Effect of Reaction\nInterface Structure on the Morphology\nand Performance of Thin-Film Composite Membrane

Thin-film composite (TFC) membrane has been extensively\nutilized\nand investigated for its excellent properties. Herein, we have constructed\nan active layer (AL) containing cave-like structures utilizing large\nmeniscus interface. Furthermore, the impact of interface structure\non the growth process, morphology, and effective surface area of AL\nhas been fully explored with the assistance of sodium dodecyl benzenesulfonate\n(SDBS). The SDBS-induced nanobubbles continuously facilitated the\nmigration of the top layer of AL toward the upper space. During this\nprocess, the surface area of sunken AL in the cave-like structures\ninitially exhibited an increase and then a decrease. Additionally,\nthe larger interface significantly enhanced the surface area and delayed\nthe rise in the top layer of AL in the cave-like structures. Therefore,\nthe TFC membrane, utilizing a substrate with a pore size of 1.00 μm\nand assisted by 0.30 mM SDBS, exhibited remarkable flux enhancement\n(>63%) and reduced reverse sodium salt flux (>35%) in a forward\nosmosis\nsystem. Moreover, the roughness factor was introduced to directly\nquantify the effective surface area, which had a good correlation\nwith the water flux. Our findings demonstrated the significant potential\nof utilizing substrates with a large pore size to overcome the inherent\nlimitations of the TFC membrane.