关键词: Nafion膜, 表面亲水性, 接触角

Abstract: 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.

Key words: Nafion membrane, Surface hydrophilicity, Contact angle