PVDF mixed matrix membranes by incorporation of ionic liquid and MXene for enhancing permeation and antifouling performance

Abstract

Aiming to enhance permeation and anti-fouling performance of PVDF membrane, IL/PVDF and MXene-IL/PVDF mixed matrix membranes (MMMs) were fabricated by incorporating 1-hexyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ionic liquid (IL) and MXene-IL. The microstructures of IL/PVDF and MXene-IL/PVDF MMMs were characterized by TEM, SEM, FTIR, XRD, and XPS analysis. The performance of the MMMs was evaluated in the dead-end filtration, and results showed that IL addition would increase the pore size and hydrophilicity of IL/PVDF MMMs, thereby enhancing water flux and anti-fouling performance of the MMMs. However, IL would be dissolved out from IL/PVDF MMMs during the filtration process, which would depress the flux recovery rate of the MMMs. For MXene-IL/PVDF MMMs, IL was encapsulated by intercalating into the MXene nanosheets and effectively prevented the loss of IL from Mxene-IL/PVDF MMMs in the running process. MXene-IL/PVDF MMMs had high water flux and antifouling performance, and the maximum flux recovery rate of MXene-IL co-incorporated PVDF MMMs reached 96% after four-cycle filtration, and the corresponding water flux was 129.37 L·m−2·h−1. Compared with PVDF membrane, pure water flux and flux recovery rate of MXene-IL/PVDF mixed matrix membranes increased by 4.37 and 1.83 times, respectively.