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

1. 高精度地测量了液透镜在气/水界面处的二面角，作为线张力测量的基础研究。(1)测定了长链醇透镜在空气/水界面处的二面角随温度的变化。用理论拉普拉斯方程拟合了透镜的轮廓。(2)得到的二面角与由三种界面张力计算得到的二面角非常接近。这说明测量角度的精度很高。(3)三相接触线的上、下角分别测量，因此该方法可以推广到线张力的测量。(4)通过角度和界面张力值，讨论了水相在气醇界面上的润湿-非润湿转变和侵入。用购买的显微镜观察微分干涉图样成为可能。(1)在水面制作几种有机液体的透镜，观察其干涉图样。研究发现，直径为几十微米的透镜适合于干涉图样。(2)以辛酸甲酯为原料，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.