Effect of MXene Nanosheet Dispersed Phases on the Fabrication of Polyamide Nanofiltration Membranes

The effects of different dispersed phases of MXene nanosheets on polyamide nanofiltration membranes, which was first reported in this investigation, are still unclear. We found that when the MXene nanosheets were dispersed into the aqueous phase, the cross-linking degree of the interfacial polymerization (IP) reaction was low, thereby forming a rough and thin polyamide layer with nanovoids, which increased the pure water flux to 14.1 L m2– h–1 bar–1. When the MXene nanosheets were dispersed into the organic phase, the IP reaction was more thorough with a high degree of cross-linking. Therefore, the salt rejection was higher, with 99.1% of Na2SO4 rejection. We believe that different dispersed phases for 2D nanosheets had different impacts on the IP reaction and polyamide layer and we hope this study can provide ideas for selecting a suitable dispersed phase to develop optimization strategies.