Organic radical as a powerful tool has been extensively applied in synthetic chemistry. However, harnessing radical-mediated noncovalent interactions to fabricate soft materials remains elusive. Here we report a new c...Organic radical as a powerful tool has been extensively applied in synthetic chemistry. However, harnessing radical-mediated noncovalent interactions to fabricate soft materials remains elusive. Here we report a new category of supramolecular hydrogel system held by multiple radical-radical(polyradical) interactions, and its photosensitive cross-linking structure. A simple polyacrylamide with triarylamine(TAA)pendants is designed as the precursor. The TAA units in polymer can be converted into active TAA^(·+)radical cations with light and further associate each other via TAA^(·+)–TAA^(·+)stacking interactions to form stable supramolecular network. Temporal control of the light irradiation dictates the degree of radical stacks, thus regulating the mechanical performance of the resulting hydrogel materials on-demand. Moreover, the reversible collapse of this hydrogels can be promoted by adding radical scavenger or exerting reduction voltage.展开更多
基金fund support of the National Natural Science Foundation of China (Nos. 21674022 and 51703034)the National Defense Science and Technology Innovation Zone (No. 163 Program)the Shanghai Rising-Star Program (No. 19QA1400700)。
文摘Organic radical as a powerful tool has been extensively applied in synthetic chemistry. However, harnessing radical-mediated noncovalent interactions to fabricate soft materials remains elusive. Here we report a new category of supramolecular hydrogel system held by multiple radical-radical(polyradical) interactions, and its photosensitive cross-linking structure. A simple polyacrylamide with triarylamine(TAA)pendants is designed as the precursor. The TAA units in polymer can be converted into active TAA^(·+)radical cations with light and further associate each other via TAA^(·+)–TAA^(·+)stacking interactions to form stable supramolecular network. Temporal control of the light irradiation dictates the degree of radical stacks, thus regulating the mechanical performance of the resulting hydrogel materials on-demand. Moreover, the reversible collapse of this hydrogels can be promoted by adding radical scavenger or exerting reduction voltage.
