Nanofluid Generation Using Multi-Beam Laser Ablation Technique

Multi-beam laser ablation in liquid was used to synthesize nanofluids of silver, Zinc, and aluminum in liquids. In our experiments, two single-mode, Q-switched Nd-Yag lasers operating at 1064 nm, pulse duration of 5.5 ns and 10 Hz rep rate were used. Our results have shown that both laser intensities and multi-beam ablation can increase the ablation rate and promote reduction of the particle sizes and particle size distribution. For silver, we have generated various samples of nanofluids with particles of sizes mainly in the range of 20 to 30 nm. These samples were stable for several months without the need of using dispersants or surfactants. However, for aluminum, the generated fluids were not stable and significant amount of solid precipitates were observed in the stock solutions. The size distribution was from about 5 nm to 300 nm indicating that the particle agglomerated and large distribution in sizes. Typical results from TEM analysis indicated that, for silver-water nanofluids, Ag nanoparticles were fcc single crystals. For aluminum, the particles had different shapes and sizes. These shapes were triangular, rectangular, and fibrous.