Related Experiment Video
Updated: Jan 6, 2026
08:06
Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone
Published on: February 23, 2017
8.9K
Removal of model dyes on charged UF membranes: Experiment and simulation
Jie Ding1, Liangtao Pu1, Di Zou2
1State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, 210023, China.
Chemosphere
|October 2, 2019
Summary
This study developed a novel charged membrane using PANI/PVDF for efficient removal of charged pollutants. Electrochemical control significantly enhanced membrane performance, offering a new approach for water purification.
Area of Science:
- Materials Science
- Chemical Engineering
- Environmental Science
Background:
- Charged ultrafiltration (UF) membranes offer advantages over uncharged membranes, including higher solute rejection and flux at lower operating pressures.
- Existing charged membranes face limitations in tunable performance and broad applicability for diverse charged contaminants.
Purpose of the Study:
- To develop and characterize a novel electrochemically controllable charged UF membrane composite (PANI/PVDF).
- To investigate the impact of electrochemical regulation on membrane permeability and rejection of charged dyes.
- To establish a predictive model for membrane performance based on steric and electric repulsion effects.
Main Methods:
- Fabrication of a composite membrane using polyaniline (PANI) and polyvinylidene fluoride (PVDF).
- Electrochemical control of amine/imine functional groups in PANI to modulate surface charge.
- Measurement of membrane permeability and rejection ratios for Congo Red (CR2-) under varying electrochemical potentials.
- Development and validation of a fixed-charge model incorporating steric and electric repulsion.
Main Results:
- The PANI/PVDF membrane exhibited significantly enhanced permeability (19.6 to 183.3 L m⁻² h⁻¹ bar⁻¹) and CR2- rejection (3.4% to 74%) upon electrochemical regulation.
- Surface potential modulation from -12.21 mV to -25.26 mV improved performance, with CR2- rejection reaching up to 93%.
- A fixed-charge model accurately described membrane performance and the role of controllable surface charge, validated by a contour map.
Conclusions:
- Electrochemical control offers a powerful strategy to tune the performance of charged membranes.
- The developed PANI/PVDF membrane demonstrates high efficiency in removing charged pollutants.
- The established model provides a valuable tool for designing and optimizing charged membranes for various separation applications.
