Development of Strutural Method for the Study of Two Dimensional Molecular Arrangement of Monolayers on the Surfaces of Water and Baseplate

在1987财政年度，准备了用于表面衍射研究的X射线测角仪和truph。在1988财年，我们证实了使用这种truph在水面上形成了高质量的朗缪尔膜。我们进行了表面衍射实验，从一个单层膜的表面上的水使用此truph和同步辐射光束的多极扭摆器光束线在光子工厂，国家高能物理实验室。对于花生酸盐样品，我们甚至在中等表面张力区也观察到衍射峰，据信在该区域形成了二维体系的液相。随着表面张力的增加，该峰从低角度向高角度移动，反映了分子间距离的缩短。在据信形成固相的较高张力区域，衍射峰变得尖锐，但角度位置保持恒定。在镉离子存在的情况下，即使在表面张力很低的区域，也能观察到二维体系的衍射峰，该峰的角位置保持不变，但峰强度随表面张力的增加而增加。这可以解释为，即使在非常低的表面张力下也形成岛状结构，并且这些结构随着表面张力的增加而增长。如上所述，我们成功地利用表面衍射技术提取了关于水表面上的单层膜的二维结构的有用信息。

In fiscal year of 1987, an X-ray gonimeter and a truph for surface diffraction study were prepared. In fiscal 1988 year, we confirmed that a good quality Langmuir film is formed on the surface of water using this truph. We performed a surface diffraction experiment from a monolayer film on the surface of water using this truph and synchrotron radiation beam available on a multipole wiggler beamline at the Photon factory, National Laboratory for High Energy Physics. For the case of arachidate specimen we observed a diffraction peak even at medium surface tension region where it is believed that liquid phase of the two dimensional system is formed. This peak moved from low angle to higher angle as the surface tension is increased reflecting that the intermolecular distance is shortened. At higher tension region where it is believed that a solid phase is formed, the diffraction peak became sharper,but the angle position stayed constant. in the presence of cadmium ion in the water, a diffraction peak was observed even at very low surface tension region where it is believed that a gas phase of the two dimensional system is formed.The angle position of this peak stayed constant, while the peak intensity increase as the surface tension was increased. This may be interpreted that island like structures are formed even at very low surface tension, and these structures grows as the surface tension is increased.As described above, we were successful in extracting useful information on the two dimensional structure of monolayer films on the surface of water using a surface diffraction technique.