Photo-force controlled molecular systems and materials

我们通过将聚焦的1064 nm激光束的光子压力应用于溶液中的分子和纳米颗粒系统，并从分子的角度分析了它们的捕获和组装动力学，探索了新的现象。新的激光沉积现象被发现和阐明，而新的光谱和图案化的方法，为个别纳米粒子提出。这些结果是新颖的，形成了“光子压力化学”的一个新的研究领域，其主要结果如下.利用聚焦光束在室温下的溶液中制备了聚合物纤维状结构，并将其沉积在基底上。该制备是在流动溶剂中捕获聚合物实现的过饱和条件下进行的.当光束强度大时，可以同时捕获聚合物和溶液表面变形。结果表明，聚合物聚集体留在焦点处，在中等激光功率下聚合物聚集体体积最大，并建立了模型.采用单粒子荧光测量和荧光相关光谱法测量了荧光聚合物纳米球的光俘获动力学，分析了单个纳米球的光俘获如何演变成大的聚集体.激光捕获和光谱的单个纳米粒子和纳米晶体在溶液中被成功地证明为金纳米粒子，J-聚集体，和银纳米宝石与染料。提出了一种结合捕集、加热和聚合的单纳米粒子在溶液中的三维捕集和图案化方法。这种方法将是有用的图案软材料，如聚合物，树枝状聚合物，蛋白质，活细胞，和其他在溶液中。

We have explored new phenomena by applying photon pressure of a focused 1064 nm laser beam to molecular and nanoparticle systems in solution and analyzed their trapping and assembling dynamics from molecular viewpoints. New laser deposition phenomena were found and elucidated, while new spectroscopic and patterning methods for individual nanoparticles were proposed. The results are novel and form a new research area on "photon pressure chemistry", whose main results are listed below.1. Fiber-like structure of polymers in solution at room temperature are prepared by the focused beam and deposited on a substrate. The preparation is made possible under the super-saturated condition realized by trapping polymers in the flowing solvent.2. When the beam is intense, simultaneous trapping of the polymer and deformation of the solution surface is made possible. As a result polymer assembly is left at the focal point, whose volume is largest at the medium laser power, for which a model was presented.3. Optical trapping dynamics of fluorescent polymer nanospheres were measured by single particle fluorescence measurement and fluorescence correlation spectroscopy, and how trapping of individual nanoshperes evolves to a large aggregate was analyzed.4. Laser trapping and spectroscopy of single nanoparticles and nanocrystals in solution was successfully demonstrated for gold nanoparticles, J-aggregates, and silver nanopaticles with dyes.5. A 3-dimensional trapping and patterning method of single nanoparticles in solution was presented by combining trapping, heating, and polymerization. This method will be useful to pattern soft materials such as polymers, dendrimers, proteins, living cells, and others in solution.