The hybrid structures of polystyrene-b-poly（ethylene oxide） （PS-b-PEO） block copolymer and inorganic nanoparticles with good stability and biocompatibility have potential applications in drug delivery and bioimagi...The hybrid structures of polystyrene-b-poly（ethylene oxide） （PS-b-PEO） block copolymer and inorganic nanoparticles with good stability and biocompatibility have potential applications in drug delivery and bioimaging. Spherical co-assemblies of PS120-b-PEO318 and oleylamine-capped CdS quantum dots （QDs） are produced successfully in this work by adding water to a mixed common solvent, such as N,N-dimethylmethanamide （DMF）/chloroform, DMF/tetrahydrofuran （THF）, or DMF/toluene. The energy dispersive X-ray （EDX） spectrum indicates that QDs are located at the interface between the core and shell of the spherical co-assemblies. The co-assembly process during water addition is traced by transmission electron microscopy （TEM） and turbidity measurement. Spherical co-assemblies are formed through budding from bilayers of the block copolymer and QDs. The morphology of the co-assemblies is related to the miscibility of the QD-dispersing solvents with water and the morphology changes from a spherical to a vesicle-like structure with DMF/toluene. Increasing THF content in the mixed solvent causes morphological transitions from spherical co-assemblies to multi-branched cylinders and micelles where QDs are located in the central core. Increasing chloroform content yields vesicle-like structures with protruding rods on the surface. The mechanism of the morphological transitions is also discussed in detail.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21274145)
文摘The hybrid structures of polystyrene-b-poly（ethylene oxide） （PS-b-PEO） block copolymer and inorganic nanoparticles with good stability and biocompatibility have potential applications in drug delivery and bioimaging. Spherical co-assemblies of PS120-b-PEO318 and oleylamine-capped CdS quantum dots （QDs） are produced successfully in this work by adding water to a mixed common solvent, such as N,N-dimethylmethanamide （DMF）/chloroform, DMF/tetrahydrofuran （THF）, or DMF/toluene. The energy dispersive X-ray （EDX） spectrum indicates that QDs are located at the interface between the core and shell of the spherical co-assemblies. The co-assembly process during water addition is traced by transmission electron microscopy （TEM） and turbidity measurement. Spherical co-assemblies are formed through budding from bilayers of the block copolymer and QDs. The morphology of the co-assemblies is related to the miscibility of the QD-dispersing solvents with water and the morphology changes from a spherical to a vesicle-like structure with DMF/toluene. Increasing THF content in the mixed solvent causes morphological transitions from spherical co-assemblies to multi-branched cylinders and micelles where QDs are located in the central core. Increasing chloroform content yields vesicle-like structures with protruding rods on the surface. The mechanism of the morphological transitions is also discussed in detail.
