Nafion膜表面亲水性研究

Study on the Hydrophilicity of Nafion Membrane Surface

Ｎａｆｉｏｎ膜在电化学体系中的应用越来越广泛，而其表面亲水性往往直接影响着使用性能．本文介绍一种适宜于表征Ｎａｆｉｏｎ膜表面亲水性的接触角测量方法，即束缚气泡法，并讨论了该膜与水溶液接触角的滞后现象、溶液表面张力的影响，简介了用全氟表面活性剂改善Ｎａｆｉｏｎ膜表面亲水性的尝试．

Due to its high chemical stability and ion selective permeability, Nafion membrane has been applied in many electrochemical systems. The surface hydrophilicity is one of the main factors affecting its performance. In this paper, the bound bubble method is introduced as a suitable way to measure the contact angles between Nafion membrane and various aqueous solutions. During the measurement, Nafion membrane is saturated with given electrolyt solution. The hysteresis of the contact angles observed in the measurement is attributed to the co existance of hydrophobic and hydrophilic domains at the membrane surface. The effect of the solution surface tension on the contact angle is demonstrated. It is shown that Nafion membrane can be rendered more hydrophilic by modification with sulfonic acid type perfluorinated surfactant.