Volatile Sieving Using Architecturally Designed Nanochannel Lamellar Membranes in Membrane Desalination

Thermally driven membrane desalination processes have garnered significant interest for their potential in the treatment of hypersaline wastewater. However, achieving high rejection rates for volatiles while maintaining a high water flux remains a considerable challenge. Herein, we propose a thermo-osmosis-evaporation (TOE) system that utilizes molecular intercalation-regulated graphene oxide (GO) as the thermo-osmotic selective permeation layer, positioned on a hydrophobic poly(vinylidene fluoride) fibrous membrane serving as the thermo-evaporation layer. By carefully constructing architectural interlaminar nanochannels of GO membranes via simultaneously confining small molecules to enlarge the interlayer spacing and incorporating polymers within the GO interlayers to create a dense network, the resultant demonstrates a rejection rate of 100% for NaCl and 97.41% for volatile phenylamine, with a water permeance of 63.80 L m-2 h-1 at a temperature difference of 40 °C, outperforming previously reported GO-based membranes. Simulation and calculation results reveal that the polymer network between the GO interlayers facilitates the high-efficiency separation of nonvolatile ions and volatile molecules, while the enlarged channels reduce vapor diffusion resistance. This study provides valuable insights for the design of advanced membranes and serves as inspiration for the continued development of the TOE system for complex hypersaline wastewater treatment.