Nature has engineered exquisitely responsive systems where molecular-scale information is transferred across an interface and propagated over long length scales. Such systems rely on multiple interacting, signalling and adaptable molecular and supramolecular networks that are built on dynamic, non-equilibrium structures. Comparable synthetic systems are still in their infancy. Here, we demonstrate that the light-induced actuation of a molecularly thin interfacial layer, assembled from a hydrophilic-azobenzene-hydrophobic diblock copolymer, can result in a reversible, long-lived perturbation of a robust glassy membrane across a range of over 500 chemical bonds. We show that the out-of-equilibrium actuation is caused by the photochemical trans–cis isomerization of the azo group, a single chemical functionality, in the middle of the interfacial layer. The principles proposed here are implemented in water-dispersed nanocapsules, and have implications for on-demand release of embedded cargo molecules.
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The authors thank the US Army Research Office for funding through the MURI program (W911NF-15-1-0568).
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Supplementary synthesis and characterization details and analysis, Schemes 1–3, and Figures 1–16
Real-time movie showing that no reaction occurred between hexamathylene diamine encapsulated within the aqueous lumen of the supramolecular capsule formed by P2 and sebacoyl chloride dissolved in hexane.
Real-time movie of nylon formation between hexamathylene released from the supramolecular capsule formed by P2 upon light irradiation and sebacoyl chloride dissolved in hexane.
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Molla, M.R., Rangadurai, P., Antony, L. et al. Dynamic actuation of glassy polymersomes through isomerization of a single azobenzene unit at the block copolymer interface. Nature Chem 10, 659–666 (2018). https://doi.org/10.1038/s41557-018-0027-6
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