Temporal and space resolved detection of laser-induced crystallization process

激光诱导结晶过程的时间和空间分辨检测

• 批准号: 16072212
• 负责人: MIYASAKA Hiroshi
• 金额: $ 17.6万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16072212/
• 关键词: Molecular crystal; Photo-switching; Single molecule detection; Mesoscopic systems; レーザー誘起結晶化; 相分離; レーザー多光子顕微鏡; 単一分子計測; 結晶成長; レーザー誘起現象; フェムト秒分光; ナノ秒分光; 結晶核生成; レーザー分光

With a view to elucidating molecular dynamics in the nucleation process of organic crystals in solids, we have studied model systems, pyrene molecules in low temperature glassy matrices of mixture solvent consisting of isopentane and methylcyclohexane. In the series of experiments we demonstrated that irradiating several thousands of nanosecond laser pulses at 355 nm to the model system induced the efficient aggregation of the solute in the solid matrices even at 77 K. During the crystallization induced by successive UV irradiation, an emission peak that could be attributed to the excimer of pyrene increased in intensity with an increase in the shot-number of the UV pulse, while the excimer emission was not detected without laser irradiation. The excimer emission appeared even by single shot irradition of the UV pulse, which indicates that the single shot of the laser pulse enabled pyrene molecules to stick together by translational/rotational diffusion. This can be explained by transient melting of the glassy matrices induced by the laser irradiation. Time-resolved fluorescence measurements from ps to ns region revealed that the solute molecules moved and formed excimer within the time-width of the UV pulse; the excimers were frozen before dissociation because of short duration of the transient melting almost same as that of the UV pulse and longer lifetime of pyrene excimer (〜 100 ns order). This different time-scale between aggregation and dissociation can explain the efficient aggregation of the solute by UV irradiation in this system.

为了阐明有机晶体在固体中成核过程中的分子动力学，我们研究了模型体系，即在异戊烷和甲基环己烷混合溶剂的低温玻璃基质中的芘分子。在一系列的实验中，我们证明了在355nm的波长下，向模型系统照射数千纳秒激光脉冲，即使在77k的温度下，也能诱导固体基质中溶质的有效聚集。在连续紫外照射诱导结晶过程中，随着紫外脉冲发射次数的增加，芘准分子的发射峰强度增加，而在没有激光照射的情况下没有检测到准分子的发射。在单次照射的情况下也出现了准分子发射，说明单次照射的激光脉冲使芘分子通过平移/旋转扩散而粘在一起。这可以用激光照射引起的玻璃基体的瞬态熔化来解释。从ps到ns区域的时间分辨荧光测量表明，溶质分子在紫外脉冲的时间宽度内移动并形成准分子；在解离前将准分子冷冻，因为瞬时熔化时间短，与紫外脉冲几乎相同，而芘准分子的寿命更长（~ 100 ns量级）。这种聚集与解离时间尺度的差异可以解释紫外辐照下溶质的高效聚集。

项目成果

Dynamics and Mechanisms of Multiphoton Gated Photochromic Reaction of Diarylethene Derivatives

二芳基乙烯衍生物多光子门控光致变色反应动力学及机理

• 发表时间: 2004
• 期刊: J. Am. Chem. Soc. 126
• 作者: Masataka Murakami;Hiroshi Miyasaka;Tadashi Okada;Seiya Kobatake;Masahiro Irie
• 通讯作者: Masahiro Irie

Development Femtosecond Near-Infrared Microscope and Higher-Order Multiphoton Imaging

飞秒近红外显微镜和高阶多光子成像的开发

• 发表时间: 2006
• 作者: Hirohisa Matsuda;Syoji Ito;Yutaka Nagasawa;Hiroshi Miyasaka;Tsuyoshi Asahi;Hiroshi Masuhara
• 通讯作者: Hiroshi Masuhara

Quantitative Evaluation of Local Heating at the Focus of Near Infrared Laser Beam under Optical Trapping Condition

光捕获条件下近红外激光束焦点局部加热的定量评估

• 发表时间: 2006
• 作者: Syoji Ito;Takashi Sugiyama;Naoki Toitani;Hiroshi Miyasaka
• 通讯作者: Hiroshi Miyasaka

Laser Manipulation and Ablation of Individual Gold Nanoparticles in Solution for Deposition of nm-sized Gold Fragments onto Substratess

激光操纵和烧蚀溶液中的单个金纳米颗粒，将纳米级金碎片沉积到基材上

• 发表时间: 2004
• 作者: Syoji. Ito;Toshiaki Mizuno;Hiroyuki Yoshikawa;Hiroshi Masuhara
• 通讯作者: Hiroshi Masuhara

“Assembling nano/bio Materials by Utilizing Focused Laser Beams", Nanophotonics ; Integrating Photochemistry, Optics and Nano/Bio Materials Studies, Chapter 26, (2004) Eds., Hiroshi Masuhara and Satoshi Kawata

“利用聚焦激光束组装纳米/生物材料”，纳米光子学；集成光化学、光学和纳米/生物材料研究，第 26 章，(2004) Eds.，Hiroshi Masuhara 和 Satoshi Kawata

• 发表时间: 2004
• 作者: Syoji Ito;Chie Matsubara;Yoichiro Hosokawa;Keiko Ikeda;Hajime Mori;Hiroshi Masuhara
• 通讯作者: Hiroshi Masuhara