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，研制了一台X射线测力仪和一台用于表面衍射研究的TRUP。在1988财政年度，我们证实了使用该Trupp在水面上形成了质量良好的朗缪尔膜。我们在国家高能物理实验室光子工厂的多极摇摆器光束线上，用这种特鲁普和同步辐射光束对水面上的单层膜进行了表面衍射实验。对于花生酸盐样品，即使在中等表面张力区也观察到衍射峰，认为在那里形成了二维体系的液相。随着表面张力的增加，这一峰由小角度向高角度移动，反映了分子间距离的缩短。在认为形成固相的高张力区，衍射峰变得更尖锐，但角位置保持不变。在水中有镉离子存在时，即使在表面张力很低的区域也观察到衍射峰，认为在那里形成了二维体系的气相，该衍射峰的角度位置保持不变，但峰强度随着表面张力的增加而增加。这可以解释为即使在很低的表面张力下也会形成岛状结构，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水表面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.