymmetric cyclic monomers into two categories: (1) monomers with two aliphatic ester bonds, where regioselectivity is mainly dictated by steric differences and typically requires tailored metal catalysts; and (2) monomers with chemically distinct reactive sites (e.
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