Antimicrobial membrane cellulose acetate containing ionic liquid and metal nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Biotechnology

Background:

• Cellulose acetate (CA) membranes are widely used but can be improved for specific applications.
• Incorporating metal nanoparticles offers potential for enhanced functionality, such as antimicrobial properties.
• Ionic liquids (ILs) can be used as processing aids and to modify material properties.

Purpose of the Study:

• To develop novel membrane films incorporating stable metallic nanoparticles (gold, silver, platinum) within a cellulose acetate and ionic liquid matrix.
• To investigate the effect of these nanoparticles on the physical properties and surface area of the membranes.
• To evaluate the antimicrobial efficacy of the developed membranes against common bacteria.

Main Methods:

• Synthesis of stable metallic nanoparticles (Au(0), Ag(0), Pt(0)) with controlled size distributions.
• Fabrication of 20-micrometer thick membrane films by combining nanoparticles, the ionic liquid 1-n-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide (BMI x (NTf)2), and cellulose acetate (CA) in acetone.
• Characterization of membrane physical properties, including surface area, elasticity, tenacity, toughness, and stress at break.
• Antimicrobial testing against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) using membranes with varying metal concentrations.

Main Results:

• Stable metallic nanoparticles (Au(0), Ag(0), Pt(0)) were successfully incorporated into CA/IL membranes.
• The presence of nanoparticles increased the surface area of the CA/IL films.
• Membrane elasticity increased with IL addition, while tenacity and toughness decreased; stress at break remained unaffected.
• Significant antimicrobial activity was observed at metal concentrations as low as 1 mg of metal per 5 g of CA.
• The CA/IL/nanoparticle composite membranes demonstrated enhanced durability and antimicrobial effectiveness against both E. coli and S. aureus.

Conclusions:

• The combination of cellulose acetate, ionic liquid, and metallic nanoparticles creates robust membrane films with potent antimicrobial capabilities.
• These novel materials show promise for applications requiring enhanced antibacterial surfaces and improved material durability.
• The study highlights the synergistic effect of nanoparticles and ionic liquids in conferring desirable properties to membrane materials.