Self-assembly of clewlike ZnO superstructures in the presence of copolymer

Clewlike ZnO superstructures were synthesized using a copolymer-controlled self-assembly method in the presence of urea. The structural properties were investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and selected-area electron diffraction techniques. It was observed that the concentrations of the copolymer and urea are the key parameters determining the superstructure morphology. Experimental data also showed that the copolymer has played a dual function in the self-assembly process; namely, one is to control the oriented attachment of the nanoparticles, and the other is to stabilize the superstructures. Room-temperature photoluminescence data showed interesting optical properties of the ZnO superstructures.