Poly(ethylene-co-vinyl alcohol) Electrospun Nanofiber Membranes for Gravity-Driven Oil/Water Separation

Abstract

Fabrication of highly efficient oil/water separation membranes is attractive and challenging work for the actual application of the membranes in the treatment of oily wastewater and cleaning up oil spills/oil leakage accidents. In this study, hydrophilic poly(ethylene-co-polyvinyl alcohol) (EVOH) nanofiber membranes were made using an electrospinning technique for oil/water separation. The as-prepared EVOH electrospun nanofiber membranes (ENMs) exhibited a super-hydrophilic property (water contact angle 33.74°) without further treatment. As prepared, ENMs can provide continuous separation of surfactant-free and surfactant-stabilized water-in-oil emulsions with high efficiency (i.e., flux 8200 L m−2 h−1 (LMH), separation efficiency: >99.9%). In addition, their high stability (i.e., reusable, mechanically robust) would broaden the conditions under which they can be employed in the real field oil/water separation applications. Various characterization techniques (including morphology investigation, pore size, porosity, mechanical properties, and performance test) for gravity-driven oil/water separation were employed to evaluate the newly prepared EVOH ENMs.

Superoleophobic Polyketone Nanofiber Membranes for Efficient Separation of Oil/water Emulsions

“…The oil/water separation experiments of the PK nanofiber membranes were then conducted using a dead‐end cell‐model (shown in Figure S10). The separation was achieved via gravity after initially adjusting the oil‐in‐water emulsion solutions at a height of 10 cm (1 KPa or 0.01 bar) [24] . The height was maintained by adding the emulsion feed solution at 1 min intervals (i. e., almost equal pressure during the test).…”

“…The separation was achieved via gravity after initially adjusting the oil-in-water emulsion solutions at a height of 10 cm (1 KPa or 0.01 bar). [24] The height was maintained by adding the emulsion feed solution at 1 min intervals (i. e., almost equal pressure during the test). The flux was then calculated by measuring the average volume (minimum of 3 measurements) of the initial 10 min of the separated liquid, which was applied to Equation (1).…”

An Overview of Recent Progress in Nanofiber Membranes for Oily Wastewater Treatment

“…The oil/water models are categorized into two types, which are the oil/water mixtures and the oil/water emulsions. Gravity-driven filtration [ 86 ] is the most straightforward testing process for oil/water separation. Some researchers have also used dead-end [ 87 ] and cross-flow filtration [ 88 ] methods to perform oil/water separation experiments.…”

“…The flux ( ) is measured as the volume of permeate produced per unit time per unit membrane area [ 86 , 87 , 88 ]: where is the volume of the permeate, is the membrane area and is the duration time to collect the permeate. The flux is determined by the nanofiber membrane properties, such as pore size, porosity and fiber diameter.…”

Zero-Material Cost Production of Soil-Coated Fabrics with Underwater Superoleophobicity for Antifouling Oil/Water Separation

“…Up to now, various membranes with underwater superoleophobicity have been produced through coating of metal oxide [ 10 ], polymers [ 11 ], graphene oxide [ 12 ], and composites [ 13 ] on porous substrates through electrodeposition, hydrothermal reaction, vacuum filtration, and spraying. For example, Song et al prepared a superhydrophilic and underwater superoleophobic membrane based on cotton fabric decorated with TiO 2 nanoparticles and citric acid via a micro-dissolution method [ 14 ].…”