Theoretical and experimental study of high performance thin-film nanocomposite nanofiltration membranes by introducing calcium carbonate nanoparticles

The synthesis of high selectivity and permeance thin-film composite (TFC) membranes frequently encounters a significant challenge in balancing the permeance-selectivity trade-off. Recent research has demonstrated that the incorporating of nanomaterials into fabricated thin film nanocomposite (TFN) membranes is a feasible strategy to overcome this permeance-selectivity trade-off. Here we proposed using calcium carbonate nanoparticles (n-CaCO3) as organic phase additives to modulate interfacial polymerization (IP) reaction to prepare TFN membrane. Molecular dynamics (MD) simulation was employed to explore the effects of n-CaCO3 addition on the dispersion of organic phase monomers and on the diffusion of water phase monomers. The prepared TFN membrane (TFN-0.03) loaded with very little n-CaCO3 (0.03 wt%) exhibited a high permeability of 16.9 +/- 0.5 L m(-2) h(-1) bar(-1), which was 1.7 times greater than that of the TFC membrane, and also maintained a high selectivity (Na2SO4 rejection: 98.8 %). Our work furnishes the theoretical and experimental basis for the development of high performance TFN nanofiltration (NF) membranes.