Superwettable cellulose acetate-based nanofiber membrane with spider-web structure for highly efficient oily water purification

Electrospinning nanofibers membrane has received much attention to remove the insoluble oil from the sewage, while the poor mechanical strength and low oil/water separation efficiency of membranes limit their practical application. Here, we prepared a superwettable deacetylated cellulose acetate (d-CA)-based electrospinning nanofibers membrane simply dipped by bacterial cellulose (BC) and cross-linked with citric acid (CCA) to construct the spider-web structure spontaneously. Compared with the pristine d-CA membrane, the obtained d-CA/BC@CCA membrane exhibits the remarkable oil/water separation performance. The flux and separation efficiency of n-hexane/water emulsion without (SFE) and with (SSE) emulsifier for d-CA/BC@CCA membrane are 9364 L·m-2·h-1·bar-1, 98.34 % and 5479 L·m-2·h-1·bar-1, 99.39 %, respectively, which are mainly attributed to the improved hydrophilicity of its surface and the decreased pore sizes caused by the unique spider-web structure. In addition, d-CA/BC@CCA membrane also possesses the outstanding mechanical properties, the better cycle stability, as well as the excellent durability. This study provides a novel strategy for the construction of the high-performance oil/water separation membrane.