污秽物表面张力的测量及其对接触角的影响研究

Research on the Measurement of Surface Tension of Contamination and the Influence of Surface Tension on Contact Angle

在实际电力系统线路运行环境中,硅橡胶表面的不同染污程度和水滴吸收污层盐分共同作用影响硅橡胶表面液滴接触角的大小。采用悬滴法测量盐溶液表面张力和理论计算法测量污层表面张力,并对比盐溶液在洁净硅橡胶表面的接触角和水在污层表面的接触角,分别分析液体表面张力和固体表面张力对液滴形态的影响规律。结果表明,对于盐溶液液滴,随着NaCl浓度增大,其表面张力增大,盐液滴在洁净硅橡胶表面的接触角增大;对于污层表面,由于盐密增大,固体表面张力增大,故即使水液滴吸收了污层中盐分使得自身表面张力增大,液滴接触角仍减小;并且在实际运行情况下,液滴接触角受污层性质的影响较大。

In the actual operation environment of the power system lines, the contact angle is affected by different contamination condition of silicone rubber surface and water droplets absorbing salt of contamination layer. Through measuring the surface tension of saline solution by hanging drop method and surface tension of contamination layer by theoretical calculation method, the impact of surface tension of liquid and solid to shape of droplets is analyzed considering the pollution, also by comparing the contact angle of saline solution on clean surface and water on contamination layer. The results show that surface tension of NaCl solution and contact angle of droplets on clean surface increases with the increase of its concentration. For the contamination layer, surface tension of solid increases and contact angle still decreases with the increase of ESDD, even though water droplets absorbed the salt in the layer to increase the surface tension. Furthermore, under the actual operating conditions, the impact of characteristic of contamination layer to contact angle is greater.