(4oq) Mild Temperature Regulated Highly Stable Graphene Oxide Membrane for Molecular

Graphene oxide (GO) exhibits considerable potential for addressing global water scarcity issues due to its ultrathin structure and abundance of oxygenated functional groups, making it an attractive material for nanofiltration membrane development. Nonetheless, challenges persist regarding the stability of GO membranes in aqueous environments and their sustained performance over time, posing significant hurdles to efficient mass transfer. In this study, we present a rapid fabrication method for an ultrathin GO membrane on a nylon substrate using vacuum filtration, achieving completion within 5 minutes. Our investigation reveals that drying GO/nylon membranes at 70°C significantly enhances their stability in aqueous solutions compared to those dried at room temperature. Immersion tests conducted over a 20-day period demonstrate that the GO/nylon membrane dried at room temperature becomes detached from the substrate within 12 hours, while the membrane dried at 70°C remains intact for over 20 days without any signs of deterioration, attributed to the thermally induced equilibrium in electrostatic repulsion that stabilizes the GO membrane. This optimized membrane exhibits improved operating duration, selectivity, and permeability. Specifically, it demonstrates near-complete rejection of organic dyes (~100%) and high selectivity for sulfate salts such as Na₂SO₄ and MgSO₄ (>80%). Furthermore, the membrane sustains continuous operation for over 60 hours with only a 30% decline in water permeability and complete dye rejection. Our findings underscore the importance of moderate temperature drying for enhancing separation performance and membrane stability, suggesting broad applicability of this drying technique across various fields.

Research Interests: design, synthesis and characterization of porous materials for separation, energy storage and catalyst application.

Teaching Interest: Electrochemistry, thermodynamics, chemical kinetics and material processing