The work presented in this manuscript describes the design and synthesis of dendritic core-shell architectures, the different self-organized states of those polymers (lyotropic phases, gels, liquid crystals) and finally the incorporation of gold nanoparticles inside such systems.
Our ambition was to design core-shell structures based on dendritic cores using covalent or non-covalent grafting. Different types of cores were used in this project: polyamidoamide hyperbranched polymers (HYPAM), polyamidoamide dendrimers (PAMAM) and polylysine dendrigraft (DGL). These cores were functionalized with thermoresponsive poly(N-isopropylacrylamide) by amide coupling, with sodium dodecyl sulfate surfactant by ionic interactions, or with ionic block copolymers also by ionic interactions. The core-shell polymers self-assemble into aggregates in aqueous solution, gels or liquid crystals depending on their architectures and their environment. The different phases formed by these structures were used to in situ synthesize gold nanoparticles (Au NPs) as well as to stabilize preformed Au NPs. The change in these phases induced by the incorporation of nanoparticles is presented as well as the original properties of the hybrid systems (mechanical, liquid crystal character, stability ...). In particular, the synthesis of Au NPs in gel networks leads to the formation of hydrogel hybrids where the nanoparticles act as crosslinking points. Furthermore, the template effect of these systems on the size and shape of the in situ formed nanoparticles was studied. The size of AuNPs was governed by the nature of the self-assembled phase related to the structure of the hyperbranched polymer. |
The work presented in this manuscript describes the design and synthesis of dendritic core-shell architectures, the different self-organized states of those polymers (lyotropic phases, gels, liquid crystals) and finally the incorporation of gold nanoparticles inside such systems.
Our ambition was to design core-shell structures based on dendritic cores using covalent or non-covalent grafting. Different types of cores were used in this project: polyamidoamide hyperbranched polymers (HYPAM), polyamidoamide dendrimers (PAMAM) and polylysine dendrigraft (DGL). These cores were functionalized with thermoresponsive poly(N-isopropylacrylamide) by amide coupling, with sodium dodecyl sulfate surfactant by ionic interactions, or with ionic block copolymers also by ionic interactions. The core-shell polymers self-assemble into aggregates in aqueous solution, gels or liquid crystals depending on their architectures and their environment. The different phases formed by these structures were used to in situ synthesize gold nanoparticles (Au NPs) as well as to stabilize preformed Au NPs. The change in these phases induced by the incorporation of nanoparticles is presented as well as the original properties of the hybrid systems (mechanical, liquid crystal character, stability ...). In particular, the synthesis of Au NPs in gel networks leads to the formation of hydrogel hybrids where the nanoparticles act as crosslinking points. Furthermore, the template effect of these systems on the size and shape of the in situ formed nanoparticles was studied. The size of AuNPs was governed by the nature of the self-assembled phase related to the structure of the hyperbranched polymer. |