Metallo-supramolecular block copolymers : from synthesis to smart nanomaterials
Supramolecular copolymers have become of increasing interest in recent years for the search of new materials with tunable properties. In particular, metallo-supramolecular block copolymers have seen important progresses since the last ?ve years.
In this thesis, a library of metallo-supramolecular amphiphilic block copolymers containing a hydrophilic block, linked to a hydrophobic block, through a metal-ligand complex has been investigated. The micelles formed in water from these copolymers were characterized by AFM and TEM and exhibited a di?erent behavior compared to their covalent counterpart.
Furthermore, a novel strategy to control the formation of amphiphilic brushes from metallo-supramolecular block copolymers has been developed. Starting from a heteroleptic block copolymer, the initial low molecular weight counterions were exchanged for polymeric ones, leading to the formation of complex architectures.
Another part of this thesis is dedicated to the use of metal-ligand interactions located at the extremity of micelles. Since ligands are located at the extremity of the coronal chains, they are available for complexation with metal ions. The e?ect of the addition of various metal ions to this system was studied in the dilute regime by dynamic light scattering, and di?erent situations have been observed depending on the metal-to-ligand ratio and to the nature of the metal ions.
In more concentrated solutions, a second hierarchical level is reached leading to the formation of a micellar gel, due to the formation of intermicellar bridges. Rheological measurements revealed that the characteristic behavior of those gels critically depends on the added metal ions.
Finally, the self-assembly of a metallo-supramolecular block copolymer in thin ?lms was investigated. Due to the presence of the charged complex at the junction of the two blocks, this copolymer could be considered as a triblock with a highly immiscible block that e?ects the orientation of the cylindrical microdomains and the lateral ordering.
School:Université catholique de Louvain
Source Type:Master's Thesis
Keywords:self assembly gel micelle supramolecular block copolymer polymer
Date of Publication:07/08/2008