Preparation of high flux thin film composite polyamide membrane: The effect of alkyl phosphate additives during interfacial polymerization

Thin film composite (TFC) polyamide membranes have been used and progressed for desalination and pressure retarded osmosis. A preparation method of TFC polyamide nanofiltration (NF) membranes with enhanced flux is reported. The polyamide TFC NF membrane was fabricated by adding tributyl phosphate (TBP) and triphenyl phosphate (TPP) to an organic solution containing trimesoyl chloride (TMC) during an interfacial polymerization process. The membrane test was performed using a 2000 ppm of sodium chloride solution and a cross-flow permeation cell. The addition of TBP to the TMC organic solution exhibited much higher water flux than that of TPP. The resulting membrane using TBP showed a remarkably increased water flux and a slightly reduced rejection of sodium chloride. From SEM and AFM data, the surface morphologies of the TFC polyamide NF membranes were considerably changed compared to the membrane prepared without addition of TBP in the TMC organic solution.

Graphical abstractSEM images of the surface morphologies of the TFC polyamide membranes with (a) no TBP and (b) 0.6 wt.% TBP as an additive in the organic solution.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► TBP and TPP were added during an interfacial polymerization for polyamide membranes. ► The membranes using TBP showed a remarkably increased flux and a reduced rejection of NaCl. ► From SEM and AFM data, the surface morphologies of the NF membranes were considerably changed.