Study On The Construction And Self-assembly Of Amphiphilic Supramolecular Polymers That Based On CB[8]

Purpose:Study on the construction and properties of novel amphiphilic supramolecular polymers(ASPs).Methods:We designed and synthesized a series of rigid building blocks as supramolecular monomers,which bear a hydrophobic alkyl segment and a hydrophilic oligoglycol on both sides.The one having the best water solubility was used to co-assembly with cucurbit[8]uril(CB[8])in water,which resulted in the formation of an ASP with rigid linear main chain and symmetrically distributed hydrophilic/hydrophobic branches,driven by CB[8]-encapsulation-enhanced aromatic stacking interactions.Results:The as-formed ASP was characterized with ~1H NMR titration,Job's plot,~1H NMR COSY,2D ~1H NOESY,2D ~1H DOSY,DLS,UV-visible and fluorescence spectroscopies.And the morphology of the as-prepared supramolecular polymers was also studied by TEM and SEM.The experimental results reveled that the ASP could further self-assemble into well-defined higher level architectures depending on its concentration,for example,nanotubes at low concentration and two-dimensional film-like structures at high concentration.Moreover,pH-responsive behavior of the ASP was also observed.De-polymerization occurs under acidic condition and the ASP can be recovered by addition of base.Such transformation can be repeated many cycles by alternately adding acid and base,displaying very good reversibility.Conclusion:A novel amphiphilic supramolecular polymer with pH-responsive was successfully constructed.This study provides a basis for the development of stimuli-responsive nanomaterials from amphiphilic supramolecular polymers.