| Abstrakt: |
For satisfying various demands of water-oil emulsions separation, a Janus cellulose nanocomposite membrane has been fabricated in this study. Specifically, the cellulose paper with the superhydrophilic and underwater superoleophobic properties served as the substrate, meanwhile the PVDF/hydrophobic-SiO 2 nanocomposite were successfully assembled to the top of substrate with the adhesion of PU by the technologies of high pressure spraying and electrostatic spinning for obtaining the superhydrophobic and superoleophilic layer. Under the action of gravity, Janus cellulose nanocomposite membrane effectively separated the water-in-oil emulsions when PVDF/hydrophobic-SiO 2 nanocomposite layer (obverse) was on the top, and removed the small oil droplets from its oil-in-water emulsions when the cellulose layer (reverse) was on the top. Notably, the Janus cellulose nanocomposite membrane could complete the selective one-way transmission when the gravity effect was excluded. Moreover, the results of resistance against acid and base, abrasion resistance, filtration efficiency, repeatability, flux, etc. confirmed the remarkable superwetting durability and high selectivity of Janus cellulose nanocomposite membrane towards various emulsions, suggesting its enormous potential in practical water-oil separation. In the study, the superhydrophobic and superoleophilic PVDF/hydrophobic-SiO 2 nanocomposite layer assembled on the superhydrophilic and underwater super- oleophobic cellulose substrate in the presence of PU. The composite layer firmly adhered to the cellulose substrate for achieving Janus membrane by the technologies of high pressure spraying and electrostatic spinning. Under the action of gravity, the Janus membrane efficiently separated water-in-oil (oil-in-water) emulsions when its obverse (reverse) was on the top. Notably, the Janus cellulose membrane could complete the selective one-way transmission when the gravity effect was excluded. Besides, it also showed the good mechanical and chemical stabilities, which offered us a novel and feasible strategy for satisfying various water/oil separation demands. [Display omitted] • PU/PVDF/hydrophobic-SiO 2 composited superhydrophobic and superoleophilic layer on the substrate with opposite wettability. • Nanocomposite layer was adhered to cellulose substrate to get Janus membrane by high pressure spraying and electrospinning. • Under gravity, Janus cellulose membrane can separate various water/oil emulsions when switch its different side on the top. • Without gravity, Janus cellulose membrane can complete desired liquid transmission arising from its asymmetric wettability. • Good mechanical and chemical stabilities proved it a feasible strategy for satisfying various water/oil separation demands. [ABSTRACT FROM AUTHOR] |
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