標題: Time-Resolved Spectroscopic and Imaging Studies on Laser Ablation of Molecular Systems: From Mechanistic Study to Bio/Nano Applications
作者: Masuhara, Hiroshi
應用化學系
應用化學系分子科學碩博班
Department of Applied Chemistry
Institute of Molecular science
公開日期: 15-Jul-2013
摘要: Studies on laser ablation of polymer films, molecular crystals in solution, protein solution, and culture media containing living cells are summarized and considered. Dynamics and mechanism of laser ablation were systematically studied by utilizing time-resolved spectroscopy and imaging; femtosecond-nanosecond transient absorption and emission spectroscopy, nanosecond shadowgraphy, nanosecond-nanometer interferometry, femtosecond surface light scattering imaging. It was confirmed by integrating both data that primary processes of laser ablation can be well understood in the framework of Jablonski diagram. For nanosecond laser ablation of doped polymers, it was demonstrated that cyclic multiphoton absorption is an efficient photothermal conversion process leading to photothermal ablation. For femtosecond laser ablation of dye films, transient pressure mechanism was proposed indicating photomechanical ablation. As applications of laser ablation, nanoparticle preparation, protein crystallization, and manipulation of living cells are presented. Laser ablation of molecular crystals in poor solvent gives small fragments whose size are in a few tens nm. The fabricated nanocolloids are stable without adding detergents and their size was the smallest as nanoparticles produced by the top-down-method. Multiphoton laser ablation of water generates local impulsive force due to bubble formation, shockwave propagation, and local convection flow. The force triggers molecular and protein crystallization in their supersaturated solutions, whose mechanisms are described and considered. The impulsive force is also very useful for manipulating living cells and its high potential was confirmed by examining cell functions such as division, differentiation, death, and migration. Finally summary and future plan are presented.
URI: http://dx.doi.org/10.1246/bcsj.20130066
http://hdl.handle.net/11536/23483
ISSN: 0009-2673
DOI: 10.1246/bcsj.20130066
期刊: BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
Volume: 86
Issue: 7
起始頁: 755
結束頁: 783
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