Cu2O@Cu2O core-shell nanoparticles (NPs) were prepared by using solution phase strategy. It was found that Cu2O@Cu2O NPs were easily converted to Cu2O@Cu NPs with the help of polyvinylpyrrolidine (PVP) and excessive a...Cu2O@Cu2O core-shell nanoparticles (NPs) were prepared by using solution phase strategy. It was found that Cu2O@Cu2O NPs were easily converted to Cu2O@Cu NPs with the help of polyvinylpyrrolidine (PVP) and excessive ascorbic acid (AA) in air at room temperature, which was an interesting phenomenon. The features of the two kinds of NPs were characterized by XRD, TEM and extinction spectra. Cu2O@Cu NPs with different shell thicknesses showed wide tunable optical properties for the localized surface plasmon (LSP) in metallic Cu. But Cu2O@Cu2O NPs did not indicate this feature. FTIR results reveal that Cu+ ions on the surface of Cu2O shell coordinate with N and O atoms in PVP and are further reduced to metallic Cu by excessive AA and then form a nucleation site on the surface of Cu2O nanocrystalline. PVP binds onto different sites to proceed with the reduction utill all the Cu sources in Cu2O shell are completely assumed.展开更多
The polymer on modulating the crystal's habit is an evolving research in pharmaceutical crystallization.This study demonstrates the crystal habit modification of chlorzoxazone(CHZ)by heterogeneous crystallization(...The polymer on modulating the crystal's habit is an evolving research in pharmaceutical crystallization.This study demonstrates the crystal habit modification of chlorzoxazone(CHZ)by heterogeneous crystallization(HC)in the binary solvent acetonitrile-ethanol(A-E(1:1))in the presence of polyvinylpyrrolidine(PVP)at concentrations of 0.50,0.75,and 1.00 wt%.The A-E(1:1)and PVP in HC experiments influenced to change the shape of crystals from needle to plate shape and reduced the crystal size producing a lower aspect ratio(in the range of 1.5-2.3).In the presence of PVP,the CHZ size distribution is 65-78μm which tends to enhance the powder flow-ability of CHZ crystals and as the PVP concentration increases,the nucleation rate decreases.The solubility of size-reduced CHZ crystals at different pH is found to be improved by 1.2-1.4 times.Hence,HC is deemed effective in modifying the physicochemical attributes of CHZ.展开更多
基金Projects(41172110,61107090)supported by the National Natural Science Foundation of China
文摘Cu2O@Cu2O core-shell nanoparticles (NPs) were prepared by using solution phase strategy. It was found that Cu2O@Cu2O NPs were easily converted to Cu2O@Cu NPs with the help of polyvinylpyrrolidine (PVP) and excessive ascorbic acid (AA) in air at room temperature, which was an interesting phenomenon. The features of the two kinds of NPs were characterized by XRD, TEM and extinction spectra. Cu2O@Cu NPs with different shell thicknesses showed wide tunable optical properties for the localized surface plasmon (LSP) in metallic Cu. But Cu2O@Cu2O NPs did not indicate this feature. FTIR results reveal that Cu+ ions on the surface of Cu2O shell coordinate with N and O atoms in PVP and are further reduced to metallic Cu by excessive AA and then form a nucleation site on the surface of Cu2O nanocrystalline. PVP binds onto different sites to proceed with the reduction utill all the Cu sources in Cu2O shell are completely assumed.
文摘The polymer on modulating the crystal's habit is an evolving research in pharmaceutical crystallization.This study demonstrates the crystal habit modification of chlorzoxazone(CHZ)by heterogeneous crystallization(HC)in the binary solvent acetonitrile-ethanol(A-E(1:1))in the presence of polyvinylpyrrolidine(PVP)at concentrations of 0.50,0.75,and 1.00 wt%.The A-E(1:1)and PVP in HC experiments influenced to change the shape of crystals from needle to plate shape and reduced the crystal size producing a lower aspect ratio(in the range of 1.5-2.3).In the presence of PVP,the CHZ size distribution is 65-78μm which tends to enhance the powder flow-ability of CHZ crystals and as the PVP concentration increases,the nucleation rate decreases.The solubility of size-reduced CHZ crystals at different pH is found to be improved by 1.2-1.4 times.Hence,HC is deemed effective in modifying the physicochemical attributes of CHZ.
