MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 6
·2031-2037
·
IF 4.831
Xu Guiyun,Liang Shaoping,Fan Jinshi,Sheng Ge,Luo Xiliang
Negatively charged carboxylated nanocrystalline cellulose (CNCC) and positively charged poly(diallyldimethyl ammonium chloride) (PDDA) were alternatingly assembled on the surface of a glassy carbon electrode to form a relatively uniform polyelectrolyte multilayer nanocomposite (CNCC/PDDA) n . It was then incorporated into a matrix of conducting poly(3,4-ethylenedioxythiophene) (PEDOT) electrodeposited on the surface of the electrode. The nanocomposites were prepared in various ratios of PEDOT and (CNCC/PDDA), and then characterized by transmission electron microscopy, scanning electron microscopy, electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry. The PEDOT/(CNCC/PDDA) 4 nanocomposite showed the lowest electrochemical impedance and best electrocatalytic activity towards the oxidation of nitrite. Based on these findings, an amperometric sensor was developed which, if operated at 0.80 V (vs. SCE), can detect nitrite in the 0.2 μM to 1.73 mM concentration range with a 57 nM detection limit.
Carboxylated nanocrystalline cellulose (CNCC) and poly(diallyldimethyl ammonium chloride) (PDDA) were assembled to nanocomposite (CNCC/PDDA) n . Poly(3,4-ethylenedioxythiophene (PEDOT) was electrodeposited on the surface of (CNCC/PDDA) n and a sensitive amperometric sensor for detection of nitrite was developed based on PEDOT/(CNCC/PDDA) n .
研究领域:
分析化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yanling Chai,Jinchao Chen,Xiaofeng Fang,Fang Li,Xingran Zhang
Polyelectrolyte multilayer nanofiltration (NF) membranes have garnered attention for their potential in Mg 2 ⁺/Li⁺ separation applications, particularly due to their positively charged nature and the versatility offered by the layer-by-layer (LbL) self-assembly technique. However, these membranes often face significant challenges in balancing high ion selectivity with adequate water permeability. Addressing these limitations, this study introduces a novel approach by grafting a zwitterionic material, trimethylamine N-oxide (TMAO), onto polyacrylamide hydrochloride (PAH), creating a new cationic polyelectrolyte (TPAH). By cyclically depositing sodium polystyrene sulfonate (PSS) and TPAH onto a polyethersulfone (PES) substrate, we have successfully fabricated a high-performance NF membrane ( i.e. , (PSS/TPAH) n ) that demonstrates enhanced Mg 2 ⁺/Li⁺ selectivity with high water permeability. TMAO features shorter distances between its positive and negative charge groups and smaller dipoles compared to other zwitterions. These characteristics enhance its ability to resistance to salt effects and transfer charge from amine oxide to water molecule. Furthermore, the grafting of TMAO enhanced the hydrophilicity of TPAH and regulated the charge distribution of the polyelectrolyte. Compared to the control membrane (PSS/PAH) n , the optimized membrane (PSS/TPAH) n showed reduced rejection of LiCl from 60.9 ± 2.7 % to 35.9 ± 1.5 %, while that of MgCl 2 increased from 94.3 ± 1.6 % to 96.1 ± 0.7 %. Additionally, water permeability improved from 9.2 ± 0.9 LMH/bar to 16.1 ± 0.5 LMH/bar. Notably, the membranes exhibited an improved selectivity for Mg 2+ /Li + ions in synthetic saline, reaching a maximum of 30.5 ± 1.5, highlighting its potential for practical separation applications. Density functional theory simulations indicate that TMAO not only enhances Donnan effect and intensify ion dehydration of polyelectrolyte multilayers NF membranes but also increases their hydrophilicity. In general, these polyelectrolyte multilayers NF membranes exhibit considerable promise for multiple applications, such as seawater pretreatment, groundwater softening and lithium extraction.
研究领域:
材料科学
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环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Xiaopeng Zhang,Yulong Li,Rui Zhang,Ying Chen,Gaofeng Zhao,Weizhen Zhao,Xia-Chao Chen,Suojiang Zhang
Polyelectrolyte multilayers have received broad interests in the fields of functional coatings due to their easy deposition procedure, environmentally friendly nature and wide sensitivities to manifold external stimuli. Stimuli-triggered generation of nanoscopic structures on polyelectrolyte multilayers can be reversible generally when their structural size is less than dozens of nanometers. Transforming larger structures reversibly would represent a breakthrough of these materials for novel applications. Herein, we report that surface structures up to hundreds of nanometers can be developed on exponentially growing polyelectrolyte multilayers reversibly, which feature the diffusion of polyelectrolytes throughout the whole assemblies. These multilayers are prepared utilizing pH-amplified layer-by-layer assembly of branched polyethylenimine and photo-reactive poly(acrylic acid) azido derivative. Other than applying a single stimulus on the mobility of polymeric chains, the surface structures were developed by inducing electrostatic repulsion between chains in aqueous phases while subsequently erased by shielding supramolecular electrostatic interactions in gaseous phases. These processes are completely reversible and one potential application of this dynamic platform is to be a “smart” material for reversible visualization of various high-definition patterns with fine brightness contrast, which can be especially significant in some cutting-edge fields like the Internet of Things, information encryption/decryption and anti-counterfeiting. Beyond that, such dynamic platform can be very useful in many other research fields, such as surface wettability and smart homes.
研究领域:
材料科学
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纳米技术
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表面化学
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Jialin Wei,Zhiyuan Qiao,Dinghe Yan,Jingwen Chu,Xinyi Zheng,Dawei Ji,Changfa Xiao,Chun Wang
In this study, we deposited polyelectrolyte multilayers (PEMs) on Poly ( p -phenylene terephthamide) (PPTA) ultrafiltration (UF) substrates with strong polyelectrolytes (PEs): polystyrene sulfonic acid (PSS) and poly (diallyldimethylammonium chloride) (PDADMAC). The growth pattern of PEMs was shifted from linear to exponential by changing substrate potential, which was attributed to synergism and antagonism of dispersion of PEs on hydrophilic substrates and electrostatic interaction between PEs and substrates. Eventually, PEMs of layer-dominated and pore-dominated regimes were successfully obtained. We focused on the transition from the pore-dominated to the layer-dominated regime of PEMs. The PEMs nanofiltration (NF) membranes in this situation showed a better separation performance due to the together work of the interface and in-pore energy barriers. The retention rate of Na 2 SO 4 and MgSO 4 was 98 % and 91 %. The eosin Y retention rate was 99.9 % and only declined 2 % after 100 h. The hindered deposition of pore-dominated regimes led to denser and thinner layers, which achieved long-term acid resistance. It maintained a stable salt retention after 185 h cross-filtration of 0.1 M H 2 SO 4 feed solution. The performance of PEMs NF membrane was improved from a new perspective, and excellent acid-resistant nanofiltration membranes were obtained, which are expected to be used to treat industrial acidic wastewater.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2012
·
IF 3.696
Bo Wu,Chunliang Li,Haiyang Yang,Guangming Liu,Guangzhao Zhang
Poly(sodium 4-styrene sulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDDA) are flexible polyelectrolytes, whereas sulfated chitosan (SC) and cationic guar gum (CGG) are semiflexible polyelectrolytes. By use of a quartz crystal microbalance with dissipation (QCM-D), a zeta potential analyzer (ZPA), and atomic force microscopy (AFM), we have investigated the growth of PSS/PDDA, PSS/CGG, SC/PDDA, and SC/CGG multilayers as a function of NaCl concentration (CNaCl). For the same layer number, the changes of frequency (−Δf) and dissipation (ΔD) regarding PSS/PDDA multilayer increase with CNaCl, whereas −Δf and ΔD for SC/CGG multilayer increase at CNaCl < 0.1 M and decrease at CNaCl > 0.1 M as CNaCl increases. In the cases of PSS/CGG and SC/PDDA multilayer, for the same layer number, −Δf and ΔD increase with CNaCl in the range of CNaCl < 0.5 M, and they decrease with the increasing CNaCl in the case of SC/PDDA multilayer but slightly change for the PSS/CGG multilayer at CNaCl > 0.5 M. QCM-D studies indicate that the growth of multilayers as a function of salt concentration is determined by the delicate balance between the weakening of electrostatic repulsion between identically charged groups and the decrease of electrostatic attraction between neighboring layers. ZPA and AFM measurements demonstrate that the extent of surface charge overcompensation and the surface morphology of the multilayers are controlled by the chain conformation.
研究领域:
材料科学
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表面化学
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生物物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 132
·期 8
·
IF 1.64
Huining Deng,Zixia Wang,Wei Zhang,Baisong Hu,Shaofeng Zhang
This study reports the modification of commercial cation-exchange membrane by layer-by-layer adsorption of polyethyleneimine and poly(acrylic acid) (PAA) to endow them with monovalent ion selectivity. The chemical and morphological changes of the modified membrane surface were examined by ATR-FTIR and SEM, respectively. The permselectivity for monovalent cations of the membranes was investigated by electrodialysis experiments. The effects of deposited bilayer number, the salt concentration, and pH of the dipping polyelectrolyte solutions on selectivity were investigated. Meanwhile, the resistance of membranes was measured taking energy consumption into consideration. The polyelectrolyte multilayer was crosslinked using epichlorohydrin to improve stability, and the durability of the composite membrane was studied. Separation mechanism of the composite membrane was also investigated. It is demonstrated that the bivalent cations are mainly rejected by electrostatic repulsion from the positive charge on the surface of the composite membranes. The sieving effect of the dense structure of skin layer becomes more pronounced with the number of deposited layers increased. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41488.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Soft Matter
·
2018
·Vol. 14
·期 6
·961-968
·
IF 3.709
Bo Wu,Guangming Liu,Guangzhao Zhang,Vincent S. J. Craig
Colloidal interactions have been characterised using both osmotic stress and surface forces. Here these methods are employed concurrently to measure the interaction forces of polyelectrolyte multilayers that when cross-linked form a dextran impermeable membrane. The force data, corrected for the thickness of the polyelectrolyte multilayer film, has been expressed as pressure versus separation enabling the interaction from osmotic stress measurements to be compared to the measured interaction from the colloid probe technique. The combined technique is valuable in evaluating the interaction forces associated with compression of polymer films at different rates and over a wide range of pressure and demonstrates features that are not revealed when just one technique is employed. The combination of the techniques allows both attractive forces and strongly repulsive forces to be measured and shows that the measured repulsion is greater in the force data than in the osmotic data. This is due to insufficient equilibration time in the AFM measurements, even at the slowest approach rates available, indicating that AFM force measurements between polyelectrolytes will always contain a dynamic component. That is we demonstrate that colloid probe measurements between polymer surfaces overestimate the equilibrium repulsive interaction due to the rate at which the measurement is performed.
研究领域:
材料科学
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表面化学
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生物物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CONTROLLED RELEASE
·
2019
·
IF 7.901
Xinfang Li,Qinan Xu,Peng Zhang,Xiao Zhao,Youxiang Wang
Transdermal gene therapy is a useful treatment for many skin lesions. By penetrating stratum corneum directly, microneedle patch (MNP) has been widely investigated to improve transdermal gene delivery. However, considering the operability and patience compliance, quick gene release was required after insertion. In this research, by utilizing acidic cutaneous environment, pH-responsive polyelectrolyte multilayers (PEM) were coated on the surface of polycaprolactone (PCL) microneedles by layer-by-layer assembly to realize rapid gene release. Dimethylmaleic anhydride-modified polylysine (PLL-DMA), a charge reversible polymer, was introduced to PEM. The PEM composed of two parts: the transition layers of (PLL-DMA/polyethyleneimine) 12 and the gene-loaded layers of (p53 expression plasmid/polyethyleneimine) 16 . Microneedle patch modified with such PEM was marked as tr-MNP. In following experiment, Hoechst 33258 dyed model DNA was used to track modification process, fluorescent intensity of tr-MNP was obviously strengthened while the number of bilayers increased and the morphology could be maintained. Each tr-MNP could load 31 μg model DNA and improve gene release. To prove this character, MNP without transition layers (ntr-MNP) was fabricated as control. Tr-MNP could release 33% of model DNA in simulative cutaneous environment (phosphate buffer saline; pH = 5.5) while ntr-MNP could only release 4%. That was because PLL-DMA could achieve charge reversal in acidic cutaneous environment, leading to the collapse of transition layers and promoted the gene release. In vivo experiment showed tumor inhibit efficacy of tr-MNP treated mice could reach 90.1% while that of ntr-MNP treated mice and intravenous administration mice was only 46.4% and 30.5%. Overall, the pH-responsive gene loaded MNP could treat subcutaneous tumor efficiently and showed potential to be a platform to load many biomacromolecule.
研究领域:
药学
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生物医学工程
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癌症研究
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 54
·33764-33774
·
IF 3.108
Xia Zhao,Zuquan Jin,Binbin Zhang,Xiaofan Zhai,Shuan Liu,Xiaolin Sun,Qingjun Zhu,Baorong Hou
Corrosion of aluminum alloys (Al alloys) has been a ubiquitous problem, and this seriously restricts its range of applications. Herein, a layer-by-layer (LBL) self-assembly method based on the formation and deposition of polyelectrolyte multilayers was employed to fabricate anticorrosion layers on 2A12 Al alloys for corrosion protection. LBL self-assembled films, with and without graphene oxide, were formed on Al alloy surface. The surface morphologies, roughness and chemical compositions of the as-fabricated LBL self-assembled films were characterized by several methods, such as, SEM, AFM, and XPS techniques. The electrochemical properties of the specimens were determined by EIS measurements. The comprehensive equivalent circuits were established to analyze the anticorrosion performance and inhibition efficiency of the resultant LBL self-assembled surfaces. The results indicate that the LBL self-assembled film exhibits inhibition efficiency over 99% in a 3.5% NaCl solution. After dragging to a distance of 200 mm or 400 mm, the inhibition efficiency of the LBL self-assembled film containing graphene oxide can still exceed 96%. LBL self-assembled films are considered to provide a new strategy for marine corrosion protection.
研究领域:
材料科学
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腐蚀与防护
·
电化学
✓ 已验证
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2015
·
IF 1.998
Xiaodan Zhang,Jinhong Yi,Guowei Zhao,Linlin Huang,Guangjun Yan,Yashao Chen,Peng Liu
Functionalization of magnesium alloy (Mg alloy) with multiple bioactivities is desired to obtain surfaces with improved biocompatibility and antibacterial property. In this article, an anticorrosive and antimicrobial coating was prepared on Mg alloy surface by layer-by-layer (LbL) assembly of polyelectrolytes . A polycationic copolymer (P(DOP- co -DMAEMA + )) bearing dopamine (DOP) and 2-(methacryloxy)ethyl trimethylammonium chloride (DMAEMA + ) was synthesized and deposited on the surface of micro-arc oxidation (MAO) treated Mg alloy substrate as the first layer. The presence of DOP units ensure a strong anchoring on Mg alloy substrate, and the –N + (CH 3 ) 3 groups are sources of positive charge, providing electrostatic interaction with polyanion electrolyte. Negatively charged colloidal silver particles were prepared by using dextran sulfate (DS) as a stabilizer to precede chemical reduction by dextrose and served as a polyanion electrolyte. The functional polyelectrolyte multilayered films were obtained by alternating deposition P(DOP- co -DMAEMA + ) and DS-stabilized silver colloid (DS-Ag) in a spin-assisted LbL assembly manner. The prepared nanosized silver colloids and functionalized Mg alloy were characterized by ultraviolet–visible (UV–vis) spectroscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Potentiodynamic polarization test confirmed that corrosion resistance of modified Mg alloy significantly increased and the fabricated polyelectrolyte multilayer films showed significant antibacterial activity .
研究领域:
材料科学
·
生物材料
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表面工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Lihong Gan,Jin Zhang,Yangtao Wu,Zhuo Chen,Zhenyu Zhao,Shihong Lin,Yi Jiang
Polyelectrolyte multilayer (PEM) membranes, with advantageous features of versatile chemistry and structures, are driving the development of advanced nanofiltration (NF) membranes with exceptional performance. While developing a printing method holds great promise for the eventual mass production of these membranes, reports on the printing method and the underlying mechanisms of membrane formation are currently scarce. Herein, we develop an aerosol-assisted printing (AAP) system for fabricating PEM NF membranes with highly tunable separation characteristics. Our study unveils the three stages of membrane formation from assembly of polyethylenimine (PEI) and poly(sodium 4-styrenesulfonate) (PSS): aerosol deposition, single PE layer formation, and PEM assembly. The droplet deposition is governed by inertial impaction, and the deposited PEs migrate/entangle to form a single PE layer. The thicknesses of the PE layer and PEM exhibit linear growth as the number of printing scan increases. Furthermore, PE interdigitation forms an effective polymeric network barrier, which increases the resistance to solute and water transport. By manipulating the PE deposition mass and layering, PEM membranes with tunable pore radii (0.40–0.56 nm) and water permeability (5–60 L·m–2·h–1·bar–1) were obtained for various water treatment applications, ranging from micropollutant removal to humic acid filtration. Our study offers valuable mechanistic insights into the PEM formation and precise structural adjustment via printing, thus facilitating scalable manufacturing and widespread applications of the PEM NF membranes.
研究领域:
材料科学
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环境工程
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Weihua Xu,Yanling Liu,Kaiming Fan,Ziyi Yuan,Siqi Wang,Linjun Li,Shengji Xia
The widespread presence of hardness ions in surface water poses potential challenges for drinking water treatment, which can be efficiently removed by nanofiltration (NF) membranes. Compared with mainstream spiral-wound polyamide ones, hollow fiber (HF) NF membranes present a promising alternative due to the potential advantages in operation. This study investigated the ion rejection properties of a commercial polyelectrolyte multilayer (PEM)-based HF NF membrane by treating surface water with varying hardness levels, respectively resembling the raw water hardness of northern and southern areas of China. Results show that compared to NF270 membrane, the PEM HF NF membrane had a thicker separation layer with higher surface hydrophobicity, leading to a lower water permeance. Despite the predominantly negatively charged surface, the PEM HF NF membrane achieved high CaCl 2 and MgCl 2 rejections of 85.4 % and 90.2 %, respectively. During surface water treatment, the PEM HF NF membrane maintained stable water purification performance after several cycles of backwashing and outperformed NF270 membrane in removing organic matters and hardness ions. The distinct ion rejection characteristics and underlying mechanisms for the PEM HF NF membrane treating surface water with different hardness levels were comprehensively elucidated. Moreover, the membrane negative rejection of Na + in low hardness water affected by the Na + /Cl - molar ratio in the feed was particularly interpreted. This study provides performance demonstration and mechanistic insights for promoting the potential application of PEM HF NF membranes for drinking water treatment.
研究领域:
环境科学
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材料科学
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水处理工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）