Hierarchical selective membranes combining carbonaceous nanoparticles and commercial permeable substrates for oil/water separation

TRUPP, FEDERICO; TORASSO, NICOLÁS; GRONDONA, DIANA; RUBIOLO, GERARDO H.; GOYANES, SILVIA

SEPARATION AND PURIFICATION TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019 vol. 234

1383-5866

Developing a simple and scalable method to create effective oil?water separation membranes and achievingoptimal trade-off between its permeability and selectivity are current challenges in membrane technology for oilfrom water recovery. Herein, new highly hydrophobic/superoleophilic membranes (contact angles of ~143°/~0°) which meet these challenges have been obtained via a one-step process. Metallic meshes, polypropylenenon-woven and cotton fabrics were exposed to low power RF-plasma of commercial grade acetylene at roomtemperature and medium vacuum. This way, plasma polymerized nanoparticles (NPs) were deposited over thesubstrates. The as-obtained membranes completely prevent the passage of water while allowing a maximum oilflux over 10,000 Lm−2h−1 at 116 Pa, achieving an efficiency above 99% and reusability maintaining highperformance. By controlling the mass surface density of the NPs deposit, it is possible to change both themembranes water breakthrough pressure and oil permeation speed. Membrane permeabilities were successfullyobtained by fitting permeated oil volume vs time data with a Darcy-based model. The influence of surfacedensity of NPs on the permeability and water pressure resistance was described with empirical equations. Fromthe combination of these mathematical relations it is possible to design membranes with optimal trade-off betweenwater pressure resistance and oil permeation speed according to the usage conditions.