Inkjet printed single walled carbon nanotube as an interlayer for high performance thin film composite nanofiltration membrane

Inkjet printing process enables rapid deposition of inks with precise amount and location. Moreover, the process can be automated and provide control such as repetitive printing of the inks. Utilizing the advantageous features of the inkjet printing process, we demonstrate the synthesis of thin film composite (TFC) flat-sheet membrane for NF application where single walled carbon nanotube (SWCNT) was deposited via an inkjet printing process, acting as an interlayer between the polyamide (PA) selective layer and polyethersulfone (PES) MF membrane support. By controlling the number of SWCNT printings on the PES membrane, we investigated how the SWCNT interlayer thickness influences the formation of PA selective layer. The best membrane performance was achieved from the TFC membrane synthesized using 15 cycles of SWCNT printing, where both high water flux (18.24 +/- 0.43 L m(-2) h(-1) bar(-1)) and the high Na2SO4 salt rejection (97.88 +/- 0.33%) rates were demonstrated. SWCNT interlayer provided highly porous, interconnected structure with uniform pore size distribution which led to the formation of a defect-free ultrathin PA selective layer. Designing of TFC membrane using the SWCNT deposition via inkjet printing is the new approach and successfully demonstrated the significant improvement in the NF membrane performances.

Automated summary

This study demonstrated the synthesis of a thin film composite membrane using inkjet printing to deposit single-walled carbon nanotubes, resulting in a membrane with high water flux and salt rejection rates. The controlled deposition of SWCNT provided a highly porous interlayer that led to the formation of a defect-free ultrathin selective layer, showing significant improvement in NF membrane performance.