STUDY ON MEASUREMENTS OF CONTACT ANGLES AND LINE TENSION BY DIFFERENTIAL INTERFEROMETRY

1.作为线张力测量的基础研究，高精度地测量了空气/水界面处液体透镜的二面角。(1)测量了长链醇在空气/水界面处的透镜的二面角随温度的变化。透镜的轮廓由理论拉普拉斯方程拟合。(2)所得二面角与由三种界面张力计算的二面角非常接近。这表明角度测量精度很高。(3)该方法将三相接触线的上、下角分别测量，可推广应用于线张力的测量。(4)利用角度和界面张力值讨论了空气/乙醇界面的润湿-非润湿转变和水相的侵入.通过购买的显微镜可以观察到不同的干涉图样。(1)在水面上制作了几种有机液体的透镜，观察了它们的干涉图样。发现具有几十微米直径的透镜适合于干涉图案。(2)通过使用辛酸甲酯，我们一直在寻找最佳的实验条件。

1. The dihedral angle of liquid lens at the air/water interface was measured with a high accuracy as a basic research of line tension measurement.(1) The dihedral angle of a lens of long chain alcohol at the air/water interface was measured as a function of temperature. The profile of the lens was fitted by the theoretical Laplace equation.(2) The dihedral angles obtained were found to be very close to those calculated from the three kinds of interfacial tensions of the system. This shows that the angles were measured with a high accuracy.(3) The upper and lower angles of the three phase contact line were measured separately and therefore this method is able to extend to the measurement of line tension.(4) The wetting-nonwetting transition and intruding of water phase onto the air/alcohol interface were discussed by using the angles and interfacial tension values.2. It became possible to observe the differential interference patterns by the microscope purchased.(1) The lenses of several kinds of organic liquids were made on water surface and the interference patterns were observed. It was found that a lens having the diameter of several ten micrometer was suitable for the interference pattern.(2) By using methyl octanoate, we have been looking for the optimum experimental conditions.