Photo-responsive disassembly of supramolecular polymer bottlebrushes in water

We report the 5-step synthesis and self-assembly of an azobenzene-bisurea sticker flanked by two alkyl spacers and poly(ethylene oxide) arms. In the trans-azobenzene configuration, long nano-cylinders can be obtained by first molecularly dissolving the polymer in DMSO, followed by the slow addition of water. The addition of water triggers 1D self-assembly through a combination of strong, cooperative H-bonding between urea motifs and hydrophobic effects. UV-light irradiation triggers the photo-isomerization of azobenzene units into their non-planar cis configuration, rapidly and irreversibly disrupting the photo-responsive assemblies.