A one‐step facile synthesis of submicrometer‐sized hollow silver spheres (see Figure) has been achieved in aqueous solutions by using double‐hydrophilic block copolymer (DHBC)‐surfactant complex micelles as removable templates. The unique silver shell structures are candidates for both fundamental research and applications.

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The crystallization of calcium oxalate in aqueous solutions of a double-hydrophilic block copolymer poly(ethyleneglycol)-block-poly(methacrylic acid) (PEG-b-PMAA) has been investigated, focusing on morphological control of the calcium oxalate dihydrate (COD) crystals. It has been shown that with increasing polymer concentration, the morphology of the obtained COD crystals gradually changed from tetragonal bipyramids dominated by the {101} faces to rodlike tetragonal prisms dominated by the {100} faces, which is a morphology adopted by some plant COD crystals but not obtained in vitro previously. The concentration of calcium oxalate and the [Ca2+]/[C2O4 2-] ratio were also found to show considerable effects on the morphology of the obtained COD crystals. Seed growth experiments further demonstrated the drastic effect of the polymer on the COD crystal morphology. This effect was preliminarily discussed in terms of possible structural correlation between the short PMAA chain of the polymer and the COD {100} planes.

Shuttle-like crystalline TiO 2 nanoparticles were synthesized by hydrolysis of titanium tetrabutoxide in the presence of acids in NP-5 (Igepal CO-520)-cyclohexane reverse micelle at room temperature. Pure rutile nanoparticles were obtained at appropriate acid concentrations. The influences of various reaction conditions, such as concentration and type of acid, water content, H 2 O/Ti molar ratio, and reaction time, on the formation, crystal phase, morphology, and size of the TiO 2 particles were investigated.

Novel silver nanowire thin films, which consist of interwoven bundles of single-crystalline silver nanowires about 30−40 nm in diameter, have been successfully synthesized on glass wall by mild chemical reduction in aqueous solutions of poly(methacrylic acid) at room temperature. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and UV−vis absorption spectroscopy have been used to characterize the obtained silver products. It was found that there existed a competition between precipitation of spherical particles, precipitation of individual nanowires, and formation of silver nanowire films. It was revealed that the negatively charged glass surface provided heterogeneous nucleation sites for the growth of bundles of silver nanowires. Appropriate pH values and polymer concentrations were crucial for the growth of dense silver nanowire films on the glass wall. A polymer-mediated heterogeneous nucleation and growth process has been proposed for the formation of the unique metal nanowire thin films.

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The controlled synthesis of silver microcrystals with novel morphologies, such as solid or multiholed single crystalline disks, flowerlike aggregates consisting of platelike petals, and dendritic crystals consisting of wide leaves, was realized by using the polysaccharide dextran as a crystal growth modifier. The effects of dextran nature, dextran concentration, temperature, and solvent on the morphology of the silver crystals were investigated, and the obtained products were characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. While the nonionic dextran showed little effect on the silver crystallization, the anionic dextran sulfate exhibited a significant influence on the morphology of the silver crystals. Silver microdisks with solid or multiholed structures were facilely obtained in water at a high dextran sulfate concentration (100 g L -1 ). With the aid of formamide, silver microdisks with thicknesses as thin as 50 nm can be easily obtained at a relatively low dextran sulfate concentration (10 g L -1 ).

Stable multilayer ultrathin films were constructed by alternate deposition of nitro-diazoresin (NDR) and Ag nanoparticles (Ag-NPs) followed by UV irradiation. The absorbance of the un-irradiated film at 385 and 412 nm, which is the characteristic absorption of –N2+ of NDR and Ag-NPs respectively, increases linearly with the fabrication cycle. This result shows that the layer-by-layer electrostatic deposition of NDR and Ag-NPs is successful and uniform. An atomic force microscopy image of the film with four deposition cycles demonstrates the presence of the close-packed Ag-NPs with the average roughness of 1.5 nm. Furthermore, the stability of the irradiated film toward polar solvents and salty liquids increases significantly, due to the formation of covalent bonds between the layers of the assembled film upon exposure to UV light.