Leaf vein-inspired microfiltration membrane based on ultrathin nanonetworks

• Published in: Environmental science. Nano Vol. 7; no. 9; pp. 2644 - 2653
• Main Authors: Tang, Ning, Si, Yang, Yu, Jianyong, Ding, Bin
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 17.09.2020
• Subjects: Construction; Contamination; Continuous fibers; Diameters; E coli; Freshwater; Freshwater pollution; Inland water environment; Leaves; Membranes; Microfiltration; Nanofibers; Pathogens; Penetration; Phase separation; Pore size; Porosity; Public health; Recyclability; Separation; Titanium dioxide; Veins (plant anatomy)
• ISSN: 2051-8153; 2051-8161
• DOI: 10.1039/d0en00644k

The increasing worldwide contamination of freshwater by pathogenic microbes is one of the key global challenges facing public health. The commonly used technologies are often limited either by non-recyclability or deterioration of porous structures. Herein, an innovative leaf vein-inspired membrane (LVIM) by a nanonetwork structure is constructed by combining vapor-induced phase separation with electrospinning. Through exquisite control of solvents and relative humid conditions, our approach allows the continuous nanoscale network (∼45 nm fiber diameter) to strongly bind with electrospun nanofibers. The resulting LVIMs exhibit integrated properties of desirable pore structures (small pore size of 0.19 μm, high porosity of 93.2%, and favorable interconnectivity) and strikingly low membrane thickness (∼700 nm). Consequently, the LVIMs are capable of effectually capturing sub-micron particles (∼0.3 μm TiO 2 particles) with high efficiency of 99.75% and robust permeation flux of 3907 L m −2 h −1 under an ultralow driving pressure of 5 KPa. More significantly, an outstanding bacterial removal efficiency for E. coli (log reduction value of 8.0) with twice the higher permeation flux (1206 L m −2 h −1 ) than the commercial microfiltration membranes was also achieved for LVIMs. The successful construction of such versatile membranes may act as an inspirational source for the design of next-generation high-performance separation membranes for various separation applications. Leaf vein-inspired membranes with nanonetwork structures were constructed for high-flux water purification under ultralow driving pressures.