Enhanced Boron Rejection and Permeability in Thin-film Nanocomposite Membranes

Strategic Insights -

Research from China Agricultural University has successfully incorporated graphite-phase carbon nitride (g-C3N4) nanosheets into the polyamide layer of thin-film nanocomposite (TFN) membranes to enhance boron removal and membrane permeability. The new design has shown improved water flux, boron removal, and antifouling performance, making it a promising candidate for large-scale production of seawater reverse osmosis (SWRO) membranes.

Key Takeaways:

  • The incorporation of g-C3N4 nanosheets into the PA layer of TFN membranes resulted in an increased effective separation area, higher crosslinking degree, and increased hydrophilicity, while simultaneously reducing surface roughness and forming a thinner PA layer.
  • The modified membrane exhibited excellent water-salt selectivity, antifouling properties, and chlorine resistance.
  • The optimal g-C3N4 concentration for maximum boron removal and water flux improvement was found to be 150 mg L-1.
  • At this concentration, the boron-removal rate of the g-C3N4-TFN membrane in simulated seawater increased from 72.5% to 90.5%, with water flux improving from 35.8 to 46.8 L m-2 h-1.
  • Molecular dynamics simulations revealed that g-C3N4 reduced the MPD diffusion rate through hydrogen bonding interactions and steric hindrance effect of the g-C3N4 interfacial arrangement.
  • The new membrane design offers a simple and scalable approach for preparing high-performance SWRO membranes.

Statistics:

  • Boron-removal rate of the g-C3N4-TFN membrane in simulated seawater: 90.5%
  • Water flux of the g-C3N4-TFN membrane: 46.8 L m-2 h-1
  • g-C3N4 concentration for optimal performance: 150 mg L-1
  • Increased water flux compared to thin-film composite membrane: 11 L m-2 h-1
  • Increased boron-removal rate compared to thin-film composite membrane: 18%

Sources:

  • Desalination (Elsevier)
  • Enhanced Boron Rejection and Permeability of Thin-film Nanocomposite Membranes Via G-c3n4-tuned Diffusion and Reaction, Desalination, 2025; 610
  • NewsRx. Recent Findings from China Agricultural University Has Provided New Information about Nanocomposites (Enhanced Boron Rejection and Permeability of Thin-film Nanocomposite Membranes Via G-c3n4-tuned Diffusion and Reaction). Nanotechnology Weekly. September 1, 2025; p 2252.