Rotaxanes consisting of a high-molecular-weight axle and wheel components (macro-rotaxanes) have high structural freedom, and are attractive for soft-material applications. However, their synthesis remains underexplored. Here, we investigated macro-rotaxane formation by the topological trapping of multicyclic polydimethylsiloxanes (mc-PDMSs) in silicone networks. mc-PDMS with different numbers of cyclic units and ring sizes was synthesized by cyclopolymerization of a α,ω-norbornenyl-functionalized PDMS. Silicone networks were prepared in the presence of 10-60 wt % mc-PDMS, and the trapping efficiency of mc-PDMS was determined. In contrast to monocyclic PDMS, mc-PDMSs with more cyclic units and larger ring sizes can be quantitatively trapped in the network as macro-rotaxanes. The damping performance of a 60 wt % mc-PDMS-blended silicone network was evaluated, revealing a higher tan δ value than the bare PDMS network. Thus, macro-rotaxanes are promising as non-leaching additives for network polymers.
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http://dx.doi.org/10.1002/anie.202304493 | DOI Listing |
Molecules
January 2025
Centre for Surface Chemistry and Catalysis-Characterization and Application Team (COK-KAT), KU Leuven, Celestijnenlaan 200F Box 2461, 3001 Heverlee, Belgium.
This work describes the synthesis of ordered 3D siloxane-silsesquioxane reticular materials with silicate D4R cubes (SiO), harvested from a sacrificial tetrabutylammonium cyclosilicate hydrate (TBA-CySH) precursor, interlinked with octyl and dicyclopentyl (Cp) hydrocarbon functionalities in a one-step synthesis with organodichlorosilanes. Advanced solid-state NMR spectroscopy allowed us to unravel the molecular order of the nodes and their interconnection by the silicone linkers. In the case of octyl-methyl silicone linkers, changing the silane-to-silicate ratio in the synthesis allowed for tuning the length of the linker between the nodes.
View Article and Find Full Text PDFBiomolecules
January 2025
Department of Surgery and Specialties, Central University Hospital of Asturias, Faculty of Medicine and Health Sciences, University of Oviedo, 33011 Oviedo, Spain.
The aim of the circular economy is to treat waste as a valuable raw material, reintegrating it into the industrial economy and extending the lifecycle of subsequent products. Efforts to reduce the production of hard-to-recycle waste are becoming increasingly important to manufacturers, not only of consumer goods but also of specialized items that are difficult to manufacture, such as medical supplies, which have now become a priority for the European Union. The purpose of the study is to manufacture a novel human-purified type I collagen membrane from bone remnants typically discarded during the processing of cortico-cancellous bones in tissue banks and to evaluate its mechanical properties and effectiveness in regenerating bone-critical mandibular defects in rabbits.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, Maharashtra, India.
Water-in-oil emulsions are critical in various fields, including food, agriculture, personal care, and pharmaceuticals. In some situations, spontaneous emulsification occurs in emulsions with high concentrations of oil-soluble surfactants, in which the parent water drops fragment into finer droplets, forming a network near the interface, which exhibits interfacial elasticity. This study investigates this phenomenon using a water/Span 80-paraffin oil system.
View Article and Find Full Text PDFLangmuir
January 2025
Henan Province Engineering Technology Research Center of MEMS Manufacturing and Applications, School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China.
The rapid development of wearable technology, flexible electronics, and human-machine interaction has brought about revolutionary changes to the fields of motion analysis and physiological monitoring. Sensors for detecting human motion and physiological signals have become a hot topic of current research. Inspired by the muscle fiber structure, this paper proposed a highly stable strain sensor that was composed of stretchable Spandex fibers (SPF), multiwalled carbon nanotubes (MWCNTs), and silicone rubber (Ecoflex).
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
Silicone rubber (SiR) has a wide range of medical applications, but it lacks antimicrobial properties, leading to potential infection issues with related implants or medical devices. Most studies focus on adding anti-bacterial agents or surface modification, which usually result in composites with anti-bacterial properties, rather than synthesizing SiR with intrinsically antimicrobial performances. To tackle this issue, a double substituted bornyl-siloxane crosslinker (BC) is designed.
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