Effective cross-linking strategy for graphene oxide membrane with high structural stability and enhanced separation...

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Graphene oxide (GO) membranes offer potential for water treatment but suffer from poor structural stability.
• Developing robust GO membranes is crucial for practical applications in separation technologies.

Purpose of the Study:

• To develop a facile and effective cross-linking strategy to improve the structural stability and separation performance of GO membranes.
• To investigate the efficacy of DL-Tyrosine/amidinothiourea and (3-Aminopropyl) triethoxysilane as cross-linking agents.

Main Methods:

• Cross-linking of GO nanosheets and porous alumina substrate using specific chemical agents.
• Fourier transform infrared spectroscopy (FTIR) for analyzing chemical group evolution.
• Ultrasonic treatment and soaking experiments to assess structural stability.
• Performance evaluation through pure water flux, NaCl permeation, and rejection tests.

Main Results:

• The GO membrane cross-linked with amidinothiourea demonstrated exceptional structural stability.
• Achieved a pure water flux of approximately 109.6 L·m⁻²·h⁻¹·bar⁻¹.
• Showcased superior separation performance with 50.8% NaCl rejection and 86.8 L·m⁻²·h⁻¹·bar⁻¹ permeation flux for a 0.1 g L⁻¹ NaCl solution.
• Long-term filtration experiments confirmed great operational stability.

Conclusions:

• The cross-linking approach significantly enhances the structural stability of GO membranes.
• The developed GO membrane exhibits high performance for water treatment applications.
• This method presents a promising strategy for fabricating stable and efficient GO-based membranes for water purification.