title: Efficient size control of copper nanoparticles generated in irradiated aqueous solutions of star-shaped polyelectrolyte containers.
abstract: The formation of copper nanoparticles (Cu-NPs) in irradiated aqueous solutions of star-shaped poly(acrylic acid) (PAA) were studied at two pH values. Transmission electron microscopy (TEM) demonstrates that the star-shaped macromolecules loaded with Cu(2+) ions can act as individual nanosized containers providing a perfect control over the size and size distribution of Cu-NPs. Electron paramagnetic resonance (EPR) and optical spectroscopy show a transformation of mechanisms controlling the reduction of Cu(2+) ions and the further formation of Cu-NPs. At pH 2.9, Cu-NPs are formed from the aquacomplexes of Cu(2+) ions through homogeneous nucleation. At pH 4.3, the formation of Cu-NPs occurs inside macromolecular containers loaded with Cu(2+) ions, which are bound to carboxylic groups of the polyelectrolyte. In the latter case, Cu-NPs apparently ripen from preformed hydrated Cu2O seeds, which are thought to result from the ultrasmall (Cu(2+))m(OH(-))k(COO(-))n species, thus implying a heterogeneous nucleation.
authors: Department of Chemistry, M.V. Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia. aazezin@yandex.ru pergush@genebee.msu.ru.
authors: Alexey A
authors: AA
authors: Zezin
authors: Vladimir I
authors: VI
authors: Feldman
authors: Sergei S
authors: SS
authors: Abramchuk
authors: Gurgen V
authors: GV
authors: Danelyan
authors: Victor V
authors: VV
authors: Dyo
authors: Felix A
authors: FA
authors: Plamper
authors: Axel H E
authors: AH
authors: Müller
authors: Dmitry V
authors: DV
authors: Pergushov
mesh_terms: D003300:Copper / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D012996:Solutions; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D004573:Electrolytes; D011108:Polymers; D012996:Solutions; D014867:Water; D003300:Copper