A novel thin film composite forward osmosis membrane prepared from PSf–TiO2 nanocomposite substrate for water desalination

Synthesis and characterization of flat-sheet thin film composite forward osmosis membranes

Influence of monomer concentrations on the performance of polyamide-based thin film composite forward osmosis membranes

Synthesis and characterization of novel thin film composite forward osmosis membrane using charcoal-based carbon nanomaterials for desalination application

Fabrication of thin film composite forward osmosis membrane using electrospun polysulfone/polyacrylonitrile blend nanofibers as porous substrate

Thin film composite forward osmosis membranes based on polydopamine modified polysulfone substrates with enhancements in both water flux and salt rejection

Middle support layer formation and structure in relation to performance of three-tier thin film composite forward osmosis membrane

Hydrophilic polyvinyl alcohol coating on hydrophobic electrospun nanofiber membrane for high performance thin film composite forward osmosis membrane

Effect of sulphonated polyethersulfone substrate for thin film composite forward osmosis membrane

Synthesis and characterization of thin film nanocomposite forward osmosis membrane with hydrophilic nanocomposite support to reduce internal concentration polarization

Preparation of polyamide thin film composite forward osmosis membranes using electrospun polyvinylidene fluoride (PVDF) nanofibers as substrates

The incorporation of inorganic nanoparticles into thin film composite forward osmosis (TFC FO) membranes is an effective method to alleviate internal concentration polarization (ICP) and enhance the flux performance of the FO membrane. In this paper, synthetic hydrophilic rod-like porous nano-hydroxyapatites (PNHAs) were doped into polysulfone (PSf) casting solution to form support layer by phase inversion; further interfacial polymerization was carried out to prepare a high performance TFC FO membrane. The results showed that the incorporation of PNHAs not only improved the thickness, porosity, hydrophilicity, and connectivity of the support layer, but also enhanced the roughness of the active layer. The measured mass transfer parameters prove that these improvements were beneficial. Further FO experiments showed that when using deionized water as the feed solution and 1mol/L NaCl as the draw solution, TFN 0.75 showed higher water flux than TFC FO membrane in both AL-FS (18.5 vs 7.16 L/m2·h) and AL-DS (33.26 vs 9.93 L/m2·h) modes. Reverse salt flux had not increased significantly. At the same time, TFN 0.75 (697 μm vs 1,960 μm) showed the smallest structural parameter. This study shows that PNHA is a suitable nanomaterial for mitigating the ICP effect of FO membranes.

High flux polyamide thin film composite forward osmosis membranes prepared from porous substrates made of polysulfone and polyethersulfone blends

In this study, robust and defect-free thin film composite (TFC) forward osmosis (FO) membranes have been successfully fabricated using ceramic hollow fibers as the substrate. Polydopamine (PDA) coating under controlled conditions is effective to reduce the surface pores of the substrate and make the substrate smooth enough for the interfacial polymerization. The pure water permeability (A), solute permeability (B) and structural parameter (S) of the resultant FO membrane are 0.854 L·m-2h-1bar-1 (LMH/Bar) 0.186 L·m-2h-1 (LMH) and 1720 µm, respectively. The water flux and reverse draw solute flux are measured using NaCl and proprietary ferric sodium citrate (FeNaCA) draw solutions at low and high osmotic pressure ranges. With increasing the osmotic pressure, higher water flux is obtained but its increase is not directly proportional to the increase in the osmotic pressure. At the membrane surface, the effect of dilutive concentration polarization is much less serious for FeNaCA draw solutions. At an osmotic pressure of 89.6 bar, the developed TFC membrane generates water fluxes of 11.5 and 30.0 LMH using NaCl and synthesized FeNaCA draw solutions. The corresponding reverse draw solute flux is 7.0 g·m-2h-1 (gMH) for NaCl draw solution but it is not detectable for FeNaCA draw solution. This means that the developed TFC FO membranes are defect free and their surface pores are at molecular level. The performance of the developed TFC FO membranes are also demonstrated for the enrichment of BSA protein.

In this study, robust and defect-free thin film composite (TFC) forward osmosis (FO) membranes have been successfully fabricated using ceramic hollow fibers as the substrate. Polydopamine (PDA) coating under controlled conditions is effective in reducing the surface pores of the substrate and making the substrate smooth enough for interfacial polymerization. The pure water permeability (A), solute permeability (B), and structural parameter (S) of the resultant FO membrane are 0.854 L·m–2·h−1·bar−1 (LMH/Bar), 0.186 L·m–2·h−1 (LMH), and 1720 µm, respectively. The water flux and reverse draw solute flux are measured using NaCl and proprietary ferric sodium citrate (FeNaCA) draw solutions at low and high osmotic pressure ranges. As the osmotic pressure increases, a higher water flux is obtained, but its increase is not directly proportional to the increase in the osmotic pressure. At the membrane surface, the effect of dilutive concentration polarization is much less serious for FeNaCA-draw solutions. At an osmotic pressure of 89.6 bar, the developed TFC membrane generates water fluxes of 11.5 and 30.0 LMH using NaCl and synthesized FeNaCA draw solutions. The corresponding reverse draw solute flux is 7.0 g·m–2·h−1 (gMH) for NaCl draw solution, but it is not detectable for FeNaCA draw solution. This means that the developed TFC FO membranes are defect-free and their surface pores are at the molecular level. The performance of the developed TFC FO membranes is also demonstrated for the enrichment of BSA protein.

Evaluation of ethanol as draw solute for forward osmosis (FO) process of highly saline (waste)water