Oligo[2]catenane That Is Robust at Both the Microscopic and Macroscopic Scales

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(16), P. 9011 - 9020

Published: April 13, 2023

Polycatenanes are extremely attractive topological architectures on account of their high degrees conformational freedom and multiple motion patterns the mechanically interlocked macrocycles. However, exploitation these peculiar structural dynamic characteristics to develop robust catenane materials is still a challenging goal. Herein, we synthesize an oligo[2]catenane that showcases properties at both microscopic macroscopic scales. The key feature design controlling force-bearing points metal-coordinated core [2]catenane moiety able maximize energy dissipation via dissociation metal-coordination bonds then activation sequential intramolecular motions circumrotation, translation, elongation under external force. As such, level, single-molecule force spectroscopy measurement exhibits rupture in reaches record 588 ± 233 pN. At our manifests itself as toughest material ever reported (15.2 vs 2.43 MJ/m3). These fundamental findings not only deepen understanding structure-property relationship poly[2]catenanes with full set features but also provide guiding principle fabricate high-performance materials.

Language: Английский

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Insights into the Correlation of Cross‐linking Modes with Mechanical Properties for Dynamic Polymeric Networks

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(37)

Published: July 26, 2023

Simultaneously introducing covalent and supramolecular cross-links into one system to construct dually cross-linked networks, has been proved an effective approach prepare high-performance materials. However, so far, features advantages of networks compared with those possessing individual or cross-linking points are rarely investigated. Herein, on the basis comparison between polymer network (SPN), (CPN) (DPN), we reveal that dual strategy can endow DPN integrated CPN SPN. Benefiting from energy dissipative ability along dissociation host-guest complexes, shows excellent toughness ductility similar Meanwhile, elasticity in could rise structural stability a level comparable CPN, exhibiting quick deformation recovery capacity. Moreover, strongest breaking stress puncture resistance among three, proving unique property method. These findings gained our study further deepen understanding dynamic polymeric facilitate preparation elastomeric

Language: Английский

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Highly Recyclable and Tough Elastic Vitrimers from a Defined Polydimethylsiloxane Network

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(47)

Published: Oct. 3, 2023

Despite intensive research on sustainable elastomers, achieving elastic vitrimers with significantly improved mechanical properties and recyclability remains a scientific challenge. Herein, inspired by the classical elasticity theory, we present design principle for ultra-tough highly recyclable defined network constructed chemically crosslinking pre-synthesized disulfide-containing polydimethylsiloxane (PDMS) chains tetra-arm polyethylene glycol (PEG). The is achieved reduced dangling short relatively uniform molecular weight of strands. Such network, i.e., PDMS-disulfide-D, exhibit performance than random analogous, previously reported PDMS vitrimers, even commercial silicone-based thermosets. Moreover, unlike that show obvious loss in after recycling, those enable excellent thermal recyclability. PDMS-disulfide-D also deliver comparable electrochemical signals if utilized as substrates electromyography sensors recycling. multiple relaxation processes are revealed via unique physical approach. Multiple techniques applied to unravel microscopic mechanism such network.

Language: Английский

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Photoresponsive Rotaxane-Branched Dendrimers: From Nanoscale Dimension Modulation to Macroscopic Soft Actuators

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(26), P. 14498 - 14509

Published: June 16, 2023

Aiming at the construction of novel soft actuators through amplified motions molecular machines nanoscale, design and synthesis a new family photoresponsive rotaxane-branched dendrimers an efficient controllable divergent approach was successfully realized for first time. In third-generation dendrimers, up to 21 azobenzene-based rotaxane units located each branch, thus making them successful light-control integrated artificial machines. Notably, upon alternative irradiation with UV visible light, photoisomerization azobenzene stoppers leads collective precisely arranged units, resulting in reversible dimension modulation integrating solution. Moreover, macroscopic were further constructed based on these which revealed fast shape transformation behaviors actuating speed 21.2 ± 0.2° s-1 ultraviolet irradiation. More importantly, resultant could produce mechanical work light control that has been employed weight-lifting cargo transporting, laying foundation toward smart materials can perform programmed events.

Language: Английский

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Mechanically interlocked [an]daisy chain networks

Chem, Journal Year: 2023, Volume and Issue: 9(8), P. 2206 - 2221

Published: May 4, 2023

Language: Английский

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