Glutaraldehyde Cross-Linked MXene-Nanocellulose Membrane for Efficient Dye/Salt Separation

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Two-dimensional (2D) membranes, such as those made from MXenes (laminated carbides and nitrides), are crucial for separation technologies.
• Improving the water flux and selectivity of these membranes is a key challenge in materials science.
• Existing methods often struggle to balance permeability with rejection capabilities.

Purpose of the Study:

• To develop a novel strategy for preparing high-performance MXene membranes with enhanced nanochannels.
• To investigate the role of cellulose nanocrystals (CNC) and glutaraldehyde cross-linking in modifying MXene membrane properties.
• To achieve superior water flux and selectivity for efficient separation applications.

Main Methods:

• Intercalation of cellulose nanocrystals (CNC) into the MXene interlayers to expand spacing.
• Cross-linking the MXene membrane with glutaraldehyde to improve structural stability.
• Optimization of the intercalation and cross-linking process for enhanced membrane performance.

Main Results:

• The prepared MXene membrane exhibited loose nanochannels, significantly increasing water permeate flux by 2.1 times compared to unmodified MXene membranes (96.8 L m^-2 h^-1).
• The membrane demonstrated excellent selectivity, achieving a methyl blue rejection rate of approximately 99.6% and a NaCl rejection rate below 5.0%.
• The glutaraldehyde cross-linking effectively enhanced the overall stability of the modified MXene membrane.

Conclusions:

• The proposed strategy of using CNC intercalation and glutaraldehyde cross-linking is a versatile method for fabricating high-performance 2D membranes.
• This approach offers a promising pathway for developing advanced materials for water treatment and other separation-intensive industries.
• The enhanced flux and selectivity highlight the potential of this novel membrane preparation technique for practical applications.