In situ polymerized superhydrophobic and superoleophilic nanofibrous membranes for gravity driven oil–water separation

Abstract

Creating an efficient, cost-effective method that can provide simple, practical and high-throughput separation of oil-water mixtures has proved extremely challenging. This work responds to these challenges by designing, fabricating and evaluating a novel fluorinated polybenzoxazine (F-PBZ) modified nanofibrous membrane optimized to achieve gravity driven oil-water separation. The membrane design is then realized by a facile combination of electrospun poly(m-phenylene isophthalamide) (PMIA) nanofibers and an in situ polymerized F-PBZ functional layer incorporating SiO2 nanoparticles (SiO2 NPs). By employing the F-PBZ/SiO2 NP modification, the pristine hydrophilic PMIA nanofibrous membranes are endowed with promising superhydrophobicity with a water contact angle of 161° and superoleophilicity with an oil contact angle of 0°. This new membrane shows high thermal stability (350 °C) and good repellency to hot water (80 °C), and achieves an excellent mechanical strength of 40.8 MPa. Furthermore, the as-prepared membranes exhibited fast and efficient separation of oil-water mixtures by a solely gravity driven process, which makes them good candidates for industrial oil-polluted water treatments and oil spill cleanup, and also provided new insights into the design and development of functional nanofibrous membranes through F-PBZ modification.

The electrospinning of the copolymer of styrene and butyl acrylate for its application as oil absorbent

“…Electrospun fibrous materials are of great advantage to oil absorption rate for the reason that the diameter of electrospun fibers can reach nanometer level (Zhu et al 2011). In recent years, some polymers, such as polyacrylonitrile (Su et al 2012; Liu et al 2014), poly(m-phenylene isophthalamide) (Tang et al 2013), and cellulose acetate (Shang et al 2012), have been electrospun into fibrous materials and used as oil absorbents to separate oil from water. Polystyrene, as a commonly solvent-soluble and thermoplastic polymer, has more excellent electrospinnability in comparison with other polymers, thus electrospun polystyrene fibrous material has been used widely as oil absorbent (Lin et al 2012, 2013; Lee et al 2013; Wu et al 2012).…”

Designing electrospun nanocomposite poly(vinylidene fluoride) mats with tunable wettability

“…Many efforts have been made to prepare superhydrophobic membranes for oil-water separation. These efforts rely on the contrasting wettability of the surface towards water and oil; that is, a membrane which repels water and adsorbs oil [44][45][46]. However, fabricating such membranes based on PVDF and using a simple process such as electrospinning has not been attempted.…”

Editorial overview: Separation engineering: Recent advances in separation science and technology

“…A nanofiber membrane can show 3-7 times higher pure water flux than a conventional membrane [11]. Nanofiber microfiltration membranes consisting of a combined super-hydrophobic layer and super-hydrophilic electrospun nanofibrous scaffold structure have been designed and demonstrated for oil and water separation [12][13][14] and for treating and separating water-in-oil [15] and oil-in-water [16,17] micro-emulsions.…”