Molecular Assembling by Radiation Pressure of Laser Beam

利用聚焦红外激光束的光子压力，在显微镜下研究了溶液中单个微粒的形成过程，并分析了微粒的内部结构。该研究被认为是一种不同于传统光物理和光化学的新型光子压力化学。选择分子内电荷转移分子作为荧光探针，对其光物理和光化学性质进行了详细的研究。合成了与分子内电荷转移分子结合的聚丙烯酰胺聚合物，研究了其对热、pH及相关刺激的动态响应。通过聚焦红外激光束。在光子压力的作用下，聚丙烯酰胺聚集在显微镜的焦点处，形成一个单一的微粒。不时观察其制备过程，并利用皮秒荧光显微镜分析其特有的内部结构。同样，研究了由嵌段共聚物胶束组成的单个微粒，并通过空间分辨和时间分辨荧光分析揭示了单个微粒的局部环境条件和形态。

We have studied formation process of a single microparticle in solution under a microscope by photon pressure of a focused infrared laser beam and analyzed inner structure of the microparticle. This study is regarded as a new chemistry by photon pressure, which is quite different from conventional photophysics and photochemistry.Intramolecular charge transfer molecule was chosen as a fluorescence probe, and its photophysical and photochemical properties were studied in detail. Polyacrylamide polymer bonded with the intramolecular charge transfer molecule was synthesized, and its dynamic responses to thermal, pH, and related stimuli were studied. By focusing the infrared laser beam. the polyacrylamide are gathered at the focal point of the microscope by photon pressure, forming a single microparticle. The preparation process was observed from time to time, and its characteristic inner structure was analyzed by picosecond fluorescence microscopy. Similarly, a single microparticle composed of block copolymer micelles was studied, and local environmental condition and morphology of the single microparticle were revealed by space- and time- resolved fluorescence analysis.