Quantitative analysis of ion crossover in bacterial cellulose membranes separating diffusion behaviour from membrane
Sara Zdovc1, Priya Mukherjee2, Selestina Gorgieva1
1Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, 2000, Maribor, Slovenia.
International Journal of Biological Macromolecules
|June 27, 2026
Summary
Bacterial cellulose membranes offer tunable ion transport for bioelectrochemical systems. Optimizing membrane thickness and structure, like with graphene oxide composites, controls ion crossover for enhanced efficiency.
Area of Science:
- Materials Science
- Electrochemistry
- Chemical Engineering
Background:
- Ion-selective membranes are essential for separating compartments in bioelectrochemical systems (BES) like microbial fuel cells (MFCs).
- Undesired cation crossover in these membranes compromises selectivity, pH stability, and overall system efficiency.
- Bacterial cellulose (BC) membranes are explored as alternatives, but their ion transport characteristics require detailed investigation.
Purpose of the Study:
- To systematically investigate and compare cation transport across various bacterial cellulose (BC)-based membranes and Nafion 117.
- To evaluate the influence of membrane structure, thickness, and composition on ion crossover rates.
- To develop a quantitative framework for designing effective cellulose-based membranes for BES.
Main Methods:
- Fabrication of stacked BC, dispersion-cast BC (dBC), and BC-graphene oxide (dBC-GO) composite membranes.
- Ion crossover experiments using different cation types (monovalent and divalent).
- Analysis of ion transport using numerical solutions of Fick's law to determine diffusion coefficients (Dg).
- Thickness-normalized analysis and predictive modeling for ion crossover.
Main Results:
- Ion diffusion coefficients (Dg) in membranes were significantly lower than in bulk water, indicating strong ion-membrane interactions.
- Monovalent ions exhibited faster diffusion than divalent cations due to valence and adsorption effects.
- While thicker membranes reduced crossover rates, dBC membranes showed higher diffusion coefficients than Nafion 117.
- Modeling provided estimates for membrane thickness to limit ion crossover to 1% within 6 hours.
Conclusions:
- Membrane microstructure and thickness are critical factors in regulating ion crossover in BES.
- Cellulose-based membranes, particularly dBC and dBC-GO composites, show potential for efficient ion selectivity in BES.
- The study provides a quantitative basis for designing tailored cellulose membranes for improved performance in microbial electrochemical technologies.
Related Concept Videos
01:24Protein Diffusion in the Membrane
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
01:15Dialysis
Dialysis is a diffusion-based purification process that separates analyte molecules from a complex matrix. This is accomplished by allowing molecules in the solution to pass through a semipermeable membrane into a liquid on the other side. The membrane is usually made of cellulose acetate or cellulose nitrate, and the second liquid must be miscible with the solution. Ions (e.g., chloride or sodium) or organic molecules (e.g., glucose) can pass through the membrane pores, which generally have...