Using Al³⁺ to Tailor Graphene Oxide Nanochannels: Impact on Membrane Stability and Permeability

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Graphene oxide (GO) membranes are promising for separations due to their nanochannels.
• Controlling nanochannel structure and improving aqueous stability are key challenges for GO membrane applications.

Purpose of the Study:

• To develop a simple method for modifying GO membranes using aluminum cations.
• To investigate the impact of aluminum modification on GO membrane stability, nanochannel structure, and permeation properties.

Main Methods:

• Introducing trivalent aluminum cations (Al3+) to GO solutions via aluminum foil oxidation.
• Fabricating self-assembled GO membranes from modified GO sheets.
• Characterizing membrane properties using surface tension, contact angle, AFM, and XPS.

Main Results:

• Al3+ modification increased GO membrane stability in various solvents.
• Membrane permeability to water and propanol decreased.
• Al3+ interaction with oxygenated functional groups enhanced hydrophobicity and reduced intra-sheet spacing.

Conclusions:

• Al3+ modification offers a viable strategy to enhance GO membrane aqueous stability.
• This approach allows for tuning permeation selectivity, enabling applications in vapor separation and fuel purification.