Synthesis And Applications Of Organic/Inorganic Hybrid Nanoparticles

Amphiphilic block copolymers not only show a rich phase behavior but also present the properties of self-assembly in solution, while inorganic nanoparticles display unique optical, electrical, magnetic, and catalytic properties. If these two components are combined together, the hybrid nanoparticles consisting of block copolymer and inorganic nanocrystals will highly probably present more complex structures and properties than single component. The hybrid structures could not only endow inorganic nanoparticles with stability, processability, biocompatibility, and environmental responsibility (temperature, pH, ect.), but also retain unique physical and chemical properties of nanocrystals. The self-assembly of supramolecular chemistry of composite system fabricated from polymers and inorganic nanoparticles, therefore, have attracted more and more concern. The dissertation includes the following two parts:1. In this section, we synthesized well-defined amphiphilic block copolymers incorporated with a single C60 moiety at the diblock junction point, poly(ethylene oxide)(-C60)-b-polystyrene (PEO45(-C60)-b-PS380), via a combination of atom transfer radical polymerization (ATRP) and [3+2] cycloaddition between reactive azide moiety and C60. Fullerene-containing hybrid vesicles were facilely fabricated for the first time via the self-assembly of PEO45(-C60)-b-PS380 in aqueous solution using 1,4-dioxane as a cosolvent. The current example argues well for the tunable spatial arrangement of desired moieties, such as fullerene or other functional nanoparticles, by employing block copolymers as self-organizing templates.2. We synthesized two types of well-defined biocompatible amphiphilic block poly(ε-caprolactone)-b-poly(solketal methacrylate) (PCL-b-PGMA) and poly(ε-caprolactone)-b-poly(poly(ethylene glycol) methyl ether methacrylate-co-3-azidopropyl methacrylate) (PCL-b-P(OEGMA-co-AzPMA)) via a combination of ring-opening polymerization (ROP) and ATRP. Finally, clcik reaction of azide moieties on the hydrophilic segment with propargyl-folate afforded poly(ε-caprolactone)-b-poly(poly(ethylene glycol) methyl ether methacrylate-co-3-folatepropyl methacrylate) (PCL-b-P(OEGMA-co-FolPMA)). The hybrid micelles with dozens of 4 nm superparamagnetic iron oxide (SPIO) embeded on the shell were successfully prepared by adding aqueous solution of CTAB-stablized SPIO into the micellar solution comicellized from amphiphilic diblock copolymer PCL-b-PGMA and PCL-b-P(OEGMA-co-FolPMA). Laser light scattering (LLS), Atomic Force Microscope (AFM), and high resolution transmission electron microscopy (HRTEM) were employed to characterize the morphologies of hybrid micelles. Moreover, we explored the applications of hybrid micelles in T2-weighted magnetic resonance imaging (MRI) and controlled release of anticancer drug.