Generating Silicon Nanofiber Clusters from Grinding Sludge by Millisecond Pulsed Laser Irradiation.

Silicon nanofiber clusters were successfully generated by the irradiation of millisecond pulsed laser light on silicon sludge disposed from wafer back-grinding processes. It was found that the size, intensity, and growing speed of the laser-induced plume varied with the gas pressure, while the size and morphology of the nanofibers were dependent on the laser pulse duration. The generated nanofibers were mainly amorphous with crystalline nanoparticles on their tips. The crystallinity and oxidation degree of the nanofibers depended on the preheating conditions of the silicon sludge. This study demonstrated the possibility of changing silicon waste into functional nanomaterials, which are possibly useful for fabricating high-performance lithium-ion battery electrodes.

Adsorption of polyaromatic hydrocarbons on single wall carbon nanotubes of different functionalities and diameters.

Adsorption from toluene solution of phenanthrene and tetracene on single wall carbon nanotubes (SWCNT) is measured. Comparison of adsorbents such as laser ablation and HipCO samples reveals multiple factors influencing the adsorption mechanism. Acid functionalized carbon nanotubes have shown markedly increased adsorbability for the polyaromatic molecules. The linear tetracene molecule's adsorption is more promoted on nanotubes with increasing diameter, but also additionally with presence of the carboxylic groups. The adsorption mechanisms on carboxylic sites and on the bold, non-functionalized large-diameter nanotubes are suggested and supported by detailed characterization of the SWCNTs applied.

Effect of nanoscale curvature of single-walled carbon nanotubes on adsorption of polycyclic aromatic hydrocarbons.

Liquid-phase adsorption of tetracene and phenanthrene on a single-walled carbon nanotube (SWCNT) was examined. Tetracene adsorption was more than six times greater than that of phenanthrene. X-ray photoelectron spectroscopic examination clearly showed that tetracene and phenanthrene molecules efficiently coated the SWCNT external surfaces. The remarkable difference between the adsorption amounts of tetracene and phenanthrene was caused by the nanoscale curvature effect of the tube surface, resulting in a difference in the amount of contact between the molecule and the tube surface. The adsorption of tetracene and phenanthrene caused a significant higher frequency shift in the radial breathing mode (RBM) of the Raman band of the SWCNT, indicating an intensive pi-pi interaction between these polycyclic aromatic hydrocarbons and the external SWCNT surface.