Studies On Soft Cluster Template In The Synthesis Of Cu-containing Nano/Submicro Particles

In this paper, the interaction between copper ions and sodium dodecyl sulfate(SDS)- polyvinylpyrrolidone(PVP) soft cluster was studied by means of surface tension method and steady-state fluorescence quenching technique. Surface tension results show that the soft cluster formed spontaneously by PVP and the bound micelle of SDS in cases with or without copper ions addition. Theγ-lgc curves of CuSO4-SDS-PVP systems still hold two critical concentrations: the first critical concentration (c1) and the second critical concentration (c2). The increase of copper ions'concentration favors the formation of bound-micelle, and making surface tension decrease further. In the meantime, c1 decreases while c2 increases with ever-increasing level of copper ions, therefore, the clusterization boundary of SDS-PVP cluster extends. The saturation capacity of clusterization (Γ∞) and the specific saturation capacity of clusterization ([Γ∞]) increase with the addition of copper ions. According to the results of steady-state fluorescence quenching technique, Nb increases with the increase of the concentration of SDS, while on the contrary decrease with the addition of copper ions.Hollow cuprous oxide (Cu2O) submicrospheres were reduced from CuSO4 by N2H4·H2O simply in the soft template of SDS-PVP cluster. XRD pattern shows that the synthesized hollow submicrospheres are pure Cu2O crystals that are composed of Cu2O nanoparticles with diameters of about 11～22 nm and main diffraction planes of (111). SEM and TEM images demonstrate the hollow nature of the hollow Cu2O submicrospheres with average diameters ranging form 420 to 550 nm. The two-ply soft template of PVP-SDS cluster provides the secondary self-assembly function, which explains the firstly self-assembly of Cu2O nanoparticles in the first microreactor of SDS bound micelle and the secondary self-assembly of hollow Cu2O submicrospheres by virtue of the secondary bridged template of PVP. The experimental results indicate that in SDS-PVP compound systems, the hollow Cu2O submicrospheres can't be synthesized until the main existence of SDS-PVP clusters, and the particle size, wall thickness and shape of hollow Cu2O submicrospheres can be controlled by adjusting of cSDS.Copper nanoparticles were also reduced from CuSO4 by N2H4·H2O simply in the soft template of SDS-PVP cluster. TEM and XRD results show the average diameter of copper nanoparticles with fcc structure is 20±3 nm. Combined with UV-Vis results, it shows that only the formation of SDS-PVP clusters can the copper nanoparticles be received, which with well-dispersion, even size and accordant shape.