Photo-force controlled molecular systems and materials

利用聚焦1064nm激光束的光子压力作用于溶液中的分子和纳米粒子体系，探索了新的现象，并从分子的角度分析了它们的捕获和组装动力学。发现并阐明了新的激光沉积现象，同时提出了单个纳米颗粒的新的光谱和图案化方法。结果新颖，形成了“光子压力化学”的一个新的研究领域，其主要成果如下：1。通过聚焦光束在室温溶液中制备纤维状结构的聚合物，并将其沉积在衬底上。通过将聚合物捕获在流动的溶剂中，可以在过饱和条件下进行制备。当光束强度较大时，聚合物的同时捕获和溶液表面的变形成为可能。结果表明，在中等激光功率下，聚合物组装体在焦点处体积最大，并建立了相应的模型。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捕获动力学，并分析了单个纳米球的捕获如何演变成一个大的聚集体。在溶液中对金纳米粒子、j -聚集体和银纳米粒子进行了激光捕获和光谱分析。采用捕集、加热和聚合相结合的方法，提出了一种单纳米粒子在溶液中的三维捕集和图像化方法。该方法可用于聚合物、树突、蛋白质、活细胞等软质材料的图案绘制。

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.