Study on the preparation and the self-assembly of poly(propyleneimine)-poly(styrene) nanoparticles

Using 2-chloropropionamide derivative of poly(propyleneimine) dendrimer DAB-dendr-(NH2)(32) (DAB-32-Cl) as the macroinitiator, atom transfer radical polymerization of styrene was successfully carried out in DMF medium. The monodisperse poly(propyleneimine)-polystyrene (dendrimer-PSt) particles with diameters smaller than 100 nm could be prepared. The morphology, size, and size distribution of the dendrimer-PSt particles were characterized by transmission electron microscopy (TEM) and photon correlation spectroscopy (PCS). The effects of reaction temperature, the ratio of St/macroinitiator, and reaction time on the size, and size distribution of the dendrimer-PSt nanoparticles were investigated. In a selective solvent (DMF/H2O), polymers can self-assemble into different aggregate configurations such as regular microsphere and wire-like thread. (c) 2008 Wiley Periodicals, Inc.