ANALYTICA CHIMICA ACTA
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2018
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IF 5.123
Feng Tan,Xiao Jiang,Xianliang Qiao,Daming Sun,Jinsuo Gao,Xie Quan,Jingwen Chen,Suyu Ren,Yi Wang
A diffusive gradients in thin films (DGT) method using a new high-capacity cerium oxide (CeO 2 ) binding gel, for the first time, was developed for measuring dissolved inorganic arsenic in freshwater and seawater . The capacities of the new CeO 2 binding gel were 682 μg and 375 μg for As III and As V , respectively. The masses of As III and As V accumulated by CeO 2 -DGT device increased linearly with time and agreed well with the theoretical value calculated by DGT equation. The arsenic accumulation by CeO 2 -DGT was independent of pH (4.05–9.04) and ionic strength (0.1–750 mM), and common anions including CO 3 2− , SO 4 2− , Cl − and PO 4 3− had no obvious interference. CeO 2 -DGT showed excellent long-term deployment performance in freshwater and synthetic seawater . Field trials with CeO 2 -DGT achieved successfully the time-weighted-average concentrations of total inorganic arsenic in reservoir water (1.38 ± 0.09 μg/L) and coastal seawater (0.45 ± 0.06 μg/L). The results were comparable to those measured by grab sampling. The proposed method was reliable and robust for in-situ measurements of dissolved inorganic arsenic in environmental waters.
研究领域:
环境化学
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分析化学
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水环境监测
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环境地球化学
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污染生态学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2019
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IF 4.784
Shaojie Zhang,Chao Yu,Na Liu,Yun Teng,Cuiyu Yin
In this study, cellulose pulp and urea were used to synthesize cellulose carbamate (nitrogen content reaches 4.5%) by low-cost and environmentally friendly solid-liquid phase method. Cellulose carbamate fluid was prepared by using sodium hydroxide aqueous solution as solvent. The fluid was regenerated and formed in a coagulation bath , and finally a regenerated cellulose membrane with high transparency and separation ability was obtained. The simple chemical treatment of cellulose not only greatly increased the mass fraction of cellulose dissolution (It has reached 15%) and retains the original crystal form and thermal stability of cellulose. The surface of the membrane was relatively dense, and the inside has regular microchannel . The factors affect the transparency and water flux of regenerated cellulose membranes were discussed by orthogonal experimental range analysis. The ability of the regenerated cellulose membrane to reject dyes was tested. The results showed that the rejection of methyl blue and congo red reached 100%, and the rejection rate of methyl orange reached 60%. The oil/water separation ability and the anti-pollution ability of the regenerated cellulose membrane were tested. The oil/water separation effect reached 100%. This membrane may have application prospect in water treatment, biotechnology.
研究领域:
材料科学
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环境工程
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膜技术
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高分子化学
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水处理
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2023
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IF 5.2
Lei Wu,Mengmeng Zhao,Qiuyan Ye,Xian Xin,Kun Zhang,Yongnan Chen,Ziwei Wang
Electrochemical synthesis of polymer/MOF composite membranes holds great potential for practical applications, yet the preparation of flexible and dense MOF layers remains a challenge, which is crucial for achieving practicality. Herein, a novel ultra-flexible polyethersulfone (PES)/Cu-based metal–organic framework (HKUST-1) composite membrane has been fabricated via an electrochemical synthesis method. Various reaction conditions, including voltage, stirring speed, and reaction time, were systematically investigated to elucidate their influence on crystal growth and the resulting membrane uniformity. The characterization results showed that high voltage and moderate stirring as well as are conducive to obtaining uniform fine crystals. Additionally, a relatively extended reaction time is advantageous for achieving a more continuous and denser MOFs membrane with outstanding flexibility. The optimized membrane possesses an excellent separation flux (2.81 × 10 3 ±32 L m −2 h −1 ·bar −1 ) and efficiency (99.7 ± 0.3%) for n -hexane/water mixtures, as well as excellent photodegradation efficiency (>99%) for methylene blue (MB). Remarkably, the optimized membrane exhibits remarkable scalability and stability, maintaining superior separation performance even after being rolled up 10 times with a curvature of 200 m −1 . This suggests that it has great potential for practical applications in complex environments.
研究领域:
材料科学
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环境工程
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膜技术
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电化学
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纳米材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2014
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IF 4.908
Choumou Zhou,Yalan Shi,Changsheng Sun,Sanchuan Yu,Meihong Liu,Congjie Gao
Novel flat-sheet thin-film composite membranes for nanofiltration were fabricated through interfacial polymerization of natural polymer sericin and trimesoyl chloride (TMC) on porous polysulfone support membrane. The preparation parameters including pH of aqueous phase , reaction time, curing temperature, curing time, sericin content and TMC concentration were investigated. The properties of the resultant membrane were characterized in terms of surface chemical structure , morphological structure, surface zeta potential , pure water flux, molecular weight cut-off (MWCO), pore size and rejections to different solutes including electrolytes and organic anionic dyes. It was found that the obtained sericin–TMC composite membranes had smooth and amphoteric surfaces with an isoelectric point at pH about 4.1. The membrane with a MWCO of 880 g/mol had a pure water permeability of 11.9 l/m 2 h bar and exhibited a salt rejection order of MgCl 2 (22.5%)
研究领域:
材料科学
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膜技术
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环境工程
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高分子化学
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水处理
✓ 已验证
DOI
高影响因子
ACS Omega
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2019
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IF 2.584
Dingsheng Wu,Quan Feng,Man Li,Anfang Wei,Jiali Li,Chen Liu,Hongguang Xu,Wangkai Cheng
To date, the preparation of a novel ultrafiltration membrane and the efficient separation and purification of protein solutions have gradually attracted widespread attention of many researchers. In this study, a hollow porous polystyrene/ethylene–vinyl acetate copolymer blend nanofibrous membrane (PS/EVA-BNM) was generated by electrospinning and chemical modification and then used to separate and purify proteins in solution. The BNM was characterized by scanning electron microscopy and specific surface area and pore size analyses. The membrane separation system was assembled using the BNM, which was overlaid to form the reaction layer. The optimal conditions for protein separation were determined by adjusting the operating pressure, filtration time, and pH. The results showed that the rejection rate of serum albumin and the membrane flux could reach 94.35% and 2.04 L/(m2 min), respectively, under the following conditions: the operating pressure was 0.10 MPa and the processing time was 1.5 h. By comparing the parameters of the polyethersulfone commercial ultrafiltration membrane with the PS/EVA-BNM system, it could be inferred that the rejection rate of the latter decreased slightly, whereas its transport flux improved several times. At the same time, the experimental results indicated that the PS/EVA-BNM possessed excellent reusability and mechanical properties. Additionally, the BNM could retain its nanofibrous morphological structure after the separation of serum albumin several times in an aqueous environment.
研究领域:
材料科学
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膜技术
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分离科学
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高分子工程
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生物技术
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
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IF 3.573
Xiangli Kong,Dawei Gong,Wei Ke,Minghui Qiu,Kaiyun Fu,Peng Xu,Xianfu Chen,Yiqun Fan
A ceramic membrane with multichannels generally has a higher specific area and larger throughput compared to that with a single channel, which is beneficial to the industrialization of ceramic membrane contactors for SO2 absorption. In this work, the mass transfer performance of SO2 absorption into NaOH solution was investigated at various gas and liquid operating conditions in a membrane contactor packed with a 19-channel hydrophilic membrane. The results showed that increasing the NaOH concentration can offset the effect of membrane thickness. To analyze the mass transfer process, a 3D mass transfer model was developed to simulate the concentration distribution of the components. The simulated SO2 fluxes were consistent with the experimental results. Additionally, the mass transfer model was applied to optimize the structure of channels in multichannel ceramic membranes. The operational mode of the multichannel ceramic membrane is optimized by blocking some inside channels to reduce the mass transfer resistance.
研究领域:
化学工程
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环境工程
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膜技术
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传质
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
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IF 3.131
Yi Yu,Mengfei Liu,Heng Zhang,Jinjie Qian,Yun Yang,Jinzheng Zhang,Nannan Liu,Shaoming Huang
A composite structure was constructed by in situ growth of ZIF-8 [Zn(MeIm) 2 , Melm = 2-methylimidazole] on the channels of anodized alumina oxide (AAO) membrane. The evolution of ZIF-8 MOF growing in situ crystallization in AAO nanochannels, can be divided into three stages through the observation at different time points. The reducing of the transmembrane ionic current can confirm the corresponding growth stage with the corresponding size of ZIF-8 nanocrystals . The method is applicable to modify ZIF-8 in AAO nanochannels of various diameters ranging from 71 ± 8 nm to 317 ± 36 nm, with the corresponding size of ZIF-8 ranging from 58 ± 8 nm to 272 ± 24 nm. The approach supplies a new composite nanopore material which can be utilized to the study of molecule–ZIF interaction.
研究领域:
材料科学
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纳米技术
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金属有机框架材料（MOFs）
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膜技术
✓ 已验证
DOI
高影响因子
ACS Applied Bio Materials
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2018
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IF 0
Zhong Yu,Zhongbo Zhou,Guocheng Huang,Xing Zheng,Linjie Wu,Shanshan Zhao,Fangang Meng
In-depth understandings of the interactions between NaOCl and foulants (e.g., alginate) at a molecular level can provide a deeper insight into the optimization of chemical cleaning. In this study, two-dimensional Fourier transform infrared correlation spectroscopic (2D-FTIR-COS) analysis was used to probe the hypochlorite oxidation of alginate at normal wastewater treatment operating pH (i.e., 6, 7, and 8). The 2D-FTIR-COS characterization indicated that the groups in alginate were degraded by NaOCl in a similar sequence at all investigated pHs: carboxylate groups (−COOH at pH 6 and 7) > C–O–C bonds, C–O bonds of uronic acids > C–O–C bonds. The results also showed that the presence of hemiacetals, which are formed by uronic acids, can protect alginate chains from oxidation during their initial exposure to NaOCl (30 min) and thus maintain alginate at a constant molecular size. Additionally, the rupture of C–O–C bonds resulting from initial oxidation (30 min) increased the viscosity of alginate solution because of the decreased stiffness of alginate chains and the rise of stronger intermolecular junctions. Long-term exposure to NaOCl (480 min) largely degraded uronic acids and the C–O–C bonds of alginate molecules, leading to decreases in molecular weight and viscosity at pH 6 and 7. However, because of the low degree of oxidation at pH 8, molecular weight and viscosity of alginates were slightly changed after long-term exposure (480 min) to NaOCl. Our results imply that the partial oxidation of alginate during hypochlorite scavenging enhanced its fouling propensity, which could have a potential implication for the implementation of chemical cleaning.
研究领域:
环境科学
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膜技术
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分析化学
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水处理
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光谱学
✓ 已验证
DOI
ACS Applied Materials & Interfaces
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2017
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IF 7.504
Hai Huang,Saisai Lin,Lin Zhang,Li’an Hou
Improving chlorine stability is a high priority for aromatic polyamide (PA) reverse osmosis (RO) membranes especially in long-term desalination. In this Research Article, PA RO membranes of sustainable chlorine resistance was synthesized. Glycylglycine (Gly) was grafted onto the membrane surface as a regenerative chlorine sacrificial layer, and the zeta-potential was used to monitor the membrane performance and to conduct timely regeneration operations for chlorinated Gly. The Gly-grafted PA membrane exhibited ameliorative chlorine resistance in which the N–H moiety of glycylglycine served as sacrificial pendants against chlorine attacks. Cyclic chlorination experiments, combined with FT-IR and XPS analysis, were carried out to characterize the membrane. Results indicated that the resulting N-halamines could be fast regenerated by a simple alkaline reduction step (pH 10). A synchronous relationship between the zeta-potential and the chlorination extent of the sacrificial layer was observed. This indicated that the zeta-potential can be used as an on-site sensor to conduct a timely regeneration operation. The intrinsic mechanism of the surface sacrificial process was also studied.
研究领域:
材料科学
·
环境工程
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膜技术
·
水处理
✓ 已验证
DOI
高影响因子
MACROMOLECULES
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2018
·
IF 5.914
Xiansong Shi,Zhi Xu,Chaobo Huang,Yong Wang,Zhanfeng Cui
This work is devoted to the development of high-flux ultrafiltration membranes using electrospun nanofibers of amphiphilic block copolymers (BCPs) of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) as building blocks. When soaked in hot ethanol, the solid as-spun BCP fibers are progressively transformed into three-dimensionally perforated fibers with increasing porosities with rising degrees of swelling, which ended up with the equilibrated morphology of spherical micelles. The BCP nanofibers are collected on macroporous substrates and subjected to heating to convert loosely stacked fibers to dense and continuous films. Subsequent swelling in hot ethanol leads to robust composite membranes with nanoporous BCP selective layers tightly adhered to the substrates. Filtration performances of the composite membranes can be conveniently modulated by electrospinning durations. The water permeabilities are as high as 6100 L m–2 h–1 bar–1, which is ∼10–35 times higher than that of commercial membranes with similar rejections. Moreover, with the surface enrichment of P2VP chains the membranes exhibit a strikingly sharp pH-dependent water permeability switchable in the largest amplitude ever reported for multiple cycles. Electrospun fibers can be promising building materials to produce a wide range of membranes with 3D interconnected nanoporosities which also show great potential in separation and biomedical applications.
研究领域:
材料科学
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膜技术
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高分子科学
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纳米技术
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分离科学
✓ 已验证
DOI
高影响因子
ACS Nano
·
2018
·
IF 13.709
Junchao Lao,Ruijing Lv,Jun Gao,Aoxuan Wang,Jinsong Wu,Jiayan Luo
High, stable, and modulatable ionic conductivity is important for many nanofluidic applications of layered two-dimensional (2D) membranes. In this study, we demonstrate a proton and ionic conductivity of the Ti3C2Tx membrane that is orders of magnitude higher than that of bulk solution at low concentrations. Importantly, the membrane is highly stable in aqueous solution without any modification, due to the strong and attractive interlayer van der Waals interaction and weak electrostatic repulsive interaction. Furthermore, by exploiting the intrinsic photothermal property of MXene, we demonstrate that the ionic conductivity can be reversely, rapidly, and completely switched on or off with laser light. This study should prove MXene membrane as a suitable platform to study and utilize nanofluidic ion transport. It should also inspire future studies to manipulate the mass transport through 2D membranes using their inherent physicochemical properties.
研究领域:
纳米流体力学
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材料科学
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膜技术
·
能量转换
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智能响应材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2011
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IF 3.673
Zhuan Yi,Li-Ping Zhu,Yi-Fan Zhao,Bao-Ku Zhu,You-Yi Xu
Polyethersulfone (PES) based amphiphilic block copolymer was designed as a hydrophilic additive for the modification of polysulfone (PSf) membranes. The block copolymer with PES as the middle block and poly(ethylene glycol) methyl ether methacrylate (POEM) as side blocks was synthesized via the reversible addition-fragmentation chain transfer (RAFT) polymerization, using a PES-based macro-chain-transfer-agent (macro-CTA). The successful synthesis of the amphiphilic copolymer was confirmed by the nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). Blend membranes were prepared via the non-solvent induced separation method. The differential scanning calorimetry (DSC) spectra of blend membranes displayed single glass transition temperatures ( T g ), indicating the miscibility between the PSf and PES main chains. The melting peak at 37.4 °C presented the phase separation of POEM from hydrophobic domains in membranes. The great improvements in hydrophilicity, fouling-resistance, and water flux were found when the modifier was introduced. At last, the intact of RAFT agents from the additives were made use of to graft zwitterionic brushes on membrane surface.
研究领域:
高分子科学
·
膜技术
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材料科学
·
表面改性
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）