End-group fidelity is the most important property for end-functional polymers. Compared to other controlled living polymerization methods, reversible addition-fragmentation chain transfer (RAFT) polymerization often yields polymers with a lower end-group fidelity, which greatly affects their applications. Herein, we report a staged-thermal-initiation RAFT polymerization for the synthesis of polymers with high thiol end-group fidelity and their high efficiencies for grafting to various gold nanoparticles (GNPs). We experimentally prove that the decrease of end-group fidelity with their molecular weight is caused by the gradual decomposition of the initiator rather than the degradation of chain-transfer agents. We show that the staged-thermal-initiation RAFT polymerization is more effective for synthesis of polymers with high thiol end-group fidelity. The grafting-to assays for various GNPs illustrate the positive correlation between the end-group fidelity of polymers and grafting-to efficiency. This work highlights the prospects for synthesis of high end-group fidelity polymers and their application in the preparation of nanoparticles-polymer hybrid materials.
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http://dx.doi.org/10.1021/acs.jpclett.1c01039 | DOI Listing |
Angew Chem Int Ed Engl
December 2024
ETH Zurich, Materials, Vladimir-Prelog-Weg 1-5/10, 8093, Zürich, SWITZERLAND.
Photoiniferter (PI) is a promising polymerization methodology, often used to overcome restrictions posed by thermal reversible addition-fragmentation chain-transfer (RAFT) polymerization. However, in the overwhelming majority of reports, high energy UV irradiation is required to effectively trigger photolysis of RAFT agents and facilitate the polymerization, significantly limiting its potential, scope, and applicability. Although visible light PI has emerged as a highly attractive alternative, most current approaches are limited to the synthesis of lower molecular weight polymers, and typically suffer from prolonged reaction times, extended induction periods, and higher dispersities.
View Article and Find Full Text PDFMacromol Rapid Commun
November 2024
Center for Soft Condensed Matter Physics and Interdisciplinary Research & Jiangsu Key Laboratory of Frontier Material Physics and Devices, School of Physical Science and Technology, Soochow University, Suzhou, 215006, P. R. China.
In recent years, the fully oxygen-tolerant reversible addition-fragmentation chain transfer (RAFT) polymerization has been emerging as a versatile and powerful tool for preparing well-defined polymers. In this contribution, the symmetrical diethyl xanthogen disulfide (XD) is successfully used as an initiator, chain transfer agent, and termination (iniferter) agent to directly regulate the open-to-air RAFT polymerization. The high end-group fidelity of polymer demonstrated by nuclear magnetic resonance (H-NMR) and matrix-assisted laser desorption/ionization time-of-flight mass spectra indicates that sulfur-centered xanthate radical can initiate and regulate RAFT polymerization of methacrylate (MA) under open conditions.
View Article and Find Full Text PDFAdv Mater
July 2024
Life-Like Materials and Systems, Department of Chemistry, University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany.
The integration of molecular machines and motors into materials represents a promising avenue for creating dynamic and functional molecular systems, with potential applications in soft robotics or reconfigurable biomaterials. However, the development of truly scalable and controllable approaches for incorporating molecular motors into polymeric matrices has remained a challenge. Here, it is shown that light-driven molecular motors with sensitive photo-isomerizable double bonds can be converted into initiators for Cu-mediated controlled/living radical polymerization enabling the synthesis of star-shaped motor-polymer conjugates.
View Article and Find Full Text PDFChem Sci
March 2024
Laboratory of Polymeric Materials, Department of Materials, ETH Zürich Zürich Switzerland
The synthesis of multiblock copolymers has emerged as an efficient tool to not only reveal the optimal way to access complex structures and investigate polymer properties but also to ascertain the end-group fidelity of a given polymerization methodology. Although reversible addition-fragmentation chain-transfer (RAFT) polymerization is arguably the most dominant strategy employed, its success is often hampered by the unavoidable and excessive use of radical initiators which results in increased termination and loss of end-group fidelity. In this work, we employ acid in RAFT polymerization to enhance the synthesis of multiblock copolymers.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2024
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China.
Microneedle patches are easy-to-use medical devices for transdermal administration. However, the insufficient insertion of microneedles due to the gap between planar patches and contoured skin affects drug delivery. Herein, we formulate a prepolymer for high-fidelity three-dimensional (3D) printed personalized transdermal patches.
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