Tuning block copolymer micelles by metal–ligand interactions

Structure of Metallo‐Supramolecular Micellar Gels

“…In this case, mono -complexes are formed, resulting likely in a partial collapse of the coronal chains bearing those mono -complexes due to the reduced solubility of the latter. Our group has previously reported a similar behavior on PS 47 -b -PtBA 55 -tpy block copolymer micelles in the dilute regime using DLS as characterization tool, [ 23 ] giving additional credit to the results obtained here by SANS. We also note that the hard-sphere interaction distance increases by about 4% in the presence of Zn(II).…”

“…[23][24][25] This copolymer was dissolved in deuterated ethanol, a selective solvent for the PtBA block and a nonsolvent of the PS block. The characteristic features of the resulting micellar solutions in the dilute regime were fi rst investigated by DLS at a concentration of 0.05 g L − 1 .…”

“…[ 21 , 22 ] In this context, we have recently described an original method to trigger the hierarchical self-assembly of block copolymers using metal-ligand interactions. [23][24][25] Firstly, a polystyrene-block -poly( tert -butylacrylate) diblock copolymer bearing a terpyridine moiety at the chain end (PS-b -PtBA-tpy) was dissolved in ethanol, a selective solvent of the PtBA block, to yield micelles composed of a PS core and PtBA coronal chains bearing a terpyridine ligand at their extremity. The second level was then triggered by addition of metal ions resulting in attractive interactions leading to fl ower-like micelles in dilute solutions, [ 23 ] and micellar gels in the concentrated regime.…”

“…[23][24][25] Firstly, a polystyrene-block -poly( tert -butylacrylate) diblock copolymer bearing a terpyridine moiety at the chain end (PS-b -PtBA-tpy) was dissolved in ethanol, a selective solvent of the PtBA block, to yield micelles composed of a PS core and PtBA coronal chains bearing a terpyridine ligand at their extremity. The second level was then triggered by addition of metal ions resulting in attractive interactions leading to fl ower-like micelles in dilute solutions, [ 23 ] and micellar gels in the concentrated regime. [ 24 , 25 ] Such attractive interactions are somewhat similar to those found in other associating systems such as telechelic polymers bearing hydrophobic stickers at the chain ends.…”

“…[ 25 ] Interestingly, the possibility to break those metal-ligand complexes holding the micelles together was achieved either by addition of competing ligands or, in a reversible way, by mechanical stresses, leading to materials exhibiting self-healing properties. [ 24 ] Until now, light scattering was used to determine the typical sizes of those micelles in the dilute regime, [ 23 ] while rheology enabled us to probe the mechanical properties of the micellar gels obtained in the concentrated regime. [ 24 , 25 ] However, no detail is yet available about either the inner structure of the micelles or about their organization in the gel state.…”