Electrostatically coupled SiO₂ nanoparticles/poly (L-DOPA) antifouling coating on a nanofiltration membrane

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Membrane fouling is a significant challenge in nanofiltration (NF) processes, increasing operational costs and reducing efficiency.
• Thin film composite (TFC) membranes are widely used but susceptible to fouling, necessitating improved antifouling strategies.

Purpose of the Study:

• To enhance the fouling resistance of TFC nanofiltration membranes.
• To develop an effective antifouling coating using electrostatically coupled silica dioxide (SiO2) nanoparticles and poly(L-DOPA).

Main Methods:

• Synthesized SiO2 nanoparticles in various sizes and combined them with L-DOPA for coating.
• Applied the coating onto TFC-NF membrane surfaces via recirculated deposition.
• Evaluated membrane properties using Atomic Force Microscopy (AFM) and filtration experiments.
• Assessed biofouling using flow cytometry.

Main Results:

• Coating increased membrane hydrophilicity and reduced surface roughness, decreasing foulant adhesion by 60%.
• Modified membranes exhibited minimal flux decline during filtration, unlike unmodified membranes.
• Biofouling analysis showed a 50% reduction in microbial growth on coated membranes.

Conclusions:

• The SiO2 nanoparticles/poly(L-DOPA) coating effectively improves the antifouling properties of TFC-NF membranes.
• This antifouling strategy shows significant potential for applications in desalination and industrial wastewater treatment.
• Optimized coating conditions enhance membrane performance and longevity.