Journal of Materials Chemistry A
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2021
·Vol. 10
·期 2
·829-845
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IF 12.732
Ting Ying,Jiafei Su,Yijing Jiang,Lingyu Ni,Xin Jiang,Qinfei Ke,He Xu
Emulsified oily wastewater from dye production chemical plants is one of the most serious components of wastewater treatment. To develop an effective strategy that can not only efficiently separate the emulsified oily wastewater but also do an effective treatment of cationic dye pollutants in water simultaneously before discharging is still a significant challenge. In this work, a kind of hierarchically micro-patterned porous nanofibrous membrane with superhydrophobic metal–organic frameworks (MOFs) incorporated (SMOFs@PT) was successfully prepared for the efficient separation of the emulsified oily wastewater and cationic dye adsorption. The results exhibited that the fabricated membranes possessed micro-patterned structures, and the elliptical pores on the fibers were evenly distributed, while there were superhydrophobic MOFs (SMOFs) embedded in the fibers. Based on the existence of SMOFs, the hydrophobicity of the as-prepared membranes was steadily improved. Not only that, during the treatment of emulsified oily wastewater, the membranes exhibited a stable and excellent separation efficiency (98% or above), and the flux was significantly improved, which was nearly 2–3 times than that of the membranes without SMOFs. Moreover, due to the electronegativity of the SMOFs and the strong capillary force caused by the highly developed pore structure as well as the high specific surface area of the fibers, the membranes can effectively adsorb the cationic organic dyes (from 20 mg L−1 to 2.5 mg L−1 or even lower in 12 h). All these attractive characteristics demonstrated that the SMOFs@PT have promising application prospects in the treatment of emulsified oily wastewater and cationic dye wastewater.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2021
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IF 8.128
Chengyu Sun,Kun Chen,Bernard Wiafe Biney,Kunyin Wang,He Liu,Aijun Guo,Wei Xia
Hypothesis Polyurethane plastic waste (PUPW), a port-abundant solid waste, is difficult to degrade naturally and poses a severe threat to the environment. Hence, the effective recycling of PUPW remains a challenge. Experiments Herein, a strategy of converting PUPW into stacked oil/water filtration layer grain through a layer-by-layer (LBL) assembly process is investigated. Notably, such PU-based, grain-stacked, and switchable wettability of the oil/water filter layer is first reported. Findings The grain-stacked filter layers are flexible for separating immiscible oil/water mixtures, water-in-oil emulsions (WOE), and oil-in-water emulsions (OWE) under gravity over 10 cycle-usages. They can withstand strong acid/alkali solutions (pH = 1–14) and salt solutions over 12 h. Besides, 100-times scale-up experiments have indicated that the obtained filter layers exhibit an upper to 98.2 % separation efficiency for 10 L real industrial oil/water emulsion in the 24 h continuous operation. The demulsification mechanism for emulsions is that the electrostatic interaction along with adsorption between emulsion droplets and grains leads to the uneven distribution of surfactants on the interface film of the emulsion droplets, increasing the probability of tiny droplets colliding and coalescing into large droplets to achieve oil/water separation. This work proposes an effective and economical method of abundant plastic waste for industrial-scale oil–water separation rather than just on the laboratory-scale.
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PubMed
高影响因子
Small
·
2021
·Vol. 18
·期 5
·2105198
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IF 13.281
Xiangyi Zhang,Lipei Ren,Jie Xu,Bin Shang,Xin Liu,Weilin Xu
Structural design of the solar-absorbing layer has been considered as one of the most direct and effective approaches for improving the solar steam generation performance by maximizing the absorption of sunlight, but great challenges in manipulation simplification and structure controllability still remain. Herein, a polyester (PET) fabric covered with a vertically aligned 3D tower-like ferrosoferric oxide (Fe 3 O 4 ) array via a convenient magnetically driven spray-coating method is reported, and both the spatial density and height of the Fe 3 O 4 array are tunable upon spraying time. It shows an extremely high solar absorbance (98.6%) in the entire solar spectrum, which is superior to the corresponding 2D Fe 3 O 4 structure (91.1%). Combining the obtained 3D Fe 3 O 4 /PET with a yolk-shell hydrophobic/superhydrophilic modified melamine-formaldehyde (mMF) sponge, the carefully designed and fabricated 3D Fe 3 O 4 /PET-mMF evaporator can realize a high water evaporation rate of 1.59 kg m −2 h −1 under 1 kW m −2 solar illumination, outperforming most related solar steam generation systems. With the advantages of cost-effectiveness, high evaporation rate, reliable endurance, and structural controllability, this 3D structural design provides an avenue to build up high-performance solar energy-driven water steam generation systems.
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JOURNAL OF MEMBRANE SCIENCE
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2021
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IF 8.742
Longzhu Zheng,Hongqiang Li,Xuejun Lai,Wei Huang,Zengyue Lin,Xingrong Zeng
With the increasing environmental pollution caused by oily wastewater and oil spill accidents, many superwettable materials have been prepared and applied for the separation of oil-water mixtures. However, the fabrication of superwettable materials for multifunctional water purification including oil-in-water and water-in-oil emulsion separation, dyes degradation and heavy metal ions removal still remains challenging. Herein, we propose a facile method to fabricate a superwettable Janus nylon membrane through in situ generation of silver (Ag) particles immobilized by polydopamine and asymmetric chemical modification with dodecanethiol (NDM) and l -cysteine (L-cys) on the positive and negative surfaces, respectively. The positive surface modified by NDM exhibited superhydrophobicity and superoleophilicity, and the negative surface chemically bonded with L-cys possessed opposite wettability with superhydrophilicity and underwater superoleophobicity. The positive and negative surfaces of the Janus membrane were respectively applied for the separations of water-in-oil emulsions and oil-in-water emulsions, and the separation efficiencies all reached above 99%, also demonstrating great reusability and wide adaptability. In addition, the Janus membrane presented not only outstanding performance of degrading methylene blue (MB) with high efficiency above 97.3%, but also excellent capability of absorbing heavy metal ions in the process of emulsion separation. The fabrication processes are facile, mild, and no special equipment is involved, and our findings conceivably provided a new strategy to fabricate superwettable Janus membrane for multifunctional emulsion separation and wastewater purification.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Zhipeng Yang,Hongqiang Li,Chengkai Li,Xuejun Lai,Xingrong Zeng
The fabrication of piezoresistive pressure sensor with self-healing function has attracted worldwide attention for its great prospects in intelligent robots, remote health monitoring and electronic skin. In this work, a conductive and self-healable elastomer (CSE) film with ridge-like microstructure was designed for flexible piezoresistive pressure sensor. Firstly, self-healable polydimethylsiloxane (PDMS)-based elastomer with ureido and imine groups was synthesized via a simple one-pot two-step polycondensation reaction with aminopropyl-terminated PDMS, isophorone diisocyanate and 1, 3, 5-triformylbenzene as monomers. Secondly, the synthesized PDMS-based elastomer solution was casted onto a sandpaper pre-sprayed with ureido pyrimidinone grafted carbon nanotubes/polyurea mixed solution, and the CSE film was obtained after drying and peeling off from the sandpaper. The piezoresistive pressure sensor fabricated with two single-electrode CSE films exhibited high sensitivity of 8.7 kPa −1 (0–6.1 kPa), low detection limit (50 Pa), fast response capability (response/relaxation time of 40/117 ms) and repeatability for 10,000 loading–unloading tests. Moreover, the sensor was able to fully recover to normal work after healing for 36 h at room temperature or even 200 s under the irradiation of near infrared (NIR) light. Importantly, the sensor was successfully applied for not only detecting human motions including radial pulse, speech recognitions and joint movements but also monitoring health status wirelessly through Bluetooth transmission. Our findings put forward a novel method to fabricate a high-performance self-healable piezoresistive sensor for wearable electronics, healthcare monitoring and electronic skin.
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高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 12
·3434
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IF 5.076
Haodong Zhao,Yali He,Zhihua Wang,Yanbao Zhao,Lei Sun
Emulsified oily wastewater threatens human health seriously, and traditional technologies are unable to separate emulsion containing small sized oil droplets. Currently, oil–water emulsions are usually separated by special wettability membranes, and researchers are devoted to developing membranes with excellent antifouling performance and high permeability. Herein, a novel, simple and low-cost method has been proposed for the separation of emulsion containing surfactants. Polyacrylonitrile (PAN) nanofibers were prepared via electrospinning and then coated by polydopamine (PDA) by using self-polymerization reactions in aqueous solutions. The morphology, structure and oil-in-water emulsion separation properties of the as-prepared PDA@PAN nanofibrous membrane were tested. The results show that PDA@PAN nanofibrous membrane has superhydrophilicity and almost no adhesion to crude oil in water, which exhibits excellent oil–water separation ability. The permeability and separation efficiency of n-hexane/water emulsion are up to 1570 Lm−2h−1bar−1and 96.1%, respectively. Furthermore, after 10 cycles of separation, the permeability and separation efficiency values do not decrease significantly, indicating its good recycling performance. This research develops a new method for preparing oil–water separation membrane, which can be used for efficient oil-in-water emulsion separation.Keywords:polyacrylonitrile;electrospinning;nanofibrous membrane;emulsion separation
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Ruilin Su,Ling Yu,Liangzhong Li,Da Chen,Hai Liu,Xiaoyun Fan,Guoqiang Liu,Ruixue Ma,Kun An,Yang Yu
Janus membrane (JM) with asymmetric surface wettability on opposite two surfaces has demonstrated high application potential on the oil/water separation process due to its unique unidirectional water permeation property. In this study, a novel Janus membrane was prepared by electrospinning a thin layer of silica nanoparticle doped poly(vinylidene fluoride- co -hexafluoropropylene) nanofibers (PVDF-HFP/SiO 2 ) on the surface of superhydrophilic polyamine (PDA) coated Cu@Cu(OH) 2 mesh. The thickness and compactness of the nanofiber layer could be controlled by varying the electrospinning time, in which the water contact angle (WCA) value of the hydrophobic layer and critical water breakthrough column height of the membrane were able to be optimized. The Janus membrane (JM-5) with the electrospinning time of 5 min exhibited a large WCA difference of approximately 140°, achieving a spontaneous water permeation from the hydrophobic to hydrophilic direction but blocking the water flow in the reverse direction. The water flux of JM-5 membrane was estimated as 5305 L/m 2. h only under the Laplace pressure. There is no obvious change in the WCA value of the JM-5 membrane observed when the membrane was employed in high saline solutions with a wide pH range of 1–13. The JM-5 membrane could maintain a stable water flux during the 6-cycle oil/water separation process. Such Janus membrane with the function of water diode could be potentially applied for the treatment of oily wastewater and other application fields, e.g., the water removal from oil-type solutions in chemical industry.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2021
·
IF 8.742
Yuanyuan Zhao,Yanqiu Zhang,Feiran Li,Yongping Bai,Yunlu Pan,Jun Ma,Sui Zhang,Lu Shao
Superhydrophilic and underwater superoleophobic (SHL&UWSOB) membranes possess unique advantages in treating oily wastewater. The hydrophilic surface coating and the hierarchical microstructure is significant for the fabrication of SHL&UWSOB membrane, however, the stability of the surface coating remain challenging. In this study, the hydrophilic hierarchical structure was first constructed based on amino-functionalized polyhedral oligosiloxane/proanthocyanidins (POSS-NH 2 /PC) surface coating. Then metal-phenol networks (MPN) was quickly derived from Fe (Ⅲ) and PC networks (FPN). The coordination complex networks formed by POSS-NH 2 /PC cross-linking and FPN synergy construct a hydrophilic hierarchical hybrid layer on poly (vinylidene fluoride) (PVDF) microfiltration (MF) membrane surface. Physicochemical characterizations demonstrate that FPN can greatly restrain the oxidation of phenolic hydroxyl group and reduce the electrostatic repulsion force and enhance the interaction between chain segments, hence, the stability of the coating in strong acidic or alkaline conditions was achieved. The synthesized membrane shows robust superhydrophilicity and underwater superoleophobicity, revealing high efficiency for separation of oil-in-water emulsion in harsh environment, and the oil rejections are over 99.0%. In addition, the resulted membrane has good anti-oil fouling performance even after three-cycles of oil/water separation. The designed membrane lights new prospects in the design of the facile and universality for other superwetting materials.
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Polymer Chemistry
·
2021
·Vol. 12
·期 18
·2722-2730
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IF 5.582
Tianai Tang,Kai Tu,Xiang Xu,Jian Xie,Duo Zhang,Zexin Zhang,Lifen Zhang,Zhenping Cheng
The design and fabrication of micron-size Janus particles (JPs) with new structures and properties are still great challenges although various methods have been used to synthesize nano-size JPs. Therefore, it is of great significance to develop a high-efficiency preparation and facile functionalization technology for micron-size JPs. Herein, we developed a facile one-pot suspension polymerization to synthesize micron-size JPs which can be easily further functionalized for the first time. The key of this method is to use an amphiphilic block copolymer prepared by atom transfer radical polymerization (ATRP) as the macromolecular surfactant (MS). On the one hand, within a certain hydrophile–lipophile balance (HLB) range, the reversed micelles in the oil phase were used to absorb water and expand, then aggregate and fuse, and finally phase separate from the oil phase to form JPs. On the other hand, the MS prepared by ATRP has an initiating group at the MS chain end, which is exposed on one side on the surface of the JPs, so that the facile functionalization of the JPs can be further realized by the ATRP strategy.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
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2021
·Vol. 56
·期 19
·11266-11277
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IF 4.22
Zeng Qingtao,Ma Piming,Lai Dehui,Lai Xuejun,Zeng Xingrong,Li Hongqiang
Abstract In recent years, eco-friendly superhydrophobic materials have aroused much attention. Herein, biodegradable poly(lactic acid) (PLA) was selected as basic material to fabricate superhydrophobic foam with electrothermal effect by dip-coating graphene oxide (GO) on the surface of PLA foam constructed through freeze-drying process and the subsequent reduction with hydroiodic acid. Owing to the micro-nano rough structure of pristine PLA foam and the coverage of low-surface-energy reduced GO (rGO), the obtained rGO@PLA foam exhibited excellent water repellency with a high water contact angle of 150.6°. The foam was able to separate different oil–water mixtures, and the separation efficiencies were all above 96%. Importantly, the rGO layer also endowed the PLA foam with electrothermal conversion capability, and the surface temperature of the rGO@PLA foam rapidly increased to 129.5 °C from 30.8 °C at a low voltage of 15 V within only 120 s. By means of the generated Joule heat, the rGO@PLA foam was successfully applied for separating viscous crude oil from water, and the separation rate was about 14 times higher than that without voltage. Our findings conceivably stand out as a new tool to fabricate functional biodegradable materials for clean-up of viscous crude oil. Graphical abstract
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SEPARATION AND PURIFICATION TECHNOLOGY
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2021
·
IF 7.312
Chengjiang Zuo,Lingbao Wang,Yujia Tong,Lijian Shi,Wenlong Ding,Weixing Li
Poly(vinylidene fluoride) (PVDF) has been widely used in the field of water treatment due to its outstanding chemical tolerance and excellent mechanical strength. However, PVDF membrane often suffers from oil fouling and low flux for separating oil/water emulsions because of low surface energy and strong hydrophobicity. In this work, we propose a bio-inspired biomimetic hydrophilic coating design strategy, in which pyrogallol (PG) and polyethyleneimine (PEI) are used as reactants, and NaIO 4 (SP) is used as an oxidant to modify PVDF microfiltration membrane. This strategy realized the conversion of PVDF membrane surface wettability from hydrophobic to superhydrophilic. The membrane structures and performances were investigated by SEM, FT-IR/ATR, XPS, PMI, water contact angle, pure water permeability and oil rejection for toluene-in-water emulsion. The experimental results showed that the membranes deposited with a PG/PEI mass ratio of 1:1 exhibited the best hydrophilicity and water permeation flux. PVDF-PG/PEI-0.2/0.2 was used to treat surfactant-stabilized toluene-in-water emulsion with the highest flux of 1053 L·m −2 ·h −1 at 0.1 bar and the oil rejection of 98.3%. Moreover, the flux could be wholly restored after simple washing, indicating that the modified PVDF membrane possessed good reusability. Due to the robust adhesion of PG/PEI composite coatings, the proposed strategy for preparing hydrophilic coatings holds significant potentials in the hydrophilic modification of polymer membranes.
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高影响因子
CELLULOSE
·
2021
·Vol. 28
·期 11
·7373-7388
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IF 5.044
Gao Shan,Li Hongqiang,Zheng Longzhu,Huang Wei,Chen Baodeng,Lai Xuejun,Zeng Xingrong
Superhydrophobic materials with special functions of electrical conductivity, magnetism, photothermal conversion and others have been paid considerable attention in the emerging fields including wearable electronics, long-distance manipulation and seawater desalination. Herein, we report a facile approach to fabricate superhydrophobic and conductive cotton fabric (CF) for piezoresistive pressure sensor. It was based on the utilization of the reduced graphene oxide (rGO) layer on CF to form conductive pathways. Meanwhile, the in-situ generated hybrid of polydimethylsiloxane (PDMS)/titanium dioxide (TiO 2 ) on rGO layer through the hydrolysis-condensation and cross-linking reactions between dihydroxyl-terminated PDMS and tetrabutyl titanate played the role of constructing rough structure and decreasing surface energy. The fabricated PDMS/TiO 2 @rGO coated CF exhibited a high water contact angle of 159.3° and possessed outstanding self-cleaning ability. Interestingly, owing to the existence of TiO 2 , the CF also had the capability to degrade organic contaminations and the degradation rate reached 96.4% after being exposed under UV light for 90 min. In addition, the PDMS/TiO 2 @rGO coated CF with a low electrical surface resistance of 0.76 kΩ cm −1 was utilized to design and prepare a multilayer piezoresistive pressure sensor by means of the large number of air gaps between the fibers and the increase of contact points under external pressure. The sensor showed high sensitivity, fast response and good repeatability, and was successfully applied for detecting different human behaviors including pulse, voice recognition, and body motion. Our findings conceivably stand out as a new methodology to fabricate functional superhydrophobic materials and surfaces for practical applications in the fields of electronic skin, human healthcare, interactive wearable device and smart robotics. Graphic abstract
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高影响因子
危险品化学品经营许可证（带存储）