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Hypothesis: Supramolecular polymer bottlebrushes (SPBs) consist in the 1D self-assembly of building blocks composed of a self-assembling core with pendant polymer arms. Kinetic hurdles often hinder their stimuli-responsiveness in solution. Changing the nature of the solvent should alleviate these hurdles by modulating the self-association strength, leading to stimuli-responsive SPBs., Experiments: The SPBs were formed, in various solvents, by hydrogen bond-driven self-assembly of an azobenzene-bisurea decorated with poly(ethylene oxide) polymer arms. The photo-isomerization of the azobenzene unit was studied by UV/visible spectroscopy and proton NMR spectroscopy, whereas the consequences on supramolecular self-assembly were studied by small angle neutron and X-ray scattering., Findings: In water, the assembly was previously shown to be driven by both hydrogen-bonds and strong hydrophobic effects, the latter rendering the system kinetically frozen and the disassembly irreversible. Here we show that in organic solvents such as toluene or chloroform, reversible light-responsive dissociation is achieved. Solvophobic effects in these solvents are expected to be much weaker than in water, which probably allows reversibility of the light-response in the former solvents. The key role of the solvent on the reversibility of the process opens up new perspectives for the design of stimuli-responsive SPBs and their applications in various fields., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Hypothesis: Switchable assemblies relevant for bio-applications may be accessed from water-soluble tetra-ortho-substituted azobenzenes that reversibly self-assemble and form complexes with β-cyclodextrin under visible light., Experiments: Two azobenzenes bearing either four fluorines or two chlorines and two fluorines in the ortho positions were synthesised with short poly(ethylene oxide) tails for water solubility. Photophysical properties were determined by UV-vis and 1 H NMR spectroscopies, complexation with β-cyclodextrin was assessed by 1 H NMR spectroscopy, and self-assembly in water was investigated by static and dynamic light scattering., Findings: Both molecules underwent trans-cis isomerization at 530 nm and cis-trans isomerization at 415 nm, with the cis forms exhibiting thermal half-lives > 300 days at room temperature. Both molecules formed inclusion complexes with β-cyclodextrin in water, with cis-4F-AZO-PEO binding 3-fold stronger than trans, and 2Cl2F-AZO-PEO binding significantly weaker. Self-assembly of pure 2Cl2F-AZO-PEO in water showed an open association process regardless of configuration, while 4F-AZO-PEO showed an open association process for cis (N agg increasing from 30 to 1000) but a closed association process for trans (N agg stable at ∼ 170). Aqueous solutions of 2Cl2F-AZO-PEO showed cloud points close to 45 °C, while the 4F-AZO-PEO isomers presented well-separated cloud points allowing reversible and all-visible transition between clear and turbid states at room temperature., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Hypothesis: Water in water (W/W) emulsions are formed by mixing aqueous solutions of incompatible polymers. It is possible to add a third polymer solution that forms at the right conditions a phase that completely covers the dispersed droplets as a thin layer. Our hypothesis is that by gelling the third phase, W/W emulsions can be stabilized and that microcapsules can be formed that are stable against dilution., Experiments: W/W emulsions were formed by mixing aqueous solutions of poly(ethylene oxide) (PEO) and dextran. Gelatin was added to form the third phase, gelation of which was induced by cooling. The morphology was observed by microscopy, and the rheological properties were investigated., Findings: The compatibility of gelatin and PEO can be fine-tuned by the pH such that a continuous layer of the gelatin phase forms around the droplets of the dextran phase, with a thickness that can be varied. After cooling, the gelatin layer forms a gel and provides stabilization against coalescence. The gelatin microcapsule was found to be stable to dilution. The generality of the method was demonstrated by applying it to another, fully food-grade, W/W emulsion formed by mixing amylopectin and xyloglucan., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Cadmium-based quantum dots (QDs) were easily, quickly and efficiently transferred from an organic medium to water without modification of their surface chemistry by the simple emulsion/solvent evaporation technique using micelles of amphiphilic diblock copolymers based on poly(ethylene oxide) and poly(2-methacryloyloxyethyl acrylate) (PEO-b-PMEA) as hosts. The resulting hybrid micelles were stabilized very rapidly by photo-cross-linking the hydrophobic core around the QDs. The encapsulation and photo-cross-linking process were shown to barely affect the photoluminescence properties. Grafting a short octyl chain at the end of the hydrophobic block enhanced both the colloidal stability of the QDs dispersed in water and prevented the quenching of their fluorescence by copper ions. Grafting a longer hexadecyl chain at the end of the PMEA block decreased the efficiency of the corona cross-linking and led to poorer stabilization and protection., (Copyright © 2016 Elsevier Inc. All rights reserved.)