Micron-sized presolar carbon-spheres condensed before the origin of our solar system, in the atmosphere of asymptotic-giant-branch stars from carbon atoms dredged up following nucleosynthesis in the stellar interior, have been extracted by dissolution from primitive carbonaceous chondrite meteorites, identified by noble-gas and major-element isotopic analysis, and available to electron microsco...

Large-scale production of pure carbon spheres, with diameters from 50 nm to 1 lm, has been achieved via direct pyrolysis of a wide range of hydrocarbons, including styrene, toluene, benzene, hexane, cyclohexane and ethene, in the absence of catalyst. Specific systematic studies using styrene as the feedstock indicate that the sizes of the resulting of carbon nanospheres can be controlled quite ...

Electron energy loss spectroscopy in a high-resolution transmission electron microscope has recently been used with success to characterize the electronic properties of closed cage nanometer-size graphitic particles. In the plasmon region, the experimental data reveal interesting size-dependent variations, which are not yet fully understood. The difficulties encountered in the interpretation of...

This manuscript describes the fabrication and manipulation of millimeter-scale spheres fabricated from ionotropic hydrogels that are crosslinked with paramagnetic metal ions (e.g., Ho(3+)). These ionotropic hydrogels experience a force in a magnetic field gradient that correlates with the concentration of the paramagnetic cations crosslinking the polymer. In an externally applied magnetic field...

Gold nanoparticles encapsulated in porous carbon spheres with high surface areas (~800 m(2) g(-1)) have been synthesized by ultrasonic spray pyrolysis (USP). The porous carbon-encapsulated gold nanoparticles exhibit excellent catalytic activity toward the reductions of both hydrophilic and hydrophobic nitroaromatics.

We have established a facile and generalizable "silica-assisted" synthesis for diverse carbon spheres-a category that covers mesoporous carbon nanospheres, hollow mesoporous carbon nanospheres, and yolk-shell mesoporous carbon nanospheres-by using phenolic resols as a polymer precursor, silicate oligomers as an inorganic precursor, and hexadecyl trimethylammoniumchloride as a template. The part...

A carbon sphere-modified glass carbon electrode was prepared by employing cyclohexanol as a solvent to disperse the carbon spheres efficiently. The resulting electrode exhibits excellent sensitivity to cadmium(II), and a detection limit of 10(-10) mol/L has been obtained, which is one order of magnitude lower than those obtained by other electrodes. Along with immunity from interference of othe...

Polyaniline (PANI)/Au composite hollow spheres were successfully synthesized using polystyrene/sulfonated polystyrene core/shell gel particle templates. The PANI shell thickness and the number of Au nanoparticles decorating the PANI could be controlled effectively by adjusting the experimental conditions. The morphology, composition, and optical properties of the resulting products were charact...

Ordered mesoporous carbonaceous spheres with variable structures have been successfully prepared by using phenolic oligomers as a carbon precursor and amphiphilic triblock copolymers as a template via a one-step aerosol-assisted organic-organic self-assembly method.