Journal of Environmental Chemical Engineering 7 (2019) 103508
Contents lists available at ScienceDirect
Journal of Environmental Chemical Engineering
journal homepage: www.elsevier.com/locate/jece
Highly efficient and reusable superhydrophobic/superoleophilic
polystyrene@ Fe3O4 nanofiber membrane for high-performance oil/water
separation
T
Sara M. Moatmeda, Mohamed Hamdy Khedra, S.I. El-deka, Hak-Yong Kimb,c,*,
Ahmed G. El-Deend,*
a
Materials Science and Nanotechnology Department, Faculty of Postgraduate Studies for Advanced Sciences (PSAS), Beni-Suef University, Beni-Suef 62511, Egypt
Department of BIN Convergence Technology, Chonbuk National University, Jeonju 561756, South Korea
Department of Organic Materials and Fiber Engineering, Chonbuk National University, Jeonju 561-756, South Korea
d
Renewable Energy Science and Engineering Department, Faculty of Postgraduate Studies for Advanced Sciences (PSAS), Beni-Suef University, Beni-Suef 62511, Egypt
b
c
A R T I C LE I N FO
A B S T R A C T
Keywords:
Superoleophilicity
Hybrid nanofiber membrane
Electrospinning
Oil/water separation
Due to increasing of oil spills and high organic contamination of marine environment, developing of cost-effective and rapid oil/water separation technique has become inevitable. Herein, freestanding and flexible hybrid
polystyrene nanofibers are introduced as highly efficient hybrid membrane for ultrafast oil/water separation
without external pressure. Typically, different loading of Fe3O4 nanoparticles embedded into polystyrene nanofibers using electrospinning to fabricate superhydrophobic/super-oleophilic membrane. The morphological
shape, crystal structure and surface wettability behavior were elucidated by field-emission scanning electron
microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and contact angel,
respectively. The optimum loading of magnetite nanoparticles into the nanofiber membranes was investigated to
achieve best separation performance. The obtained results demonstrated that the incorporation of (Fe3O4) nanoparticles into membrane has a significant impact for enhancing superhydrophobic properties and the separation efficiency against light and heavy oils. Among all formulations, the fabricated (PS@Fe3O410 wt.%)
membrane revealed ultrahigh flux (5000 L m−2 h−1) with separation efficiency of 99.8 % for hexane under
gravity driven process and excellent superhydrophobicity with water contact angle 162° moreover excellent
reusability 98.5 % for 50 consecutive cycles. Interestingly, the proposed hybrid nanofiber membrane achieved
distinct separation efficiencies 95 % and 92 % for food oils such as olive oil and sesame oil. Overall, the current
study provides cost-effective and facile approach to distinctly improve the membrane performance for durable
oil/water separation technique.
1. Introduction
Oil spills poses one of the greatest dilemmas faced the global community. Moreover, industrial oily wastewater contamination resulting
from different factories such as food, dyes, and petrochemical represent
the main reason for many serious diseases [1,2]. In terms of increasing
awareness of marine protection and stringent regulations on industrial
wastewater discharge, development of rapid and efficient oil/water
separation methodologies has become a critical challenge [3–5]. Interestingly, the expulsion of water from fuel oil is very important issue
for safety of engines [6]. Unfortunately, conventional oil separation
methods such as floatation [7], skimming and ultrasonic have some
limitation as high energy consumption, low separation capacity, time
⁎
consuming and secondary waste moreover could not separate oil water
emulsion [8]. However, gravity-driven membrane system (GDM) has
been recently emerged as promising alternatives purification technique
for drinking or rainwater treatment due to no power consumption, low
operation and maintenance cost [9–11].Various type polymers have
been used as membrane materials including Polyacrylonitrile (PAN),
polyvinylidene fluoride (PVDF), polyurethane (PU), polysulfone (PSF)
and Polystyrene (PS) [12–16]. Compared to the utilized polymers, PS is
widely used in containers for food and drinks moreover introduced as
promising membrane materials due to its excellent characteristics such
as cheap, good chemical inertia, high hydraulic stability, easy to handle
and superhydrophobic behaviour [17–19]. To enhance the polymer
membrane performance, various techniques such as chemical
Corresponding authors.
E-mail addresses: khy@jbnu.ac.kr (H.-Y. Kim), ag.eldeen@psas.bsu.edu.eg (A.G. El-Deen).
https://doi.org/10.1016/j.jece.2019.103508
Received 15 September 2019; Received in revised form 26 October 2019; Accepted 29 October 2019
Available online 07 November 2019
2213-3437/ © 2019 Elsevier Ltd. All rights reserved.
Journal of Environmental Chemical Engineering 7 (2019) 103508
S.M. Moatmed, et al.
Fig. 1. Schematic illustration of the superhydrophobic Fe3O4@PS electrospun nanofiber membrane.
steel mesh has been introduced as first time for oil/water separation
within few minutes using syringe pump [41,42]. Jiang et al. prepared
different polymer composite including PAN, PVDF, PS and Fe3O4 as oil
sorbents materials boosted magnetic nanoparticles to enhance the oil
removal capacity and easy collect from the solution after materials
saturated [43,44]. It is worth mentioning that surface coated using
metal oxides or other functionalized group can enhance the oil/water
separation performance [45]. However, the releasing of nanoparticles
form of the surface coated membrane during process distinctly reduce
the performance of membrane [46]. The blending of Fe3O4 NPs with
polymer or spongy support materials not only provide significantly
increase in the separation performance and reusability but also accelerate the diffusion rate of membrane may be attributed to oleophilic
behaviour, excellent adsorption capacity and magnetic features
[47–49].
In this work, a simple strategy is introduced to fabricate robust and
effective PS@Fe3O4 nanofiber membrane for ultrafast gravity driven
oil/water separation. Moreover, the ratio of Fe3O4 nanoparticles in the
composite membrane has been optimized to achieve best separation
efficiency and the highest flux rate. Interestingly, the flux rate and
superhydrophobicity of (PS@Fe3O410%) membrane compared to reported materials in the recent nanocomposite membranes.
Fig. 2. XRD pattern of the Fe3O4 NPs and PS@ Fe3O4 10 wt.% nanofiber mats.
modification [20], surface treatment and blending nanomaterials have
been investigated [21–23]. Recently, numerous nanomaterials embedded into polymeric matrix as silica nanoparticles (NPs), ZnO NPs,
magnetic NPs demonstrated improvement in porosity, permeability and
separation efficiency of membrane [24–27].Besides the chemical composition of membrane, fabrication process has significantly impact on
the membrane characteristics including mechanical properties, porosity
and permeability [28].Consequently, surface roughness and flexibility
play vital role for oil/water separation process, selecting an ideal substrate is also challenge [29,30]. Recently, several oil/water separation
processes have been reported using simple casting method for fabricating thin film membrane or spray coating substrates as stainless-steel
mesh [31,32], copper mesh [33], spongy [34] and cotton [35]. However, these strategies still fare from desirable separation capacity and
reusability. Among various morphological structures, nanofibers (NFs)
have several advantages such as long axial ratio, no agglomeration
behavior, free standing and flexible systems shapeable [36]. Electrospinning technique is a facile, efficient, and robust strategy to fabricate
different fibers-based nanostructure [37,38]. Electrospun nanofiber
membranes have attract great deal of attentions in different applications because of good flexibility properties, high specific surface area
and uniformly porous structure [39,40]. PS nanofiber coated stainless
2. Experimental
2.1. Materials
Polystyrene (PS) (Mw = 192,000), very fine Fe3O4 nanopowder
with ∼50 nm particle size and n-hexane, dimethylformamide (DMF)
(99.8 %) were provided from Sigma–Aldrich. All chemicals and solvents
were used without any further purification.
2.2. Synthesis of polystyrene nanofibrous membrane
20 g of polystyrene was dissolved in 80 mL of DMF and then stirred
for 10 h in water bath at 80 °C to form clear PS solution with 20 %. After
stirring, the solution was loaded in a syringe of 10 mL volume. The
feeding rate of polymer was controlled as 1.2 mL/h using a syringe
pump and the distance between the ground collector and the syringe
needle was fixed at 18 cm with 18 kV. The electrospun nanofiber mats
were collected on aluminum foil and dried overnight under vacuum at
60 °C.
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Journal of Environmental Chemical Engineering 7 (2019) 103508
S.M. Moatmed, et al.
Fig. 3. (a) FESEM image and TEM image (b) of Fe3O4 nanoparticles.
Fig. 4. FESEM images of (a) pristine PS electrospun nanofiber, Fe3O4 intercalated PS nanofibers mats with different ratio (2 %, 5 % and 10 wt.%) and the inset figure
is high magnification of PS @ Fe3O4 10 electrospun mats, (e) the average diameters versus loading Fe3O4 NPs content into PS nanofibers and EDX patterns of PS with
Fe3O4 10 wt.%(f) and the inset is elemental mapping.
3
Journal of Environmental Chemical Engineering 7 (2019) 103508
S.M. Moatmed, et al.
Fig. 5. Optical images of the prepared electrospun nanofibers: (a) pristine PS mat, (b) PS/ Fe3O4 2 %, (c) PS@Fe3O4 5 % and PS@Fe3O410 %(d).
2.3. Synthesis of Fe3O4 intercalated polystyrene nanofibrous hybrid
membrane
Different ratio (2 %, 5 %, 10 wt.%) of Fe3O4 were blended respectively to 10 ml of PS solution and stirred for 2 h. The polymer matrix
solution was transferred to 10 ml of plastic syringe for electrospinning
process under same conditions of pristine PS nanofibers. Fig. 1 displays
schematic diagram for the fabrication process of freestanding hybrid
nanofiber membranes.
2.4. Characterization and measurements
The morphologies structures of the Fe3O4@PS electrospun fiber
mats were characterized using field emission scanning electron microscopy (FE-SEM Hitachi S- 4700, Japan). The phase and crystal structure
were characterized using a PANalytical (Empyrean) X-ray diffraction
with Cu Kα (λ = 1.540°A) radiation, angle range from 10:80° with scan
step of 0.04°. Fourier transform infrared (FTIR) spectra were analyzed
by VERTEX 70/70v spectrometer in the range 400–4000 cm−1. The
surface wettability properties of the proposed nanofiber membranes
were detected using (Ramé-Hart Model 21AC Standard Contact Angle
Fig. 6. FT-IR spectra of different fabricated mats: (a) pure PS NFs, (b) Fe3O4
NPs and PS@ Fe3O4 10 wt.% mats (c).
Fig. 7. Contact angle of PS and PS@Fe3O4 2 %,5 %, and 10 wt.% (a) and optical images of surface wettability behavior for the PS@Fe3O4 10 % water droplets (right)
and commercial oil droplet (left).
4
Journal of Environmental Chemical Engineering 7 (2019) 103508
S.M. Moatmed, et al.
Fig. 8. Optical images of setup oil/water separation process; n-hexane and colorized water using methylene blue.
Fig. 9. Flux efficiency of pure PS and PS@Fe3O4 (2 %,5 % and10 %) composite (a), separation efficiency of different samples (b) and cycling stability of PS@Fe3O4 10
% membrane(c).
cell, and the separation was carried out under gravity without any
pressure. The oil flux efficiency for the proposed nanofibers mats was
recorded and calculated by the following Eq. (1) [50]:
Goniometer/Tensiometer) by sessile-drop technique at room temperature.
2.5. Separation process
Jw =
To setup the oil/water separation cell, the nanofiber mats with
diameter of 10 cm were adjusted between two acrylic cylinders. The
mixture solution was prepared by mixing of two equal volume of 50 mL
oil and water solution then the mixture poured directly into the acrylic
V
A×t
(1)
where Jw (L m−2 h−1) is pristine oil flux, V (L) represents the volume of
passed oil, A (m2) is the effective area of membrane, and t (h) is the
separation time. To evaluate the separation performance for all
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Journal of Environmental Chemical Engineering 7 (2019) 103508
S.M. Moatmed, et al.
3.2. Morphological structure
Fig. 3a and b shows FESEM and TEM images of the Fe3O4 nanoparticles. Obviously, a uniform distribution of ultrafine Fe3O4 sphereslike structure with average particle size of 50 nm. The surface topography and morphology structure for PS electrospun nanofiber and its
composite (PS@Fe3O4 10 wt.%) were presented in Fig. 4. Obviously, all
configuration electrospun nanofibers mats show continuous fiber
structure without beads or cuts. Fig. 4 (b, c and d) depicts the incorporation of different ratio of (2, 5 and 10 wt.%) Fe3O4 nanoparticles
into PS no cracks in nanofibers and uniformly distribution of Fe3O4 NPs
into PS NFs. Furthermore, significant decrease in PS fiber diameters
were detected with increasing of Fe3O4 NPs content where the average
diameters were calculated as 840 nm for pristine PS NFs, 730 nm, 680
and 560 nm for (2, 5 and 10 wt.%) respectively, as shown in Fig. 4(e). It
can be attributed to blending of Fe3O4 with polystyrene solution that
led to increase the rough surface of membrane, enhance the conductivity of polymer matrix and increase carrying charge during electrospinning process consequently elongating the fiber structure to
produce thinner fibers. Fig. 4(e) displays high magnification FE-SEM
image of PS@Fe3O410 wt.%. Surface roughness and porosity of PS NFs
with keeping the backbone structures can be observed. Moreover, energy-dispersive X-ray spectroscopy (EDS) in Fig. 4(F) confirmed the
chemical composition and demonstrated the existence of Fe, and O
elements in the characterized area from the center of the membrane and
the elemental mapping in the inset figure exhibited good and uniformly
distribution of the Fe3O4 NPS into PS NFs.
Fig. 5(a–d) displays the optical images of the introduced electrospun
nanofiber membrane. As shown in Fig. 5 (a), the obtained pristine PS
nanofibers membrane was fluffy as cotton-like structure and can't not
fixed easily based membrane. A darker colored and robust nanofibers
mats were obtained with adding Fe3O4 NPs into PS nanofiber and the
color gradually converted from white to brown color based on Fe3O4
concentration as shown in (Fig. 5).
Fig. 10. Separation efficiency and flux efficiency of PS@Fe3O4 10 wt.% for
different oil-water mixtures.
configuration nanofibers mats, the amount of feed and passed oil after
separation process was recorded and calculated using the following Eq.
(2) [51]:
mp ⎞
γ (%) = ⎜⎛1 −
⎟ × 100
mf ⎠
⎝
(2)
where γ is the separation efficiency, mp and mf present the oil content
in water for the permeate and the feed solution during separation
process.
To investigate the cycling stability of the proposed electrospun nanofiber membranes, the separation process was repeated over 50 cycles.
To confirm the accuracy of the reusability test, the prepared membrane
was dried under vacuum oven at 80 °C for 2 h.
3. Results and discussion
3.1. Characterization
3.3. FTIR spectra of hybrid nanofiber membranes
XRD analysis is very useful technique to determine crystallographic
phases of the prepared materials. Fig. 2 depicts the XRD patterns for the
introduced Fe3O4 NPs and PS@ Fe3O4 nanofiber mats. As shown in this
figure, all characteristic peaks of Fe3O4 NPs at 2θ = 35.665°, 43.33° and
62.88° corresponding to the (311), (400) and (440) reflection planes
according to the (JCPDS No. 19-629) [52]. The PS@Fe3O4 fibrous
composite shows a distinct broad peak related to amorphous polymer
and same characteristic peaks of Fe3O4 indicates uniformly distribution
of nanoparticles in PS nanofibers. Furthermore, the low intensity and
slightly shifted of the diffraction peaks due to amorphous structure of
PS matrix.
Fourier transform infrared spectrometry (FTIR) is widely employed
technique to identify the functional groups. Fig. 6(a) shows characteristics bands of C–H substituted benzenic ring at 758 cm-1 and 690 cm-1,
stretching band of aliphatic saturated C–H at 2850 cm-1, 1610 cm-1 and
1565 cm-1 correspond to CeC bonds of aromatic, and 1158 cm-1 and
1026 cm-1 of aromatic deformation vibration of C–H related to the
chemical composition of pure polystyrene nanofiber mat [53]. Fig. 6(b)
displayed strong characteristic peaks of Fe3O4 at 580 cm−1 can be attributed to the Fe-O vibration from magnetite lattice and Fe-O
stretching vibrations (460–628 cm-1) [54,55]. All characteristic peaks
of PS and Fe3O4 were observed in Fig. 6 (c) reflecting successful
Table 1
Comparison of flux efficiency for different membrane materials recently published.
Materials
Special wettability
Flux (L m−2 h−1)
Contact angle
Ref
PVDF membrane/polyamide
PDMS/PS
Cellular aerogels/ PAN/SiO2
PS nanoporous fibers-based sorbents materials
PVDF/Fe3O4@PS composite nanofibers
Aminated PAN-Ag
PVDF/dopamine-APTES@A-MWCNTs
PVDF/CoFe2O4
PAN/HPEI/PDA
PVDF/DA@TEOS
PVDF/ ZnO
PS@TiO2 (10 wt%)
PS@ ZnO (10 wt%)
PS @Fe3O4 (10 wt%)
Hydrophilic/underwater oleophobic
Superhydrophilic/ superoleophobic
Superhydrophobic/superoleophilic
Oleophilic/hydrophobic
Superhydrophobic/superoleophilic
Superhydrophobic/superoleophilic
Superhydrophilicity–underwater superoleophobic
Superhydrophobic–superoleophilic
Superhydrophilicity–underwater superoleophobicity
Superhydrophilic/underwater superoleophobic
Superhydrophobic/superoleophilic
Superhydrophobic/superoleophilic
Superhydrophobic/superoleophilic
Superhydrophobic/superoleophilic
890
4760
1590
Oil sorption capacity of 113.87 g/g
Oil sorption capacity 35–45
4774.6 ± 45.6
900 under 0.09 MPa
Oil sorption capacity 16.09 g/g
1600
8606 under 0.9 bar
828.95
382
630
5000
148º OCA
162° WCA
162° WCA
NA
128° WCA
171° WCA
153.8º OCA
130.5° WCA
163º OCA
155º OCA
171° WCA
115° WCA
120° WCA
162° WCA
[56]
[57]
[58]
[42]
[43]
[59]
[60]
[61]
[62]
[23]
[63]
This work
This work
This work
6
Journal of Environmental Chemical Engineering 7 (2019) 103508
S.M. Moatmed, et al.
4. Conclusions
intercalating of Fe3O4 NPs into PS nanofibers. The low intensity of
Fe3O4 peaks with little shift can be attributed to blending low amount
of Fe3O4 into the PS@ Fe3O4 nanofiber mats.
In conclusion, ultrafast, standalone and superhydrophobic/superoleophilic PS@Fe3O4 electrospun nanofiber hybrid membranes were
successfully fabricated via one pot strategy of incorporating ultrafine
Fe3O4 nanoparticles into PS electrospun nanofiber using electrospinning. Generally, all PS@Fe3O4 nanofiber composite have high water
contact angle and fast oil diffusion rate compared to pristine PS nanofiber. However, PS@Fe3O4 having 10 wt% achieved excellent separation efficiency of 99.8 % and ultrahigh flux-based gravity driven process of (5000 L m-2 h-1). Furthermore, the prepared PS@Fe3O4 10 wt.%
membrane exhibits flexible, robust and remarkable performance with
excellent reusability of membrane can be achieved over 50 cycles
without any significant decrease. Overall, the proposed study revealed
new avenue for using hybrid polystyrene nanofiber membrane as durable and effective approach which meet the requirements for real separation process on large scale.
3.4. Surface wettability measurements
Contact angle measurements proved to be useful and powerful
technique to characterize the surface wettability behavior. Fig. 7(a)
displays water contact angles (WCA) for the fabricated electrospun
nanofibers membranes. Compared to all formulations, PS@Fe3O4 10 wt.
% composite achieved higher water contact angles. Typically, the water
contact angles were 125°, 127°, 158° and 162° for pure PS, PS@Fe3O4
(2, 5 and 10 wt.%) respectively. This improvement in superhydrophobicity can be attributed to high surface energy and roughness
resulting from Fe3O4 intercalated PS fibers. Optical image in Fig. 7(b)
reflects the surface wettability behavior of the electrospun PS@Fe3O4
10 wt.% mats. Clearly, full rejection of water droplets and completely
penetration of oil droplet with ∼0° oil contact angle (OCA) which
confirmed the superhydrophobic and superoleophilic surface of hydride
PS nanofiber membrane.
Conflict of interests
The authors declare that they have no known competing financial
interests or personal relationships that could have appeared to influence the work reported in this paper.
3.5. Separation performance for the proposed nanofiber membrane
Oil/water separation process were performed using separation setup
system as displayed in Fig. 8 the fabricated neat PS nanofiber and its
composite-based membranes were employed for hexane-water separation. Typically, all proposed electrospun mats were adjusted between
two acrylic cylinders and 50 ml of each solution (hexane and colorized
water using methylene blue) were used in the experiments. The solutions were poured into system under gravity and the flow rate of effluent solution (hexane) was recorded. Fig. 9(a) provides the oil flux for
all proposed membrane configurations. The obtained results revealed
distinct impact of Fe3O4 for increasing separation rate which PS@Fe3O4
10 wt.% achieved flux efficiency (5000 L m-2 h-1) around 10 folds
compared to pristine PS membrane. To achieve higher accuracy in the
separation test, all experiments for the fabricated membranes were
examined three times under same conditions and the average value was
recorded. In addition to the separation efficiency of oil-in-water via
gravity-driven was investigated in Fig. 9(b). clearly, the introduced
membranes revealed very good separation capacity however the PS@
Fe3O4 10 wt.% achieved highest separation efficiency over 99.5 %. Interestingly, ultrafast gravity-driven oil/water separation process was
observed (video S1, Supporting information). The PS@Fe3O4 10 %
performed very fast separation of hexane passed within only 21 s
compared to 2.35 min for neat PS nanofiber membrane.
Cycle lifetime is one of the most requested features to elucidate the
cycling stability and reusability for materials-based membrane. The
reusability test of the prepared PS@Fe3O4 10 wt.% membrane was examined over 50 cycles during membrane process under gravity. As
shown in Fig. 9(c), the PS@Fe3O4 10 wt.% achieved 98.5 % in separation retention over 50 cycles; this finding confirms excellent reusability with durable separation efficiency.
To ensure the applicability and durability of the fabricated nanofiber membrane, different oils densities including n-hexane, petroleum
ether, gasoline oil, olive oil and sesame oil have been applied under
gravity driven separation process. As shown in Fig. 10, The as-prepared
PS@Fe3O4 10 wt.% revealed ultrahigh flux for light oils with excellent
separation efficiency around 99.8 % and even high density of food oils
such as sesame oil, the separation efficiency achieved 92 %. These results elucidated that the PS@Fe3O4 10 wt.% composite nanofiber poses
robust and efficient membrane for multi separation process. The prepared PS@Fe3O4 10 wt.% membrane revealed superior water rejection
and excellent oleophilic behavior with ultrahigh flux rate of 5000 L m2 -1
h compared to other metal oxides including TiO2, ZnO and recent
reported membranes under various operating conditions as summarized
in Table 1.
Appendix A. Supplementary data
Supplementary material related to this article can be found, in the
online version, at doi:https://doi.org/10.1016/j.jece.2019.103508.
References
[1] M. Scheringer, Nanoecotoxicology: environmental risks of nanomaterials, Nat.
Nanotechnol. 3 (2008) 322–323, https://doi.org/10.1038/nnano.2008.145.
[2] E.B. Kujawinski, M.C. Kido Soule, D.L. Valentine, A.K. Boysen, K. Longnecker,
M.C. Redmond, Fate of dispersants associated with the deepwater horizon oil spill,
Environ. Sci. Technol. 45 (2011) 1298–1306, https://doi.org/10.1021/es103838p.
[3] M.O. Adebajo, R.L. Frost, J.T. Kloprogge, O. Carmody, S. Kokot, Porous materials
for oil spill cleanup: a review of synthesis and absorbing properties, J. Porous
Mater. 10 (2003) 159–170, https://doi.org/10.1023/A:1027484117065.
[4] Z. Xue, Y. Cao, N. Liu, L. Feng, L. Jiang, Special wettable materials for oil/water
separation, J. Mater. Chem. A 2 (2014) 2445–2460, https://doi.org/10.1039/
c3ta13397d.
[5] H. Bidgoli, A.A. Khodadadi, Y. Mortazavi, A hydrophobic/oleophilic chitosan-based
sorbent: toward an effective oil spill remediation technology, J. Environ. Chem.
Eng. 7 (2019) 103340, , https://doi.org/10.1016/j.jece.2019.103340.
[6] A. Oasmaa, S. Czernik, Fuel oil quality of biomass pyrolysis oils—state of the art for
the end users, Energy Fuels 13 (1999) 914–921, https://doi.org/10.1021/
ef980272b.
[7] Z. Chu, S. Seeger, Superamphiphobic surfaces, Chem. Soc. Rev. 43 (2014)
2784–2798, https://doi.org/10.1039/c3cs60415b.
[8] Z. Chu, Y. Feng, S. Seeger, Oil/water separation with selective superantiwetting/
superwetting surface materials, Angew. Chem. Int. Ed. 54 (2015) 2328–2338,
https://doi.org/10.1002/anie.201405785.
[9] N. Derlon, N. Koch, B. Eugster, T. Posch, J. Pernthaler, W. Pronk, E. Morgenroth,
Activity of metazoa governs biofilm structure formation and enhances permeate
flux during gravity-driven membrane (GDM) filtration, Water Res. 47 (2013)
2085–2095, https://doi.org/10.1016/j.watres.2013.01.033.
[10] X. Tang, Y. Si, J. Ge, B. Ding, L. Liu, G. Zheng, W. Luo, J. Yu, In situ polymerized
superhydrophobic and superoleophilic nanofibrous membranes for gravity driven
oil–water separation, Nanoscale 5 (2013) 11657–11664, https://doi.org/10.1039/
c3nr03937d.
[11] M.H. Tai, P. Gao, B.Y.L. Tan, D.D. Sun, J.O. Leckie, Highly efficient and flexible
electrospun carbon–silica nanofibrous membrane for ultrafast gravity-driven oil–water separation, ACS Appl. Mater. Interfaces 6 (2014) 9393–9401, https://doi.
org/10.1021/am501758c.
[12] T.A. Saleh, V.K. Gupta, An overview of membrane science and technology,
Nanomater. Polym. Membr. 3 (2016) 1–23, https://doi.org/10.1016/b978-0-12804703-3.00001-2.
[13] Q.L. Gao, F. Fang, C. Chen, X.Y. Zhu, J. Li, H.Y. Tang, Z.B. Zhang, X.J. Huang, A
facile approach to silica-modified polysulfone microfiltration membranes for oil-inwater emulsion separation, RSC Adv. 6 (2016) 41323–41330, https://doi.org/10.
1039/c6ra07929f.
[14] W. Ma, Z. Guo, J. Zhao, Q. Yu, F. Wang, J. Han, H. Pan, J. Yao, Q. Zhang,
S.K. Samal, S.C. De Smedt, C. Huang, Polyimide/cellulose acetate core/shell electrospun fibrous membranes for oil-water separation, Sep. Purif. Technol. 177
(2017) 71–85, https://doi.org/10.1016/j.seppur.2016.12.032.
[15] X. Zhang, Q. Huang, F. Deng, H. Huang, Q. Wan, M. Liu, Y. Wei, Mussel-inspired
fabrication of functional materials and their environmental applications: progress
and prospects, Appl. Mater. Today 7 (2017) 222–238, https://doi.org/10.1016/j.
7
Journal of Environmental Chemical Engineering 7 (2019) 103508
S.M. Moatmed, et al.
[40] J.C. Wang, H. Lou, Z.H. Cui, Y. Hou, Y. Li, Y. Zhang, K. Jiang, W. Shi, L. Qu,
Fabrication of porous polyacrylamide/polystyrene fibrous membranes for efficient
oil–water separation, Sep. Purif. Technol. 222 (2019) 278–283, https://doi.org/10.
1016/j.seppur.2019.04.044.
[41] M.W. Lee, S. An, S.S. Latthe, C. Lee, S. Hong, S.S. Yoon, Electrospun polystyrene
nanofiber membrane with superhydrophobicity and superoleophilicity for selective
separation of water and low viscous oil, ACS Appl. Mater. Interfaces 5 (2013)
10597–10604, https://doi.org/10.1021/am404156k.
[42] J. Lin, Y. Shang, B. Ding, J. Yang, J. Yu, S.S. Al-Deyab, Nanoporous polystyrene
fibers for oil spill cleanup, Mar. Pollut. Bull. 64 (2012) 347–352, https://doi.org/
10.1016/j.marpolbul.2011.11.002.
[43] Z. Jiang, L.D. Tijing, A. Amarjargal, C.H. Park, K.J. An, H.K. Shon, C.S. Kim,
Removal of oil from water using magnetic bicomponent composite nanofibers fabricated by electrospinning, Compos. B Eng. 77 (2015) 311–318, https://doi.org/10.
1016/j.compositesb.2015.03.067.
[44] P.K. Sow, S. Ishita, R. Singhal, Sustainable approach to recycle waste polystyrene to
high-value submicron fibers using solution blow spinning and application towards
oil–water separation, J. Environ. Chem. Eng. (2018), https://doi.org/10.1016/j.
jece.2018.11.031.
[45] M. Padaki, R. Surya Murali, M.S. Abdullah, N. Misdan, A. Moslehyani, M.A. Kassim,
N. Hilal, A.F. Ismail, Membrane technology enhancement in oil–water separation. A
review, Desalination 357 (2015) 197–207, https://doi.org/10.1016/j.desal.2014.
11.023.
[46] R.K. Gupta, G.J. Dunderdale, M.W. England, A. Hozumi, Oil/water separation
techniques: a review of recent progresses and future directions, J. Mater. Chem. A 5
(2017) 16025–16058.
[47] M. Nazhipkyzy, A. Nurgain, M. Florent, A. Policicchio, T.J. Bandosz, Magnetic soot:
surface properties and application to remove oil contamination from water, J.
Environ. Chem. Eng. 7 (2019), https://doi.org/10.1016/j.jece.2019.103074.
[48] L. Wu, L. Li, B. Li, J. Zhang, A. Wang, Magnetic, durable, and superhydrophobic
polyurethane@ Fe3O4@ SiO2@ fluoropolymer sponges for selective oil absorption
and oil/water separation, ACS Appl. Mater. Interfaces 7 (2015) 4936–4946.
[49] Y. Liu, X. Wang, S. Feng, Nonflammable and magnetic sponge decorated with
polydimethylsiloxane brush for multitasking and highly efficient oil–water separation, Adv. Funct. Mater. (2019) 1902488.
[50] Y. Zhao, J. Lu, X. Liu, Y. Wang, J. Lin, N. Peng, J. Li, F. Zhao, Performance enhancement of polyvinyl chloride ultrafiltration membrane modified with graphene
oxide, J. Colloid Interface Sci. 480 (2016) 1–8, https://doi.org/10.1016/j.jcis.2016.
06.075.
[51] Z. Wang, X. Jiang, X. Cheng, C.H. Lau, L. Shao, Mussel-inspired hybrid coatings
that transform membrane hydrophobicity into high hydrophilicity and underwater
superoleophobicity for oil-in-water emulsion separation, ACS Appl. Mater.
Interfaces 7 (2015) 9534–9545, https://doi.org/10.1021/acsami.5b00894.
[52] W. Kim, C.Y. Suh, S.W. Cho, K.M. Roh, H. Kwon, K. Song, I.J. Shon, A new method
for the identification and quantification of magnetite-maghemite mixture using
conventional X-ray diffraction technique, Talanta 94 (2012) 348–352, https://doi.
org/10.1016/j.talanta.2012.03.001.
[53] Z. Jiang, L.D. Tijing, A. Amarjargal, C.H. Park, K.J. An, H.K. Shon, C.S. Kim,
Removal of oil from water using magnetic bicomponent composite nanofibers
fabricated by electrospinning, Compos. B Eng. 77 (2015) 311–318, https://doi.org/
10.1016/j.compositesb.2015.03.067.
[54] S. Yang, T. Zeng, Y. Li, J. Liu, Q. Chen, J. Zhou, Y. Ye, B. Tang, Preparation of
graphene oxide decorated Fe3O4@SiO2 nanocomposites with superior adsorption
capacity and SERS detection for organic dyes, J. Nanomater. 2015 (2015), https://
doi.org/10.1155/2015/817924.
[55] P. Granitzer, K. Rumpf, M. Venkatesan, A.G. Roca, L. Cabrera, M.P. Morales,
P. Poelt, M. Albu, Magnetic study of Fe3O4 nanoparticles incorporated within
mesoporous silicon, J. Electrochem. Soc. 157 (2010) K145–K151, https://doi.org/
10.1149/1.3425605.
[56] R. Lv, M. Yin, W. Zheng, B. Na, B. Wang, H. Liu, Poly(vinylidene fluoride) fibrous
membranes doped with polyamide 6 for highly efficient separation of a stable oil/
water emulsion, J. Appl. Polym. Sci. 134 (2017), https://doi.org/10.1002/app.
44980.
[57] C.-F. Wang, Y.-J. Tsai, S.-W. Kuo, K.-J. Lee, C.-C. Hu, J.-Y. Lai, Toward superhydrophobic/superoleophilic materials for separation of oil/water mixtures and
water-in-oil emulsions using phase inversion methods, Coatings 8 (2018) 396.
[58] Y. Si, Q. Fu, X. Wang, J. Zhu, J. Yu, G. Sun, B. Ding, Superelastic and superhydrophobic nanofiber-assembled cellular aerogels for effective separation of oil/
water emulsions, ACS Nano 9 (2015) 3791–3799, https://doi.org/10.1021/
nn506633b.
[59] Z. Wang, X. Jiang, X. Cheng, C.H. Lau, L. Shao, Mussel-inspired hybrid coatings that
transform membrane hydrophobicity into high hydrophilicity and underwater superoleophobicity for oil-in-water emulsion separation, ACS Appl. Mater. Interfaces
7 (2015) 9534–9545, https://doi.org/10.1021/acsami.5b00894.
[60] X. Yang, Y. He, G. Zeng, X. Chen, H. Shi, D. Qing, F. Li, Q. Chen, Bio-inspired
method for preparation of multiwall carbon nanotubes decorated superhydrophilic
poly(vinylidene fluoride) membrane for oil/water emulsion separation, Chem. Eng.
J. 321 (2017) 245–256, https://doi.org/10.1016/j.cej.2017.03.106.
[61] P.P. Dorneanu, C. Cojocaru, N. Olaru, P. Samoila, A. Airinei, L. Sacarescu,
Electrospun PVDF fibers and a novel PVDF/CoFe2O4 fibrous composite as nanostructured sorbent materials for oil spill cleanup, Appl. Surf. Sci. 424 (2017)
389–396, https://doi.org/10.1016/j.apsusc.2017.01.177.
[62] J. Wang, L. Hou, K. Yan, L. Zhang, Q.J. Yu, Polydopamine nanocluster decorated
electrospun nanofibrous membrane for separation of oil/water emulsions, J.
Membr. Sci. 547 (2018) 156–162, https://doi.org/10.1016/j.memsci.2017.10.028.
[63] X. Zhang, Y. Wang, Y. Liu, J. Xu, Y. Han, X. Xu, Preparation, performances of PVDF/
ZnO hybrid membranes and their applications in the removal of copper ions, Appl.
Surf. Sci. 316 (2014) 333–340, https://doi.org/10.1016/j.apsusc.2014.08.004.
apmt.2017.04.001.
[16] A. Modi, J. Bellare, Efficiently improved oil/water separation using high flux and
superior antifouling polysulfone hollow fiber membranes modified with functionalized carbon nanotubes/graphene oxide nanohybrid, J. Environ. Chem. Eng. 7
(2019) 102944, , https://doi.org/10.1016/j.jece.2019.102944.
[17] X. Wang, J. Yu, G. Sun, B. Ding, Electrospun nanofibrous materials: a versatile
medium for effective oil/water separation, Mater. Today. 19 (2016) 403–414,
https://doi.org/10.1016/j.mattod.2015.11.010.
[18] J. Lin, F. Tian, Y. Shang, F. Wang, B. Ding, J. Yu, Z. Guo, Co-axial electrospun
polystyrene/polyurethane fibres for oil collection from water surface, Nanoscale 5
(2013) 2745–2755, https://doi.org/10.1039/c3nr34008b.
[19] J.C. Wang, H. Lou, Z.H. Cui, Y. Hou, Y. Li, Y. Zhang, K. Jiang, W. Shi, L. Qu,
Fabrication of porous polyacrylamide/polystyrene fibrous membranes for efficient
oil–water separation, Sep. Purif. Technol. (2019) 278–283, https://doi.org/10.
1016/j.seppur.2019.04.044.
[20] Y. Cao, X. Zhang, L. Tao, K. Li, Z. Xue, L. Feng, Y. Wei, Mussel-inspired chemistry
and michael addition reaction for efficient oil/water separation, ACS Appl. Mater.
Interfaces 5 (2013) 4438–4442, https://doi.org/10.1021/am4008598.
[21] G. Zeng, T. Chen, L. Huang, M. Liu, R. Jiang, Q. Wan, Y. Dai, Y. Wen, X. Zhang,
Y. Wei, Surface modification and drug delivery applications of MoS2 nanosheets
with polymers through the combination of mussel inspired chemistry and SET-LRP,
J. Taiwan Inst. Chem. Eng. 82 (2018) 205–213, https://doi.org/10.1016/j.jtice.
2017.08.025.
[22] M.R. Esfahani, S.A. Aktij, Z. Dabaghian, M.D. Firouzjaei, A. Rahimpour, J. Eke,
I.C. Escobar, M. Abolhassani, L.F. Greenlee, A.R. Esfahani, A. Sadmani,
N. Koutahzadeh, Nanocomposite membranes for water separation and purification:
fabrication, modification, and applications, Sep. Purif. Technol. (2019) 465–499,
https://doi.org/10.1016/j.seppur.2018.12.050.
[23] Z. Wang, X. Jiang, X. Cheng, C.H. Lau, L. Shao, Mussel-inspired hybrid coatings that
transform membrane hydrophobicity into high hydrophilicity and underwater superoleophobicity for oil-in-water emulsion separation, ACS Appl. Mater. Interfaces
7 (2015) 9534–9545, https://doi.org/10.1021/acsami.5b00894.
[24] A. Kamgar, S. Hassanajili, G. Karimipourfard, Fe3O4@SiO2@MPS core/shell nanocomposites: the effect of the core weight on their magnetic properties and oil
separation performance, J. Environ. Chem. Eng. 6 (2018) 3034–3040, https://doi.
org/10.1016/j.jece.2018.04.057.
[25] X. Zhang, Y. Wang, Y. Liu, J. Xu, Y. Han, X. Xu, Preparation, performances of PVDF/
ZnO hybrid membranes and their applications in the removal of copper ions, Appl.
Surf. Sci. 316 (2014) 333–340, https://doi.org/10.1016/j.apsusc.2014.08.004.
[26] Q. Huang, M. Liu, L. Mao, D. Xu, G. Zeng, H. Huang, R. Jiang, F. Deng, X. Zhang,
Y. Wei, Surface functionalized SiO2 nanoparticles with cationic polymers via the
combination of mussel inspired chemistry and surface initiated atom transfer radical polymerization: characterization and enhanced removal of organic dye, J.
Colloid Interface Sci. 499 (2017) 170–179, https://doi.org/10.1016/j.jcis.2017.03.
102.
[27] B. Ge, X. Zhu, Y. Li, X. Men, P. Li, Z. Zhang, Versatile fabrication of magnetic superhydrophobic foams and application for oil–water separation, Colloids Surfaces A
Physicochem. Eng. Asp. 482 (2015) 687–692, https://doi.org/10.1016/j.colsurfa.
2015.05.061.
[28] M. Padaki, R. Surya Murali, M.S. Abdullah, N. Misdan, A. Moslehyani, M.A. Kassim,
N. Hilal, A.F. Ismail, Membrane technology enhancement in oil-water separation. A
review, Desalination 357 (2015) 197–207, https://doi.org/10.1016/j.desal.2014.
11.023.
[29] J. Zhang, Y. Shao, C. Te Hsieh, Y.F. Chen, T.C. Su, J.P. Hsu, R.S. Juang, Synthesis of
magnetic iron oxide nanoparticles onto fluorinated carbon fabrics for contaminant
removal and oil–water separation, Sep. Purif. Technol. 174 (2017) 312–319,
https://doi.org/10.1016/j.seppur.2016.11.006.
[30] Z. Xiong, H. Lin, F. Liu, P. Xiao, Z. Wu, T. Li, D. Li, Flexible PVDF membranes with
exceptional robust superwetting surface for continuous separation of oil/water
emulsions, Sci. Rep. 7 (2017) 1–12, https://doi.org/10.1038/s41598-017-14429-2.
[31] M.W. Lee, S. An, S.S. Latthe, C. Lee, S. Hong, S.S. Yoon, Electrospun polystyrene
nanofiber membrane with superhydrophobicity and superoleophilicity for selective
separation of water and low viscous oil, ACS Appl. Mater. Interfaces 5 (2013)
10597–10604, https://doi.org/10.1021/am404156k.
[32] Q. Wen, J. Di, L. Jiang, J. Yu, R. Xu, Zeolite-coated mesh film for efficient oil-water
separation, Chem. Sci. 4 (2013) 591–595, https://doi.org/10.1039/c2sc21772d.
[33] Y. Yang, Z. Ding, L. Liu, Fabrication of super-hydrophobic and super-oleophlic
membranes and their separation of oil-water mixture, Beijing Huagong Daxue
Xuebao (Ziran Kexueban)/J. Beijing Univ. Chem. Technol. (Nat. Sci. Ed.) 40 (2013)
21–25.
[34] B. Wang, J. Li, G. Wang, W. Liang, Y. Zhang, L. Shi, Z. Guo, W. Liu, Methodology for
robust superhydrophobic fabrics and sponges from in situ growth of transition
metal/metal oxide nanocrystals with thiol modification and their applications in
oil/water separation, ACS Appl. Mater. Interfaces 5 (2013) 1827–1839, https://doi.
org/10.1021/am303176a.
[35] X. Zhou, Z. Zhang, X. Xu, F. Guo, X. Zhu, X. Men, B. Ge, Robust and durable superhydrophobic cotton fabrics for oil/water separation, ACS Appl. Mater. Interfaces
5 (2013) 7208–7214, https://doi.org/10.1021/am4015346.
[36] W.E. Teo, R. Inai, S. Ramakrishna, Technological advances in electrospinning of
nanofibers, Sci. Technol. Adv. Mater. 12 (2011) 13002, https://doi.org/10.1088/
1468-6996/12/1/013002.
[37] J. Xue, J. Xie, W. Liu, Y. Xia, Electrospun nanofibers: new concepts, materials, and
applications, Acc. Chem. Res. 50 (2017) 1976–1987.
[38] B. Ding, Y. Si, Electrospun Nanofibers for Energy and Environmental Applications,
Springer, 2011, https://doi.org/10.1039/b809074m.
[39] S. Ramakrishna, K. Fujihara, W.E. Teo, T. Yong, Z. Ma, R. Ramaseshan, Electrospun
nanofibers: solving global issues, Mater. Today. 9 (2006) 40–50, https://doi.org/
10.1016/S1369-7021(06)71389-X.
8