POLYMER
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2021
·
IF 4.43
Zhuofan Qin,Liqiang Yi,Shuoshuo Wang,Lina Wang,Juming Yao,Guocheng Zhu,Jiri Militky,Mohanapriya Venkataramam,Ming Zhang
Phase change fibers (PCFs) as a kind of composite material, the composition and spatial distribution of each phase have a great influence on its thermal and mechanical properties . In this article, PCFs with polyvinylpyrrolidone (PVP), polyvinyl butyral (PVB), and polyacrylonitrile (PAN) as sheath and 30% octadecane kerosene as core were prepared by coaxial electrospinning. It was found that octadecane had the highest supercooling degree when it was encapsulated in PVB. Thus, we used pure octadecane, 30% octadecane of isopropanol, chloroform, and kerosene solutions as core solutions, adjusted the fine structure of octadecane in PVB sheath, and four kinds of PCFs with different octadecane particle size and spacing were prepared. Successfully reduced the supercooling degree of octadecane. To compare the mechanical properties of the four fibers. It was found that the composite fiber obtained by using isopropanol as octadecane solvent had the most comprehensive mechanical performance. To find a universal method to control the distribution structure of phase change materials (PCMs) in fibers by coaxial electrospinning, we used PAN and PVDF as the sheath solution, pure octadecane, 30% octadecane in isopropanol, chloroform, petroleum ether, and kerosene solutions as a core solution to prepare the PCFs. Characterization results and analysis of the properties of solutions showed that only when the viscosity of the core and sheath solution was relatively low, it could obtain the bamboo-like structured fibers. And continuous core-sheath structured fibers could be obtained in two situations. First, the low viscosity of sheath solution and high viscosity of core solution; second, the high viscosity of sheath solution.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
·
IF 8.355
Guanzhou Luo,Lanfang Wen,Kai Yang,XinYing Li,Shouping Xu,Pihui Pi,Xiufang Wen
A robust and durable fluorinated 8-MAPOSS-based superamphiphobic fabric (Fabrics-S-MAPOSS-F) was obtained by in situ grafting of 3-Mercaptopropyltriethoxysilane (MPTES), 8-Methacryl polyhedral oligomeric silsesquioxane (8-MAPOSS) and 2-(perfluorooctyl) ethyl methacrylate (FMA) on a cotton fabric. The micropores and mesopores bonding structure with low surface energy on the as-prepared Fabrics-S-MAPOSS-F can capture air, endowing the fabric antifouling, self-cleaning, dehydration resistance, buoyancy boost, drag reduction performance, as well as good durability after UV irradiation, mechanical damage, 300 °C oven heating for 2 h and separately immersion in acid/base/salty solution, even in 98% H 2 SO 4 for 30 min. The Fabrics-S-MAPOSS-F can float on the surface of water or blended oil effortlessly with loading 18.8 times and 15.6 times its own weight of SiO 2 powder, respectively. Compared to untreated fabric, the Fabrics-S-MAPOSS-F exhibits a sailing velocity boost by nearly 2.5 times in both water and blended oil. The drag reduction rate is as high as ~154.7%. This novel smart Fabrics-S-MAPOSS-F can be considered a promising material in life jacket, special garments, package protection or smart device.
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高影响因子
AIP Advances
·
2019
·Vol. 9
·期 11
·
IF 1.579
Zhang Jianwen,Cao Peng,Cui Zhaoliang,Wang Qian,Fan Fan,Qiu Minghui,Wang Xiaozu,Wang Zhaohui,Wang Yong
Membrane fouling can be efficiently mitigated by the vibration of the piezoelectric membrane stimulated by AC signals, but it is still a challenge to fabricate piezoelectric membranes with great efficiency, low energy-consumption, and no harm to the environment during its preparation. The present work provides a new approach to poly(vinylidene fluoride) (PVDF) membranes with piezoelectric properties by directly poling β-phase PVDF membranes using green diluents, which revealed better piezoelectric properties than poling α-phase PVDF membranes. Basically, absolute β-phase crystals of PVDF membranes were induced over thermally induced phase separation with the addition of Acetyl tributyl citrate (ATBC)/ionic liquid ([BMIM]PF 6 ), which are regarded as green and environment-friendly diluents. To endow the piezoelectric property to the β-phase PVDF membrane, a poling process was necessarily conducted. The effect of the poling process on the membrane structure, morphologies, properties, and performances was investigated. Meanwhile, a vibration test for both of the poled and unpoled membranes was performed in an excitation of the alternating signal. The results demonstrated that the poling process positively endowed the piezoelectric property to the PVDF membranes. The membrane structure, morphologies, and performances of the membranes were also changed to some extent by the poling process. Additionally, filtrations of the poled membrane both with and without electrical signals were carried out to test their antifouling performance on the CaCO 3 suspension system and BSA solution, respectively. It was observed that the stable flux of the membranes notably improved when subjected to an electrical AC signal. Thus, it depicted that the piezoelectric PVDF membrane directly poled from the β-phase possesses a promising antifouling performance due to its high piezoelectric vibration.
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高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Tianlong Yu,Shixiang Lu,Wenguo Xu,Rabah Boukherroub
The development of advanced materials with superwettability has captured much research interest, because of the increasing environmental concerns and technological requirements. In this work, a titanium mesh coated with copper micro/nanostructures was fabricated via chemical immersion and annealing treatment. The resulting mesh surface consists of titanium and copper oxides with special dendritic and island-like micro-nano binary structures and exhibited remarkable superhydrophobic/superoleophilic property. The superhydrophobic/superoleophilic Ti mesh (SSTM) proved to be efficient for the separation of various water-oil mixtures and exhibited an excellent reusability in repeating separation cycles of water-carbon tetrachloride. Moreover, the SSTM sample displayed great icephobic property including ice-over delay and low ice adhesion. The self-cleaning properties of the SSTM sample were demonstrated using simulated chalk powder that can be easily washed off by injecting water droplets. It also exhibited superior stability in air atmosphere or water over months and great durability under a continuous tap-water flow impacting or abrasion test.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2019
·
IF 5.107
Jiuyang Lin,Fang Lin,Riri Liu,Ping Li,Shengqiong Fang,Wenyuan Ye,Shuaifei Zhao
Hydrophobic anti-wetting membranes have many applications, such as oily wastewater treatment via oil/water separation, desalination via membrane distillation, and carbon capture via gas-liquid membrane contactors. Herein, we used a simple and scalable method to fabricate robust superhydrophobic polyvinylidene fluoride (PVDF) based membranes by one-step spray-coating of fluorinated SiO 2 nanoparticles. The prepared PVDF membrane was systematically characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and contact angle measurements. The modified PVDF membrane had excellent superhydrophobicity with an extremely high water contact angle up to 171.8 ± 1.1° and a low sliding angle of 1.69 ± 0.13°, due to the fluorinated close-packed hydrophobic SiO 2 nanoparticles on the surface. The modified PVDF membrane maintained its relatively stable superhydrophobicity under various harsh conditions, i.e., exposure in hot water, NaOH and HCl, ultrasonication and high-speed flushing, indicating the superior robustness and stability. The prepared membrane also exhibited consistent separation efficiencies up to 99.88 ± 0.03% in water-in-oil emulsions, and superior recyclability and durability over 40 cycles. In addition, spray-coating showed its great promise in engineering various superhydrophobic surfaces on different substrates and excellent scalability in fabricating large-size membranes. This study demonstrates a facilely scalable spray-coating method for engineering robust superhydrophobic surfaces and membranes that can be potentially used for various gas, vapor and water/oil separations.
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高影响因子
HYDROMETALLURGY
·
2019
·
IF 3.465
Yongli Li,Zhongwei Zhao
For more than a hundred years, extraction with ethyl ether has been the most used method for synthetizing H 3 PW 12 O 40 . However, the use of ethyl ether as the extraction agent faced many problems, such as strict regulation by public safety and environment authorities, poor operating environment, significant dissolution loss, low yields (approximately 80%), and difficulty in realizing continuous production. To overcome these problems, a new extraction method has been proposed in this paper, which uses 2-octanol as the extraction agent and water as the stripping agent. Under optimal conditions (30% 2-octanol in kerosene, O:A = 1:1, 180 g/L H 2 SO 4 , 20 g/L H 3 PO 4 , 45 °C, and a contact time of 2 min), 90.2% of H 3 PW 12 O 40 contained in the solution was extracted in a single stage; the loaded H 3 PW 12 O 40 could then be stripped completely via 3-stage continuous countercurrent stripping by maintaining O:A = 5:1, 65 °C, and t = 5 min. Finally, the obtained strip liquor, containing more than 550 g/L H 3 PW 12 O 40 , was evaporated to obtain crystals, resulting in an increased recovery rate of 10%.
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高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2019
·
IF 5.589
Cheng Chen,Baoliang Chen
Developing underwater superoleophobic filtration materials with robust stability and excellent anti-oil-fouling performance in harsh environments is desired for high efficiency oil/water separation. In this work, irregular hydrophilic graphene oxide (GO) was adopted as a coating material to modify oxidized copper mesh with desired hierarchical surface roughness and hydrophilic composition through a novel in situ copper ion induced crosslinking method. The combination of microscale copper wires and nanoscale hydrophilic GO sheets endowed the resultant GO coated oxidized copper mesh (GO@CuO) with unique underwater superoleophobicity and excellent anti-oil-fouling property. Moreover, the mesh exhibited excellent stability in corrosive solutions with no apparent variations in wetting properties, indicating its good stability. The as-prepared GO@CuO mesh can be applied to separate oil/water mixtures with high efficiency (>99.49%) and good reusability. Due to the excellent anti-oil-fouling property, high separation efficiency, and good stability, the as-prepared underwater superoleophobic mesh could find broad applications in oil/water separations.
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PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
·
IF 3.131
Zhanglei Zhu,Wanzhong Yin,Bin Yang,Yafeng Fu,Jiwei Xue
Slime contamination is an urgent problem that should be solved in coal flotation. The adverse effects of slime contamination, by which low-ash clean coal is covered by high-ash fine slime and hence cannot be separated through the direct flotation process, have been recognized for the past decades. In this investigation, to reduce slime contamination, the reverse-and-direct flotation process was proposed. Flotation results indicated that, based on the similar ash content, the concentrate yield increased by 7.36% using the reserve-and-direct flotation process compared with the two-steps direct flotation process. XPS (X-ray Photoelectron Spectroscopy) and SEM (Scanning Electron Microscopy) results verified that the reduction of fine clay minerals coating on the surface of clean coal was achieved and hence the flotation performance was improved with the reverse-and direct flotation process. Therefore, it can be arrived that the reverse-and-direct flotation process is a potential and effective separation method to upgrade the flotation performance of fine coking coal.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Zichao Yin,Yuhang Li,Tianwen Song,Mutai Bao,Yiming Li,Jinren Lu,Yang Li
The methods to modify commercially available sponge used for recovering spilled oil and organic solvent from water usually possess the drawbacks of high cost, complicated fabrication procedures and secondary pollution. Herein, a superhydrophobic magnetic melamine sponge (MS) was fabricated via in situ synthesis of Fe 3 O 4 particles and dip coating of Candelilla wax (CW). The facile modification process made a transition of MS from amphipathic nonmagnetic sponge to superhydrophobic magnetic sponge. Owning to the high porosity of MS, hierarchical microstructures of Fe 3 O 4 particles and hydrophobic hydrocarbon chain of CW, the modified MS possesses low bulk density (0.0173 g/mL), excellent absorption capacity (55–104 g/g), remote controllability, high water contact angle (WCA, 158.8°), good hydrophobicity maintenance and durability. The obtained sponge also has the abilities to continuously absorb and collect light oil from water surface assisted by a vacuum pump and to separate heavy oil under water as a filter driven by liquid weight. More importantly, our modification strategy may find a new way to prepare superhydrophobic sponge by extending the coating reagent to a series of plant waxes.
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高影响因子
Environmental Science-Nano
·
2019
·Vol. 6
·期 12
·3699-3711
·
IF 7.704
Wenjing Ma,Mengjie Zhang,Yuansheng Li,Mengmeng Kang,Chaobo Huang,Guodong Fu
One of the most pervasive environmental issues is water contaminated with various oils. Developing an efficient and novel functional membrane for oil/water separation is urgently needed. Herein, a flexible, durable and magnetic pH-responsive F3O4/MA–TiO2/PI electrospun nanofibrous membrane (ENM) was fabricated via an electrospinning and green dip-coating route. Combining the rough hierarchical structure and pH-responsive wettability, the as-prepared hybrid membrane can controllably separate a range of not only heavy oil/water but also light oil/water mixtures by only adjusting the pH of the aqueous medium. Both separations exhibit a large flux and outstanding efficiency for the tested oil/water mixtures even after 20 reuse cycles due to the hierarchical structure and flexibility of the membrane. In addition, the flexibility and magnetism of the membrane make it easily removed with a magnet after the separation of the oil/water mixtures. More importantly, the as-prepared membrane not only has excellent stability towards high temperature, corrosive organic solvent/salt solution immersion, and UV irradiation but also shows great resistance to mechanical abrasion and ultrasonic treatment, and the preparation method is facile, environmentally friendly, and cost-effective. Thus, such a membrane may offer exciting opportunities in the application of oily wastewater treatment and on-demand oil/water separation.
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高影响因子
ADVANCED MATERIALS
·
2018
·Vol. 30
·期 30
·1801870
·
IF 21.95
Zhigao Zhu,Wei Wang,Dianpeng Qi,Yifei Luo,Yuanren Liu,Ying Xu,Fuyi Cui,Ce Wang,Xiaodong Chen
Fouling of polymeric membranes remains a major challenge for long-term operation of oily-water remediation. The common reclamation methods to recycle fouled membranes have the issues of either incomplete degradation of organic pollutants or damage to filter membranes. Here, a calcinable polymer membrane with effective reclamation after fouling is reported, which shows full recovery of the original oil/water separation efficiency. The membrane is made of polysulfonamide/polyacrylonitrile fibers by emulsion electrospinning, followed by hydrothermal decoration of TiO 2 nanoparticles. The bonding structured fibrous membrane displays outstanding thermal stability in air (400 °C), strong acid/alkali resistance (at the pH range from 1 to 13), and robust tensile strength. As a result, the chemically fouled polymeric membrane can be easily reclaimed without decreasing in separation performance and mechanical properties by annealing treatment. As a proof-of-concept, the as-prepared membrane is integrated into a wastewater separation tank, which achieves a high water flux over 3000 L m −2 h −1 and oil rejection efficiency of 99.6% for various oil-in-water emulsions. The presented strategy on membrane fabrication is believed to be an effective remedy for membrane fouling, and should apply in a wider field of filtration industry.
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PubMed
高影响因子
Polymers
·
2018
·Vol. 10
·期 5
·523
·
IF 2.935
Limin Zang,Xuan Qiao,Lei Hu,Chao Yang,Qifan Liu,Chun Wei,Jianhui Qiu,Haodao Mo,Ge Song,Jun Yang,Chanjuan Liu
Two magnetic supports with different morphologies and particle sizes were designed and prepared for cellulase immobilization based on chitosan and industrial by-product magnetic coal fly ash (MCFA). One was prepared by coating chitosan onto spherical MCFA particles to form non-porous MCFA@chitosan gel microcomposites (Support I) with a size of several micrometers, and the other was prepared using the suspension method to form porous MCFA/chitosan gel beads (Support II) with a size of several hundred micrometers. Cellulase was covalent binding to the support by glutaraldehyde activation method. The morphology, structure and magnetic property of immobilized cellulase were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and a vibrating-sample magnetometer. The cellulase loading on Support I was 85.8 mg/g with a relatlvely high activity recovery of 76.6%, but the immobilized cellulase exhibited low thermal stability. The cellulase loading on Support II was 76.8 mg/g with a relative low activity recovery of 51.9%, but the immobilized cellulase showed high thermal stability. Cellulase immobilized on Support I had a glucose productivity of 219.8 mg glucose/g CMC and remained 69.9% of the original after 10 cycles; whereas the glucose productivity was 246.4 mg glucose/g CMC and kept 75.5% of its initial value after 10 repeated uses for Support II immobilized cellulase. The results indicate that the two supports can be used as cheap and effective supports to immobilize enzymes.Keywords:magnetic composites;chitosan;coal fly ash;enzyme immobilization
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高影响因子
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