Article pubs.acs.org/IECR
Bioinspired Hydrogel-Coated Mesh with Superhydrophilicity and Underwater Superoleophobicity for Efficient and Ultrafast Oil/Water Separation in Harsh Environments Takeshi Matsubayashi, Mizuki Tenjimbayashi, Masatsugu Komine, Kengo Manabe, and Seimei Shiratori* Center for Material Design Science, School of Integrated Design Engineering, Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan S Supporting Information *
ABSTRACT: Microstructured calcium alginate (Ca-Alg) hydrogel exhibiting superhydrophilicity and underwater superoleophobicity is prepared for high speed and highly efficient oil/water separation. The fabricated mesh works in highly acidic or basic, salty, and hightemperature environments because of the stability of Ca-Alg. Moreover, nonwoven fabric used as a template for Ca-Alg is capable of separation of an oil-in-water emulsion.
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INTRODUCTION With the rapid development of the petroleum-based industry, there are significant needs for new methods to separate oil and water because of increasing oily wastewater as well as occasional oil spill accidents.1−3 Discharged oil causes environmental and ecological damage, threatening marine life and affecting human health because of the decomposition of oil into harmful chemicals.4,5 Conventional methods like oil fences, centrifugation, and in situ combustion possess the disadvantages of limited separation efficiency, high operation cost, and long processing times.6,7 It is therefore important to develop methods for the extraction of oil and other chemical pollutants and removal of pure water from oil in a highly efficient and cost-effective manner. Separation using special wettability is one of the most promising approaches for effective oil/water separation.8 In this method, surface chemical composition and surface geometry are key factors for achieving opposite wettability to oils and water.9−11 Researchers have been devoted to developing superhydrophobic and superoleophilic materials (called “oilremoving” materials) for oil/water separation. Examples of such materials include nanofiber sheets of fluoride copolymers,12 double-layer TiO2-based meshes,13 or marshmallow-like macroporous gels.14 These materials have demonstrated selective and efficient oil/water separation because only oil and not water is able to permeate them. However, these types of material are easily contaminated by oil because of their intrinsic oleophilicity, which subsequently affects the separation property. In addition, it is difficult to effectively separate oil− water mixtures because a water barrier blocks the gravity-driven filtration process because of the higher density of water compared to that of oils.15 © 2017 American Chemical Society
In an alternative approach that also relies on wettability, Tsuteja et al. have demonstrated oil/water separation membranes with hygroresponsive surfaces using fluorodecyl polyhedral oligomeric silsesquioxane (F-POSS), which shows both superhydrophilicity and superoleophobicity in air and under water.16 This “water-removing” material enables selective separation because its superoleophobicity allows only water to permeate the membrane. Thus, it does not suffer from oil contamination, and there is no water blocking layer. Despite the development of water removing materials, there remain some challenges. In particular, the environmental impact and elaborate synthesis process of fluorinated chemicals prevent a wide range of applications. Recently, inspired by fish scales and the need to overcome the above-mentioned challenges, other types of wettability exhibiting both superhydrophilicity and underwater superoleophobicity have emerged as water-removing, oil/water separating materials.17,18 They are free from oil contamination and exhibit no water blocking barrier because of their underwater superoleophobicity and superhydrophilicity. However, despite the demands for practical uses, efficient separation in complicated environments has proven to be difficult because the materials are easily chemically attacked and degraded by aqueous media such as brine (seawater), high or low pH, and high temperatures.19 Nature offers an inspiration to address these problems. The surface of the seaweed Saccharina japonica is covered with Received: Revised: Accepted: Published: 7080
April 17, 2017 May 26, 2017 May 31, 2017 May 31, 2017 DOI: 10.1021/acs.iecr.7b01619 Ind. Eng. Chem. Res. 2017, 56, 7080−7085
Article
Industrial & Engineering Chemistry Research polysaccharides that exhibit antibiofouling behavior in harsh environments because of their underwater superoleophobicity.20 Inspired by the biological features of this seaweed, we attempt to design a mesh-structured membrane with calcium alginate hydrogel, which shows the close nature of salt-tolerant underwater superoleophobicity, for durable oil/water separation. In addition, calcium alginate is stable in extremely salty, acidic, and alkali environments and under high-temperature conditions, and it is a thermoirreversible and water insoluble gel that is biodegradable and nontoxic.21 Herein, we present a fabrication method for a calcium alginate-coated (Ca-Alg) mesh that exhibits efficient and highspeed oil/water separation driven solely by gravitational force. Ca-Alg mesh shows superhydrophilicity in the air and superoleophobicity underwater. Moreover, the fabricated mesh exhibits effective separation of oil in aqueous solutions of salt, acid, or alkali and in hot water, owing to the chemical stability of calcium alginate hydrogel.
Figure 1. Surface properties of the calcium Ca-Alg mesh. (a) Digital photograph of Ca-Alg mesh and (b) low and (c) high magnification SEM images. (d) EDX data showing the primary elemental constituents of the fabricated mesh. (e) FT-IR spectra of bare polyester mesh (blue), sodium alginate powder (yellow), and Ca-Alg mesh (green).
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RESULTS AND DISCUSSION The fabrication process of Ca-Alg mesh is described in Scheme 1. Hydrophilized polyester mesh substrates were sequentially
of Ca-Alg mesh, whereas the features are absent in the spectrum from the bare mesh (Figure 1e).22 Meanwhile, comparison of the spectrum from the Ca-Alg mesh with that from sodium alginate powder shows that a new peak at 1711 cm−1 (corresponding to stretching vibration of CO of carboxylate) has appeared, and the band due to O−H vibration shifts by 153 cm−1 to a higher wavenumber.23 This shift indicates a decrease in the amount of hydrogen bonding and the formation of cross-links between Ca2+ ions and carboxylate or hydroxyl ions.19 As a result, Ca-Alg mesh shows enhanced tensile strength from 13.9 to 16.4 MPa (Figure S2). The wettability of Ca-Alg mesh is characterized as shown in Figure 2. In air, the fabricated mesh exhibits superhydrophilicity
Scheme 1. Processing of Calcium Alginate-Coated (Ca-Alg) Mesha
Hydrophilized polyester mesh was first dipped into a cationic solution of polyethyleneimine and then into an anionic sodium alginate aqueous solution. Sodium alginate was gelled using Ca2+ ions as a gelling agent to form a hydrogel layer on the mesh substrates. a
dipped into an aqueous solution of cationic polyethyleneimine (PEI) and anionic sodium alginate. The coating process for each occurs via electrostatic interaction. The coated mesh was then dipped into CaCl2 solution to promote the gelation of alginate by Ca2+ ions. Figure 1a shows a photograph of the Ca-Alg mesh, and Figure 1b and Figure 1c show typical scanning electron microscopy (SEM) images at different magnification. Calcium alginate hydrogel is uniformly coated onto mesh fibers, and no hydrogel is observed in the pores of the mesh, which allows free passage of water through the membrane during separation. In the magnified SEM image of one coated mesh fiber (Figure 1c), nanoscale roughness is observed. The major chemical constituents of the Ca-Alg mesh were determined with energy-dispersive X-ray (EDX) spectroscopy as shown in Figure 1d where peaks of C, Ca, Cl, and O are seen. Elemental mapping of Ca, Cl, and O was done, and the maps are shown in Figure S1 in Supportimg Information. The uniform distribution of these elements indicates that calcium alginate is evenly coated onto the mesh substrates. Fourier transform infrared (FT-IR) data show that a new peak at 1590 cm−1 (corresponding to the asymmetric O−C−O stretching vibration) and an absorption band at 3354 cm−1 (corresponding to the O−H stretching vibration) are present in the spectra
Figure 2. Wetting behavior of 10 μL of water and oil droplets on the Ca-Alg mesh. (a) Dynamic water droplet on Ca-Alg mesh showing high speed spreading. (b) Dynamic contact of oil droplet on Ca-Alg mesh to demonstrate underwater low oil adhesiveness. (c) Underwater oil contact angle of bare and Ca-Alg meshes. The inset images are photographs of various oil droplets on bare (left) and Ca-Alg (right) meshes under water. 7081
DOI: 10.1021/acs.iecr.7b01619 Ind. Eng. Chem. Res. 2017, 56, 7080−7085
Article
Industrial & Engineering Chemistry Research (water contact angle of 99.5% on average with various types of oils used in the oil/water mixtures as shown in Figure 3b. The gravity-driven separation fluxes of water through the mesh were obtained by measuring the flowing time of water permeating the valid area of the mesh, as demonstrated in Figure 3c. Flux is an important point for practical oil/water separation because practical situations demand that a large quantity of oil/water mixture be separated in a short time.28 CaAlg mesh exhibits a permeate flux of 7800 L m−2 h−1 solely by gravity. In addition, the mesh shows stable permeate flux with various kinds of oil/water mixtures. In general, “oil-removing” materials have difficulty in high-speed separation of water and high-viscosity oil.29 Meanwhile, Ca-Alg mesh exhibits high separation fluxes without being affected by the kind of oil because the permeate medium is always water. The flux (J) is
inversely proportional to the viscosity of permeating liquid (μ) based on the Hagen−Poiseuille law:28 J=
εr 2ΔP 8μLτ
(2)
where ε is porosity, r the pore radius, ΔP the pressure, L the thickness, and τ the tortuosity (the ratio of the total distance traveled by the water to the thickness L). Furthermore, we investigated the morphological effect of the mesh on separation flux. Four types of polyester mesh with a different pore radii (r) were coated with calcium alginate hydrogel, and the separation flux was measured. As shown in Figure 4, the flux linearly increases (correlation coefficient: 0.990) with the porosity parameter (εr2) up to 46979 L m−2 h−1.
Figure 4. Influence of mesh morphology on separation flux. (a) Four types of polyester meshes with different pore radius (r) and porosity (ε) are prepared as substrates. (b) Separation flux as a function of porous parameter (εr2).
The environmental stability of Ca-Alg mesh was evaluated by measuring the oil (chloroform) contact angle in four different aqueous solutions: 1 M HCl, 1 M NaOH, saturated NaCl, and hot (55 °C) water (Figure S4). The mesh shows underwater superoleophobicity under these various harsh conditions with contact angle larger than 150°. Because of the environmental 7082
DOI: 10.1021/acs.iecr.7b01619 Ind. Eng. Chem. Res. 2017, 56, 7080−7085
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Industrial & Engineering Chemistry Research
with separation efficiency of >99.5%. High flux up to 46 979 L m−2 h−1 allows the mesh to be applied for large-scale separation at high speed driven solely by gravity. Moreover, by using nonwoven fabric as substrates to minimize pore radius, the CaAlg fabric is capable of separation of an oil-in-water emulsion. Economical and environmentally friendly materials and processes based on the easily scalable method of coating meshes and fabrics with Ca-Alg could provide a new perspective for practically solving pollution problems caused by industrial wastewater or oil-spill accidents.
stability and thermoirreversibility of calcium alginate hydrogel, the fabricated mesh exhibits efficient and high-speed oil/water separation even under acidic, alkaline, salty, and hot conditions, indicating its possible use for oil spill accidents in seawater or separation of industrial wastewater (Figure 5a and Figure 5b).
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EXPERIMENTAL SECTION Materials. Polyester meshes were supplied by Clever Co., Ltd. (Toyohashi, Japan), and used as substrates. The fiber diameter is 50 μm, and the pore radius is 30, 55, 105, or 164 μm. A pore radius of 55 μm was typically used. Also used as substrates were melt-blown nonwoven polyester fabric (fiber diameter of ∼4.0 μm) supplied by Bell Polyester Products Inc. (Yamaguchi, Japan). Deionized water with a resistivity higher than 18.2 MΩ purified via a three-stage Millipore Mill-Q Plus 185 system (Academic) was utilized in all experiments. 2Propanol (IPA; Kanto Chemical Co., Inc., Tokyo, Japan), KOH (Junsei Chemical Co., Ltd., Tokyo, Japan), poly(ethyleneimine) (PEI, Mw = 70 000; Wako Pure Chemical Industries, Ltd., Osaka, Japan), sodium alginate (Nacalai Tesque, Inc., Kyoto, Japan), and CaCl2 (Wako Pure Chemical Industries, Ltd., Osaka, Japan) were used for film fabrication. Toluene, chloroform, petroleum ether, and hexadecane were purchased from Kanto Chemical Co., Inc. Sodium hydroxide (NaOH) and hydrochloric acid (HCl) were obtained from Kanto Chemical Co., Inc., Tokyo, Japan. Preparation of Calcium Alginate-Coated (Ca-Alg) Mesh. The original mesh films used as substrates were cleaned by sonication first in KOH solution (4.0 wt % in IPA/water = 2:3) and then in pure water. They were blow-dried in air. Cleaned mesh substrates were first dipped into cationic PEI solution (10 wt %) for 30 s. After blow-drying in air, the mesh films were immersed into anionic sodium alginate solution (0.40 wt %) for 30 s and subsequently gelled in CaCl2 (1 M) for 10 min. Films Characterization. SEM images were taken by field emission scanning electron microscopy (FE-SEM, Miniscope TM3030Plus; Hitachi, Japan) at an accelerating voltage of 10 kV to characterize surface morphologies. Major elemental constituents were confirmed by EDX spectroscopy combined with the SEM technique. The chemical bonds within the mesh films before and after alginate coating were examined by Fourier transform infrared spectroscopy (FT-IR) (ALPHA-T, Bruker, Billerica, MA, USA), and spectra were analyzed based on related studies.22,23 Surface wettability studies were performed using a high-speed camera (HAS-D3, Ditect, Tokyo, Japan) capturing a 10 μL water droplet spreading out at the surfaces of mesh. The underwater oil contact angle was measured using four types of 10 μL oil droplets (toluene, chloroform, petroleum ether, and hexadecane) at room temperature (the number of measurements was 5 for each sample surface and type of oil). The underwater oil contact angle was measured in four different aqueous environments: HCl (1 M), NaOH (1 M), NaCl (saturated), and hot water (55 °C). Optical microscopic images of oil-in-water emulsion were taken by a profile microscope (VF7510, KEYENCE, Osaka, Japan). The stress−strain curves and corresponding tensile strength of mesh or fabric samples were evaluated using the
Figure 5. (a) Separation efficiency and (b) flux under harsh environmental conditions. (c, d) Photographs and optical microscopy images of emulsion (c) before and (d) after separation. (e, f) Schematic of interfacial pressure for (e) oil−water−solid system and (f) water−solid−air system.
We also prepared a Ca-Alg-coated nonwoven fabric to compare its oil/water separation performance with that of the fabricated Ca-Alg mesh (see details in Supporting Information). The Ca-Alg fabric extracts water from an oil-in-water emulsion (Figure 5c and Figure 5d) by the coalescence separation achieved by the porous microfabric.28 On the basis of our understanding of the oil/water separation mechanism of Ca-Alg mesh, we have constructed schematic models showing details of the oil−water interface in an oil− water−solid system and the air−water interface in an air− water−solid system during the separation process. These are illustrated in Figure 5e and Figure 5f (see details in Supporting Information). When an oil/water mixture is poured on the CaAlg mesh, oil is retained on the water layer and cannot penetrate the mesh with an intrusion pressure Δp > 0 (negative capillary effect) owing to its underwater superoleophobicity (Figure 5e).30 At the air−water interface in an air−water−solid system (i.e., bottom side of the mesh), a positive capillary effect (Δp < 0) allows water to penetrate the mesh spontaneously because Ca-Alg mesh shows superhydrophilicity in air (Figure 5f). Therefore, an oil/water mixture can be selectively separated through the Ca-Alg mesh with high separation efficiency.
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CONCLUSION In summary, effective and high-speed oil/water separation membranes were produced using calcium alginate hydrogel, a bioinspired material based on the seaweed Saccharina japonica. Because of underwater superoleophobicity and chemical or thermal stability of calcium alginate, calcium alginate-coated mesh has enabled separation of various oil/water mixtures even in highly acidic, alkaline, salty, and hot aqueous environments 7083
DOI: 10.1021/acs.iecr.7b01619 Ind. Eng. Chem. Res. 2017, 56, 7080−7085
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Industrial & Engineering Chemistry Research Notes
TRAPEZIUM LITE software package (Shimadzu Co., Ltd., Kyoto, Japan). Oil/Water Separation. Four types of oil (toluene, chloroform, petroleum ether, and hexadecane) were used in the oil/water separation experiments by mixing water and oil in (1:3 w/w, 150 g in total). In the practical separation in harsh environment, HCl (1 M), NaOH (1 M), NaCl (saturated), hot water (boiled, ∼95 °C) were separated from oil/water mixture. Alginate-coated mesh was placed in a membrane holder (KGS47; Advantec Co., Saijo, Japan), between a glass cylinder and funnel, and the mixture was poured onto the mesh films. The separation efficiency for the oil−water mixture was calculated by the following equation: woil separation efficiency (%) = × 100 woil + wwater (3)
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS We are grateful to Dr. Koji Fujimoto whose comments and suggestions were greatly valuable throughout our study.
where woil and wwater are the weight of oil and water remaining above the mesh after separation, respectively. The flux (J) was calculated by measuring the volume of water that permeated the Ca-Alg mesh within 1 h using the following equation:
J=
V At
(4)
where V is the volume of permeate (100 mL) collected at time t and A is the area of the mesh in contact with the feed solution (0.0096 m2). Oil-in-water emulsion was prepared by mixing toluene and water in 1:10 w:w and sonicated by ultrasonication (ASU-3M; AS ONE Co., Osaka, Japan, oscillatory frequency of 42 kHz, output power of 80 W) for 30 min.
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ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.iecr.7b01619. Elemental distribution taken by EDX, tensile stress− strain curves, laser microscopic images before and after swelling, oil contact angle in harsh aqueous environments, SEM images of pristine nonwoven fabric, polyester mesh and supplementary discussion (wettability, intrusion pressure, separation of emulsion, comparison with other types of filters) (PDF) Toluene/water separation exhibited by Ca-Alg mesh with pore size of 105 μm (AVI) Separation of oil-in-water emulsion exhibited by Ca-Alg fabric (AVI)
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REFERENCES
(1) Shannon, M. A.; Bohn, P. W.; Elimelech, M.; Georgiadis, J. G.; Marinas, B. J.; Mayes, A. M. Science and Technology for Water Purification in the Coming Decades. Nature 2008, 452, 301−310. (2) Lahann, J. Nanomaterials Clean up. Nat. Nanotechnol. 2008, 3, 320−321. (3) Xue, Z.; Cao, Y.; Liu, N.; Feng, L.; Jiang, L. Special Wettable Materials for Oil/water Separation. J. Mater. Chem. A 2014, 2, 2445− 2460. (4) Yu, Y.; Chen, H.; Liu, Y.; Craig, V. S. J.; Lai, Z. Selective Separation of Oil and Water with Mesh Membranes by Capillarity. Adv. Colloid Interface Sci. 2016, 235, 46−55. (5) Alroy, J. The Shifting Balance of Diversity Among Major Marine Animal Groups. Science 2010, 329, 1191−1194. (6) Ortega, R. A.; Carter, E. S.; Ortega, A. E. Nylon 6, 6 Nonwoven Fabric Separates Oil Contaminates from Oil-in-Water Emulsions. PLoS One 2016, 11, e0158493. (7) Chen, F.; Song, J.; Liu, Z.; Liu, J.; Zheng, H.; Huang, S.; Sun, J.; Xu, W.; Liu, X. Atmospheric Pressure Plasma Functionalized Polymer Mesh: An Environmentally Friendly and Efficient Tool for Oil/Water Separation. ACS Sustainable Chem. Eng. 2016, 4, 6828−6837. (8) Wang, B.; Liang, W.; Guo, Z.; Liu, W. Biomimetic SuperLyophobic and Super-Lyophilic Materials Applied for Oil/water Separation: A New Strategy beyond Nature. Chem. Soc. Rev. 2015, 44, 336−361. (9) Manabe, K.; Matsubayashi, T.; Tenjimbayashi, M.; Moriya, T.; Tsuge, Y.; Kyung, K.; Shiratori, S. Controllable Broadband Optical Transparency and Wettability Switching of Temperature-Activated Solid/Liquid-Infused Nano Fibrous Membranes. ACS Nano 2016, 10, 9387−9396. (10) Wang, L.; Zhao, Y.; Tian, Y.; Jiang, L. A General Strategy for the Separation of Immiscible Organic Liquids by Manipulating the Surface Tensions of Nanofibrous Membranes. Angew. Chem., Int. Ed. 2015, 54, 14732−14737. (11) Li, J.; Yan, L.; Li, H.; Li, W.; Zha, F.; Lei, Z. Underwater Superoleophobic Palygorskite Coated Meshes for Efficient Oil/water Separation. J. Mater. Chem. A 2015, 3, 14696−14702. (12) Tenjimbayashi, M.; Sasaki, K.; Matsubayashi, T.; Abe, J.; Manabe, K.; Nishioka, S.; Shiratori, S. A Biologically Inspired Attachable, Self-Standing Nanofibrous Membrane for Versatile Use in Oil−Water Separation. Nanoscale 2016, 8, 10922−10927. (13) Gao, C.; Sun, Z.; Li, K.; Chen, Y.; Cao, Y.; Zhang, S.; Feng, L. Integrated Oil Separation and Water Purification by a Double-Layer TiO2-Based Mesh. Energy Environ. Sci. 2013, 6, 1147−1151. (14) Hayase, G.; Kanamori, K.; Fukuchi, M.; Kaji, H.; Nakanishi, K. Facile Synthesis of Marshmallow-like Macroporous Gels Usable under Harsh Conditions for the Separation of Oil and Water. Angew. Chem., Int. Ed. 2013, 52, 1986−1989. (15) Zhang, F.; Zhang, W. B.; Shi, Z.; Wang, D.; Jin, J.; Jiang, L. Nanowire-Haired Inorganic Membranes with Superhydrophilicity and Underwater Ultralow Adhesive Superoleophobicity for High-Efficiency Oil/Water Separation. Adv. Mater. 2013, 25, 4192−4198. (16) Kota, A. K.; Kwon, G.; Choi, W.; Mabry, J. M.; Tuteja, A. Hygro-Responsive Membranes for Effective Oil−water Separation. Nat. Commun. 2012, 3, 1025−1028. (17) Luo, Z. Y.; Chen, K. X.; Wang, Y. Q.; Wang, J. H.; Mo, D. C.; Lyu, S. S. Superhydrophilic Nickel Nanoparticles with Core-Shell Structure to Decorate Copper Mesh for Efficient Oil/Water Separation. J. Phys. Chem. C 2016, 120, 12685−12692. (18) Yong, J.; Chen, F.; Yang, Q.; Zhang, D.; Farooq, U.; Du, G.; Hou, X. Bioinspired Underwater Superoleophobic Surface with
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. ORCID
Kengo Manabe: 0000-0002-8601-8003 Seimei Shiratori: 0000-0001-9807-3555 Author Contributions
T. M, M.T., K.M, and S.S. designed the concept of this paper. T.M. and M.K. carried out the experiments. T.M. analyzed the data. T.M. and M.T. wrote the manuscript. All authors discussed the results and reviewed the manuscript. Funding
This work was partially supported by JSPS KAKENHI (Grants JP26420710 and JP16J06070) and the SENTAN Project from the Japan Science and Technology Agency (JST). 7084
DOI: 10.1021/acs.iecr.7b01619 Ind. Eng. Chem. Res. 2017, 56, 7080−7085
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Industrial & Engineering Chemistry Research Ultralow Oil-Adhesion Achieved by Femtosecond Laser Microfabrication. J. Mater. Chem. A 2014, 2, 8790−8795. (19) Fan, J.-B.; Song, Y.; Wang, S.; Meng, J.; Yang, G.; Guo, X.; Feng, L.; Jiang, L. Directly Coating Hydrogel on Filter Paper for Effective Oil−Water Separation in Highly Acidic, Alkaline, and Salty Environment. Adv. Funct. Mater. 2015, 25, 5368−5375. (20) Cai, Y.; Lu, Q.; Guo, X.; Wang, S.; Qiao, J.; Jiang, L. SaltTolerant Superoleophobicity on Alginate Gel Surfaces Inspired by Seaweed (Saccharina Japonica). Adv. Mater. 2015, 27, 4162−4168. (21) Bezbaruah, A. N.; Krajangpan, S.; Chisholm, B. J.; Khan, E.; Elorza Bermudez, J. J. Entrapment of Iron Nanoparticles in Calcium Alginate Beads for Groundwater Remediation Applications. J. Hazard. Mater. 2009, 166, 1339−1343. (22) Manabe, K.; Kyung, K. H.; Shiratori, S. Biocompatible Slippery Fluid-Infused Films Composed of Chitosan and Alginate via Layer-byLayer Self-Assembly and Their Antithrombogenicity. ACS Appl. Mater. Interfaces 2015, 7, 4763−4771. (23) Miao, M.; Zhao, J.; Feng, X.; Cao, Y.; Cao, S.; Zhao, Y.; Ge, X.; Sun, L.; Shi, L.; Fang, J. Fast Fabrication of Transparent and MultiLuminescent TEMPO-Oxidized Nano Fibrillated Cellulose Nanopaper Functionalized with Lanthanide. J. Mater. Chem. C 2015, 3, 2511−2517. (24) Osada, B. Y.; Gong, J. Soft and Wet Materials: Polymer Gels. Adv. Mater. 1998, 10, 827−837. (25) Gao, S.; Sun, J.; Liu, P.; Zhang, F.; Zhang, W.; Yuan, S. A Robust Polyionized Hydrogel with an Unprecedented Underwater Anti-Crude-Oil-Adhesion Property. Adv. Mater. 2016, 28, 5307−5314, DOI: 10.1002/adma.201600417. (26) Tenjimbayashi, M.; Togasawa, R.; Manabe, K.; Matsubayashi, T.; Moriya, T.; Komine, M.; Shiratori, S. Liquid-Infused Smooth Coating with Transparency, Super-Durability, and Extraordinary Hydrophobicity. Adv. Funct. Mater. 2016, 26, 6693−6702. (27) Zhang, E.; Cheng, Z.; Lv, T.; Qian, Y.; Liu, Y. Anti-Corrosive Hierarchical Structured Copper Mesh Film with Superhydrophilicity and Underwater Low Adhesive Superoleophobicity for Highly Efficient Oil−Water Separation. J. Mater. Chem. A 2015, 3, 13411− 13417. (28) Si, Y.; Fu, Q.; Wang, X.; Zhu, J.; Yu, J.; Sun, G.; Ding, B. Superelastic and Superhydrophobic Nanofiber-Assembled Cellular Aerogels for Effective Separation of Oil/Water Emulsions. ACS Nano 2015, 9, 3791−3799. (29) Zhou, K.; Zhang, Q. G.; Li, H. M.; Guo, N. N.; Zhu, A. M.; Liu, Q. L. Ultrathin Cellulose Nanosheet Membranes for Superfast Separation of Oil-in-Water. Nanoscale 2014, 6, 10363−10369. (30) Xue, Z.; Wang, S.; Lin, L.; Chen, L.; Liu, M.; Feng, L.; Jiang, L. A Novel Superhydrophilic and Underwater Superoleophobic Hydrogel-Coated Mesh for Oil/Water Separation. Adv. Mater. 2011, 23, 4270−4273.
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