Minimizing structural parameter of thin film composite forward osmosis membranes using polysulfone/halloysite nanotubes as membrane substrates

Improved performance of thin-film composite membrane with PVDF/PFSA substrate for forward osmosis process

“…The result shows that, although the water flux is slightly lower compared with those using DI water feed solution ( Fig. 10 (a)), mainly because of the reduced osmotic pressure gradient across the TFC membrane with the simulated seawater as feed solution (0.6 M NaCl), it is still considerably high (36.9 LMH with 4 M NaCl draw solution) and comparable with those in previous works [12,13,41]. The result indicates that the TFC membrane based on the PVDF/PFSA substrate with a good water flux could be a suitable candidate of FO membrane for applications of the seawater desalination.…”

“…9. It can be seen that, the water flux increases The ICP impact in FO process can be evaluated appropriately by the structure parameter S, and a lower S value generally indicates the subdued ICP effect, favoring a higher FO water flux in actual applications [6,7,13]. As listed in Table 5, the S parameter of the resultant TFC samples exhibits an overall decreasing tendency with the increasing PFSA content in the membrane substrate (except for MT-5), which should be resulted from the enhanced hydrophilicity, higher porosity and less tortuosity of the substrate as aforementioned.…”

“…Later, the thin film composite (TFC) membranes has drawn extensive concerns in FO processes in virtue of its higher water flux, superior salt rejection, good mechanical strength, long-term stability, and good applicability in practical processes [9,10]. The typical TFC membrane generally consists of two parts, namely a porous substrate with sufficient mechanical strength to achieve a high water flux and long-term stability, and a top polyamide (PA) selective layer formed via interfacial polymerization between the amine aqueous solution and the acyl chloride organic solution [11][12][13][14][15][16][17]. Over the past decades, many studies have been explored to optimize the selective layer with a uniform and dense morphology as well as a low fouling tendency, via changing the reactive monomers and additives [18][19][20].…”

“…The higher surface roughness of PVDF/PFSA substrate may further lead to a higher surface roughness of the TFC membrane[13]. AFM images of the top surface of TFC membranes with PVDF and PVDF/PFSA substrates.3.3 Effect of PFSA loading on performance of resultant TFC membranes3.3.1 Reverse osmosis test of PVDF/PFSA TFC membranesTable 5lists the intrinsic separation properties of the resultant TFC membranes including salt rejection (R S ), water permeability (A) and salt permeability (B).…”

Interforce initiated by magnetic nanoparticles for reducing internal concentration polarization in CTA forward osmosis membrane

“…2 Contrary to RO process, FO uses osmotic gradient pressure as driving force resulting in low membrane fouling and energy consumption. [5][6][7][8][9] Cellulose acetate (CA) and CTA are the most widely used FO material for their good resistance to chlorine and hydrophilicity. 4 They are FO membrane, draw solute, ICP, reverse solute diffusion and membrane fouling.…”