SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2021, Vol. 39 ›› Issue (11): 96-102.DOI: 10.1016/j.cjche.2020.08.055

• Separation Science and Engineering • Previous Articles     Next Articles

Monitoring the spontaneous wetting process of hydrophobic microporous membrane assisted by alternating current impedance spectroscopy

Juntian Xiao1, Qian Sun2, Liying Liu1, Zhongwei Ding1   

  1. 1 Beijing Key Laboratory of Membrane Science and Technology, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China;
    2 Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2020-06-28 Revised:2020-08-12 Online:2021-12-27 Published:2021-11-28
  • Contact: Zhongwei Ding
  • Supported by:
    Fanatical support from the National Natural Science Foundation of China (21576011) and the kind supply of electrochemical workstation from Prof. Zhonghua Xiang are gratefully acknowledged.

Monitoring the spontaneous wetting process of hydrophobic microporous membrane assisted by alternating current impedance spectroscopy

Juntian Xiao1, Qian Sun2, Liying Liu1, Zhongwei Ding1   

  1. 1 Beijing Key Laboratory of Membrane Science and Technology, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China;
    2 Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
  • 通讯作者: Zhongwei Ding
  • 基金资助:
    Fanatical support from the National Natural Science Foundation of China (21576011) and the kind supply of electrochemical workstation from Prof. Zhonghua Xiang are gratefully acknowledged.

Abstract: In the process of membrane absorption, spontaneous wetting of hydrophobic microporous membrane causes membrane modification and increases membrane phase mass transfer resistance, which have attracted wide interest. However, due to the limitations of previous testing methods, the study of the spontaneous membrane wetting process is limited. Herein, we present a method for monitoring spontaneous membrane wetting by measuring its alternating current (AC) impedance. The impedance tests of the PVDF flat membranes and hollow fiber membranes were conducted in a two-electrode system. The results of equivalent circuit fitting indicate that the impedance value of the unwetted membrane is about 1.02×1010 Ω, which is close to the theoretical value of 1.4×1010 Ω, and this method can quantify the electrochemical impedance value of membranes with different degrees of spontaneous wetting. In addition, a method of impedance test for real-time monitoring of spontaneous wetting was designed. During the experiment, the timeliness and continuity of this method are confirmed with exact judgment under different conditions. In future work, the impedance data will be used to build model to predict the percentage of membrane wetting degree.

Key words: Alternating current impedance, Spontaneous membrane wetting, Hydrophobic membrane, Dynamic monitoring

摘要: In the process of membrane absorption, spontaneous wetting of hydrophobic microporous membrane causes membrane modification and increases membrane phase mass transfer resistance, which have attracted wide interest. However, due to the limitations of previous testing methods, the study of the spontaneous membrane wetting process is limited. Herein, we present a method for monitoring spontaneous membrane wetting by measuring its alternating current (AC) impedance. The impedance tests of the PVDF flat membranes and hollow fiber membranes were conducted in a two-electrode system. The results of equivalent circuit fitting indicate that the impedance value of the unwetted membrane is about 1.02×1010 Ω, which is close to the theoretical value of 1.4×1010 Ω, and this method can quantify the electrochemical impedance value of membranes with different degrees of spontaneous wetting. In addition, a method of impedance test for real-time monitoring of spontaneous wetting was designed. During the experiment, the timeliness and continuity of this method are confirmed with exact judgment under different conditions. In future work, the impedance data will be used to build model to predict the percentage of membrane wetting degree.

关键词: Alternating current impedance, Spontaneous membrane wetting, Hydrophobic membrane, Dynamic monitoring