Nanonet membranes with nano-mastoid structure for high-performance oily wastewater treatment

The pollution caused by oily wastewater has a severe influence on the human health and ecological environment. However, the present membranes suffer from a bottleneck that it is difficult to synchronously improve the filtration efficiency and permeation flux. It is still of great importance to develop efficient oil-in-water separation membranes. Herein, we have prepared a nanonet membrane (NM) with both nanonet structure and nano-mastoid structure through a combination of phase inversion with electrospinning. Profiting from the structural advantages of network interconnectivity, sub-micrometer pores, and high porosity, the NMs demonstrated outstanding capacity for separating nanoscale oil-in-water emulsions with a prospective separation efficiency (99.2%) and robust permeation flux (24,076 L m-2 h-1). Importantly, benefitting from their good surface wettability and low underwater oil adhesion, the NMs maintained a stable permeation flux (7738 L m-2 h-1) and stable high separation efficiency (99.1%) even after 10 separation cycles. The synthesis of such nanonet membranes may develop new paths for the development of next-generation separation membranes with high performance. image