A semi-continuous process for the synthesis of fullerenes is described. This novel process incorporated a carbon powder feed system in combination with a continuous-wave CO2 laser irradiation source. The carbon powder contained no fullerenes but did contain graphite crystals and amorphous carbons of selected particle sizes (5, 10, or 20 μm), and selected irregular or spherical particle shapes. The method was successfully used to deposit C60 and C70 powders and films continuously. Laser irradiation of the carbon powder produced an observable laser plume. The experimental results and mechanism for the process are discussed.
Nanometer-sized particles of silicon and titanium dioxide were generated by Nd:YAG laser ablation of solid substrates in a low pressure atmosphere. A low-pressure differential mobility analyzer (LP-DMA) was used to control the size of generated particles. The LP-DMA and a transmission electron microscopy (TEM) were used to measure the change in size distribution and morphology of nanoparticles with laser power and pressure. Finally, we succeeded to synthesize the almost spherical nanoparticles of 2-50 nm in diameter.