Hydrogen bonded supramolecular polymers in protic solvents: role of multitopicity

We describe the synthesis of macromolecular amphiphiles of various molar masses containing well-defined hydrophobic groups incorporating urea moieties. All compounds have the same proportion of associative hydrophobic groups and solubilising POE chains. However, a strong influence of both the number of associative groups per chain and the polydispersity is demonstrated. In water, where the interactions between stickers are strong, the monomer (bearing a single sticker) self-assembles into filaments, but all other compounds with more than one sticker per chain are insoluble. In methanol, where the interactions between stickers are weaker, neither the monomer nor the monodispersed dimer is assembled, whereas polydispersed chains with an average number of 2 or 3 stickers per chain self-assemble into filaments, leading to macroscopic gelation.