Preparation of nanostructured materials via plasma induced by laser in liquid under pressures from atmospheric to over-critical

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560882
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Material processing/treatments
• Research Institution: Tokai University (2013-2014); Osaka University (2012)
• Principal Investigator: KULINICH Sergei 東海大学, 創造科学技術研究機構, 准教授 (00623092)
• Co-Investigator(Kenkyū-buntansha): ITO Tsuyohito 大阪大学, 工学研究科, 准教授 (70452472)
• Co-Investigator(Renkei-kenkyūsha): SHIMIZU Yoshiki 国立研究開発法人, 産業技術総合研究所, ナノ材料研究部門, 主任研究員 (20371049)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: Laser ablation / Pressurized liquid / Nanomaterials / ZnO / Photoluminescence / Supercritical water / In-situ shadowgraphy / Sn

Outline of Final Research Achievements

The effect of high pressure and medium composition on the properties and morphologies of nanoparticles (NPs) prepared via the laser ablation in liquid (LAL) technique was studied. We mainly focused on ZnO NPs (prepared in water-ethanol mixtures at different pressures) and on ablation of Sn target in pressurized CO2.In the first system, photoluminescence was measured and analyzed to reveal how different defects in ZnO NPs are governed by both medium chemistry and pressure. In the second system, in-situ shadowgraphy was used to study the behavior of the ablated zone over time, as it first emerged, then developed as a bubble-like structure (BLS), and finally collapsed. The BLS lifetime was shown to be pressure-dependent, being the longest near the density fluctuation ridge of the medium.
The obtained results clearly indicate that both medium chemistry and pressure can be efficiently used to tune the morphology and properties of nanostructures produced via the LAL technique.

Free Research Field

Material science, Applied physics