One-step facile fabrication of mechanical strong porous boron nitride nanosheets–polymer electrospun nanofibrous membranes for repeatable emulsified oil/water separation

Abstract

The separation of oily wastewater with its growing commercial demand is a big challenge due to a lot of oily wastewater produced in the petroleum industry and draining pollutes the environment. Porous boron nitride nanosheets (BNNS) is a highly efficient adsorbent material for organic pollutants especially for oily pollutants due to its high surface area. However, the nanosheets assembled membranes have a relatively low mechanical properties and it is hard to be collected after removing organic pollutants. In this work, a novel porous boron nitride nanosheets/polyacrylonitrile (PAN) nanofibrous membrane was fabricated through a simple one-step electrospinning strategy for mechanical strong and repeatable emulsified oil/water separation. Compared to pristine PAN membrane, membrane with porous BNNS addition of 4 wt% shows a slight lower permeability of 12885 ± 131 L μm m−2 h−1 bar−1, but with much higher separation efficiency of 99% for pump oil/water emulsions. In addition, the membranes demonstrated excellent mechanical performance as increasing porous BNNS loading, with improved mechanical strength by about 49.6% from 13.3 MPa to 19.9 MPa, enhanced Young’s modulus by about 456.2% from 25.1 to 139.6 MPa, respectively. Therefore, the membrane can be easily recycled and used for more than 25 cycles without significant change.