Synthesis of Nonionic Dendrimer-like Star Block Copolymers Based on PCL and PEG as Stabilizer for Gold Nanoparticles

Synthesis of Nonionic Dendrimer-like Star Block Copolymers Based on PCL and PEG as Stabilizer for Gold Nanoparticles

Here we report the preparation of nanocomposites from gold nanoparticles (AuNPs) coated with synthesized nonionic amphiphilic dendrimer-like star block copolymers (DLSPs).
At first, the 9G3(Poly(ethyleneglycol) (PEG))36 was synthesized in two main steps. A second-generation dendrimer-like star poly (ε-caprolactone) (PCL) was obtained through ring-opening polymerization (ROP) of ε-caprolactone (CL) from asymmetric 9-hydroxylated core. Subsequently, the amphiphilic G3-DLSPs was prepared via the coupling reaction of 36-end groups quantitatively with carboxyl-terminated MPEG-OH. The hydroxyl protected 2-bis (hydroxymethyl) propionic acid (BHMPA) as a conventional AB2- type branching agent was used. The self-assembly behavior of the obtained amphiphilic DLSPs was studied using 1H NMR and fluorescence spectroscopy (to determin critical micelle concentration (CMC) values). The small values of CMCs were suggesting the convenient stability of the DLSPs assemblies in aqueous media.