In: CHIMIA International Journal for Chemistry, 2019, vol. 73, no. 1, p. 7–11
While coupling mechanical and chemical processes is widespread in living organisms, the idea to harness the mechanically induced dissociation of weak covalent and non- covalent bonds to create artificial materials that respond to mechanical stimulation has only recently gained attention. Here we summarize our activities that mainly revolve around the exploitation of non-covalent interactions...
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In: Soft Matter, 2017, vol. 13, no. 22, p. 4017-4023
While azo compounds are widely employed as radical initiators, they have rarely been used as stimuli-responsive motifs in macromolecular constructs. In this study, an azo-based cross-linker was prepared and reacted with poly(vinyl alcohol) to afford a series of stimuli-responsive organogels. Irradiation of these materials with UV light causes de-cross-linking and triggers a solid-to-liquid phase...
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In: Journal of the American Chemical Society, 2017, p. 4302-4305
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In: Chemical Communications, 2016, vol. 52, p. 5694–5697
The first fluorescent cyclophane with mechano- and thermoresponsive solid-state fluorescence characteristics is reported. The new cyclophane comprises two 9,10-bis(phenylethynyl)anthracene moieties that are bridged by tetraethylene glycol spacers. The stimuli-responsiveness is based on molecular assembly changes.
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In: Macromolecules, 2016, vol. 49, p. 2917–2927
Molecules comprising aliphatic azo moieties are widely used as radical polymerization initiators, but only a few studies have explored their usefulness as stimuli-responsive motifs in macromolecular constructs. The controlled degradation of azo-containing polymers has indeed remained largely unexplored. Here we present the syntheses of linear azo-containing polyamides and polyurethanes and...
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In: RSC Advances, 2014, vol. 4, p. 53967-53974
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In: RSC Advances, 2014, vol. 4, p. 53967-53974
Many hydrocarbon polymers containing heteroatom defects in the main chain have been investigated as degradable polyethylene-like materials, including aliphatic polyesters. Here, acyclic diene metathesis (ADMET) polymerization was used for the synthesis of aliphatic poly(sulfonate ester)s. The requisite sulfonate ester containing α,ω-diene monomers with varying numbers of methylene groups...
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In: Macromolecules, 2016, vol. 49, no. 5, p. 1630–1636
The ultrasound-induced cleavage of macromolecules has become a routine experiment in the emerging field of polymer mechanochemistry. To date, it has not been conclusively proven whether the molecular weight of a polymer or its contour length is the determining factor for chain scission upon ultrasonication. Here we report comparative experiments that confirm unequivocally that the contour length...
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In: Chemistry - A European Journal, 2016, vol. 22, no. 13, p. 4374–4378
Multiresponsive materials that display predefined photoluminescence color changes upon exposure to different stimuli are attractive candidates for advanced sensing schemes. Herein, we report a cyano-substituted oligo(p-phenylene vinylene) (cyano-OPV) derivative that forms five different solvent-free solid-state molecular assemblies, luminescence properties of which change upon thermal and...
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In: ACS Appl. Mater. Interfaces, 2015, vol. 7, no. 39, p. 21828–21834
The visualization of polymer deformation using microcapsules filled with charge- transfer complex precursors is reported. Poly(urea-formaldehyde) microcapsules filled with toluene and either hexamethylbenzene as donor or chloranil as acceptor were prepared by in situ polymerization of an oil-in-water emulsion. The resulting microcapsules were incorporated in a poly(dimethylsiloxane) matrix by...
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