The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Wu Tang - One of the best experts on this subject based on the ideXlab platform.
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Hydrophilic modification of poly(ether sulfone) used TiO2 nanoparticles by a sol–gel process
Journal of Materials Processing Technology, 2006Co-Authors: Wu Tang, Jian-qing Zhao, Chun-sheng PuAbstract:Abstract Poly(ether sulfone)/TiO2 (PES/TiO2) nanoparticle composites with different TiO2 content were prepared by a sol–gel process. These composites exhibited high optical transparency, having nanosized TiO2 rich domains well dispersed within PES matrix. The structure and properties of these composites were characterized by SEM, FT-IR, TGA, DMA and contact angle Test method, respectively. Hydrogen bonding interactions between the sulfone groups in the PES and the hydroxyl groups on the inorganic oxide were observed. Comparing with the pure PES polymer, the PES/TiO2 composites exhibited higher glass transition temperature, an increase and flattening of the rubbery plateau modulus and an increase in hydrophilicity. The mechanism of the hydrophilicity improvement of these composites was discussed.
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hydrophilic modification of poly ether sulfone ultrafiltration membrane surface by self assembly of tio2 nanoparticles
Applied Surface Science, 2005Co-Authors: Mingliang Luo, Jian-qing Zhao, Wu TangAbstract:Abstract Membrane fouling is one of the major obstacles for reaching the ultimate goal, which realizes high flux over a prolonged period of ultrafiltration (UF) operation. In this paper, TiO 2 nanoparticles of a quantum size (40 nm or less) in anatase crystal structure were prepared from the controlled hydrolysis of titanium tetraisopropoxide and characterized by X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM). The hydrophilic modification of poly(ether sulfone) UF membrane was performed by self-assembly of the hydroxyl group of TiO 2 nanoparticle surface and the sulfone group and ether bond in poly(ether sulfone) structure through coordination and hydrogen bond interaction, which was ascertained by X-ray photoelectron spectroscopy (XPS). The morphology and hydrophilicity were characterized by scanning electron microscopy (SEM) and contact angle Test, respectively. The composite UF membrane was also characterized in terms of separation behavior for polyethylene glycol-5000 solute. The experimental results show that the composite UF membrane has good separation performance and offers a strong potential for possible use as a new type of anti-fouling UF membrane.
Xi Chen - One of the best experts on this subject based on the ideXlab platform.
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The Research on Corona Aging Silicone Rubber Materials’ NMR Characteristics
IEEE Access, 2020Co-Authors: Yang Junwei, Xi Chen, Tianyan Jiang, Pan Aichuan, Dong YangAbstract:Nuclear Magnetic Resonance (NMR) detection is a non-destructive Testing method that can be used to detect the aging state of organic materials. A unilateral NMR sensor is used in this study to detect the aging state of the corona aging samples of silicone rubber materials after 100-hour’s corona aging under different humidity. At the same time, a comparative analysis is made between the NMR results and the conventional methods results such as Fourier Transform Infrared Spectroscopy (FTIR) and static contact angle Test. The results show that with the effect of corona discharge, the polymer structure of the silicone rubber materials change to a certain extent. These changes are shown as the effective transverse relaxation time $T_{\mathrm {2eff}}$ of aged sample decreases in the NMR detection. The results of NMR and FTIR both show that the molecular crosslinking density of silicon rubber materials increases, and the activity of the H-containing group decreases. With the increase of relative ambient humidity, $\Delta T_{\mathrm {2eff}}$ gradually increase, and it means the corona aging state is becoming much severer. The results of NMR are consistent with the results of FTIR and contact angle Tests. The $T_{\mathrm {2eff}}$ of the same sample Tested at different time does not have significantly changes. This indicates that the NMR characteristic of silicon rubber materials after corona are irreversible. The NMR method can Test the permanent damage of silicon rubber materials caused by corona. Compared with the static contact angle Test, the NMR method can analyze silicon rubber materials from the molecular structure level, and it has good portability and orientation. Meantime, NMR method can achieve a non-destructive aging state detection. Hence the NMR method will provide reference for the operation and maintenance of the silicone rubber composite insulator.
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Facile way in building superhydrophobic zirconium surface for controllable water-oil separation
Materials Letters, 2017Co-Authors: Yi Fan, Pingya Luo, Xi ChenAbstract:Abstract Superhydrophobic zirconium film with structure of mastoids like was prepared on the carbon fiber fabrics by a one-step electrochemical technique. Wettability, surface morphology and composition of the film were characterized with contact angle Test, SEM, FT-IR and XPS, respectively. According to the results of FT-IR and XPS, the chemical composition of the surface film was zirconium palmitate, and the wettability result was indicated with a water contact angle of 157°. Moreover, we fully discussed the fabricating process of this superhydrophobic surface. Besides, when the superhydrophobic fabric is placed in ammonia vapor, it turns hydrophilic and underwater superoleophobic. Therefore, a controllable process of water-oil separation was achieved.
Bahram Ramezanzadeh - One of the best experts on this subject based on the ideXlab platform.
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a detailed electrochemical theoretical exploration of the aqueous chinese gooseberry fruit shell extract as a green and cheap corrosion inhibitor for mild steel in acidic solution
Journal of Molecular Liquids, 2019Co-Authors: Ali Dehghani, Ghasem Bahlakeh, Bahram RamezanzadehAbstract:Abstract The aqueous extract of Chinese gooseberry fruit shell is a green source of various biologically active compounds like sucrose, maltose and folate, which are highly soluble in water and act as inhibiting molecules for carbon steel. The other components like methyl hexanoate, phytosterol and octadecadienoic acid are insoluble or less soluble in water and cannot be extracted from the Chinese gooseberry fruit shell through water-based extraction process. With corrosion inhibitory action in acidic environments. In the present work, the Chinese gooseberry fruit shell was used as a cheap waste material for extraction of green corrosion inhibitors for mild steel corrosion mitigation in subjection to HCl solution. Detailed explorations based on electronic-level density functional theory (DFT) and atomic-level molecular simulations (molecular dynamics and Mote Carlo) combined with electrochemical methods were applied to assess the Chinese gooseberry fruit shell corrosion inhibition characteristics, electronic properties, and interactions over the steel substrate in HCl solution. AFM, SEM, and contact angle Test were performed to assess the morphology of the unexposed and exposed metal surfaces. According to EIS results, 92% efficiency was derived using 1000 ppm extract after 2.5 h metal immersion in inhibited HCl solution. The polarization Test results clarified a prominent cathodic inhibition activity for this inhibitor with slight impact on the mechanism of hydrogen evolution reaction. The inhibition efficiency of Chinese gooseberry fruit shell extract was additionally evaluated by weight loss experiments at different temperatures and the results disclosed that during 5 h steel immersion at 25 °C the efficiency raised to 94% for 1000 ppm sample. Furthermore, the molecular simulation results clarified that the major active organic compounds of Chinese gooseberry fruit shell extract have a propensity to adsorb on the metal substrate enabling them to construct a corrosion preventing film over the surface, which is in support of experimental findings. The electronic-structure DFT studies evidenced the donor-acceptor interactions of reactive sites of inhibitor molecules. It is noteworthy that among different water-soluble ingredients of the Chinese gooseberry fruit shell extract the N-containing compounds including folate structure can supply more inhibiting activity than sucrose and maltose due to the presence of different polar oxygenated centers (i.e., hydroxyl and carbonyl) and importantly nitrogenous moieties (e.g., imine -N and amine -NH and -NH2). The stronger folate inhibition potentiality was computationally affirmed by DFT-evidenced strongest protonation affinity leading to its possible strongest physisorption and strongest MC/MD-proposed adsorption energies.
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Eriobotrya japonica Lindl leaves extract application for effective corrosion mitigation of mild steel in HCl solution: Experimental and computational studies
Construction and Building Materials, 2019Co-Authors: Saman Nikpour, Mohammad Ramezanzadeh, Ghasem Bahlakeh, Bahram Ramezanzadeh, Majid MahdavianAbstract:Abstract The feasibility of using Eriobotrya japonica Lindl (EJL) extract as a green inhibitor towards mild steel corrosion retardation in 1 M HCl solution was evaluated through integrated experimental and computational perspective. By utilizing electrochemical and surface analyses benefits, including EIS, potentiodynamic polarization, SEM, AFM and contact angle Test, the protection function of EJL extract was studied. In addition, the EJL extract itself was examined by means of FT-IR and UV–Vis analysis. EIS results revealed the increase in mild steel corrosion resistance in the presence of EJL extract by increasing the extract concentration. The highest resistance was achieved at 800 ppm concentration. A mixed type behavior of EJL extract with dominant anodic dissolution reduction was proved by DC polarization. The lowest current density was obtained at 800 ppm concentration. SEM and AFM images indicated the protective layer growth on steel surface having intact surface morphology and more homogeneity in the presence of inhibitor. Contact angle Test results confirmed the steel surface wettability enhancement by addition of EJL extract. The presence of functional groups, which make the inhibitors molecule adsorption possible, was verified by FT-IR and UV–Vis Tests results. Furthermore, the computational methods (i.e., quantum mechanics and molecular simulations) evidenced the binding of EJL extract compounds onto steel substrate, affirming the inhibition action of EJL extract.
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Utilizing Lemon Balm extract as an effective green corrosion inhibitor for mild steel in 1M HCl solution: A detailed experimental, molecular dynamics, Monte Carlo and quantum mechanics study
Journal of the Taiwan Institute of Chemical Engineers, 2019Co-Authors: Najmeh Asadi, Mohammad Ramezanzadeh, Ghasem Bahlakeh, Bahram RamezanzadehAbstract:Abstract This study concerns with mild steel corrosion inhibition in 1M HCl solution protected with different concentrations of Lemon Balm extract. Electrochemical and theoretical approaches are utilized for approaching this goal. The type of functional groups in the active components present in the Lemon Balm extract (LB.E) was examined through UV–visible analysis, Fourier Transform Infrared (spectroscopy) (FT-IR) and Raman spectroscopy. According to the electrochemical impedance spectroscopy (EIS) Test results the maximum inhibition efficiency of about 95% was obtained in the solution containing 800 ppm LB.E. Potentiodynamic polarization Test results revealed that in the presence of LB.E the rates of anodic steel dissolution and cathodic hydrogen evolution reactions significantly decreased and a mixed inhibition effect was obtained. Surface studies were done by contact angle Test, atomic force microscopy (AFM) and scanning electron microscopy (SEM). Results revealed that the steel surface damage as a result of HCl solution attack significantly decreased by addition of 800 ppm LB.E. In addition, deposition of a highly hydrophobic film composed of organic compounds of inhibitors on mild steel surface was demonstrated by contact angle Test results. The excellent corrosion inhibition effect of LB.E on mild steel in HCl solution is related to the adsorption of active inhibitive compounds such as caryophyllene, germacrene, citral, luteolin, chlorogenic acid and rosmarinic acid on the anodic/cathodic places of mild steel surface. Furthermore, the theoretical results derived from Monte Carlo, molecular dynamics and quantum mechanics techniques evidenced the inhibitors adsorption onto steel substrate through donor-acceptor interactions.
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glycyrrhiza glabra leaves extract as a green corrosion inhibitor for mild steel in 1 m hydrochloric acid solution experimental molecular dynamics monte carlo and quantum mechanics study
Journal of Molecular Liquids, 2018Co-Authors: Eiman Alibakhshi, Mohammad Ramezanzadeh, Majid Mahdavian, Ghasem Bahlakeh, Bahram Ramezanzadeh, Milad MotamediAbstract:Abstract The objective of this study is to investigate the inhibition of Glycyrrhiza glabra extract, commonly known as licorice, as a green source of corrosion inhibitor against mild steel corrosion in 1 M HCl solution. The extract of Glycyrrhiza glabra has been used for mild steel inhibition in 1 M HCl solution. By means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) the corrosion inhibition performance and by atomic force microscopy (AFM) and contact angle Test the surface characteristics were evaluated. The results of polarization Test revealed that the Glycyrrhiza glabra leaves extract acted as mixed type inhibitor and retarded both anodic and cathodic reactions rates. Results revealed that by addition of Glycyrrhiza glabra leaves extract the corrosion current density of mild steel significantly decreased from 260 μA/cm2 for the sample without inhibitor to 40.2 μA/cm2 for the sample containing 800 ppm inhibitor. In addition, it was found that in the presence of Glycyrrhiza glabra leaves extract the hydrogen evolution mechanism did not change but the anodic dissolution mechanism of iron was affected in the presence of inhibitors. The EIS results showed that the increase of Glycyrrhiza glabra leaves extract concentration and immersion time resulted in the increase of corrosion inhibition efficiency. The maximum corrosion inhibition efficiency (about 88%) and surface coverage (about 72%) were obtained in the presence of 800 ppm Glycyrrhiza glabra leaves extract after 24 h immersion. Atomic force microscopy Test results showed lower mild steel surface degradation in the HCl solution with 800 ppm Glycyrrhiza glabra leaves extract. Also, the decrease in surface hydrophilicity in the presence of Glycyrrhiza glabra leaves extract confirmed the adsorption of organic molecules of the inhibitors, such as Glycyrrhizin (GL), 18β-Glycyrrhetinic acid (GA), Liquritigenin (LTG), Licochalcone A (LCA), Licochalcone E (LCE), and Glabridin (GLD), on the active sites of mild steel. In addition, the modeling studies based on classical molecular dynamics (MD), Monte Carlo (MC) and quantum mechanics (QM) techniques evidenced that all corrosion inhibiting materials exist in Glycyrrhiza glabra adsorbed to steel surface, and thereby form a corrosion-protective film over the steel surface.
Z Y Huang - One of the best experts on this subject based on the ideXlab platform.
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Structure and haemocompatibility of ZnO films deposited by radio frequency sputtering.
Biomedical materials (Bristol England), 2009Co-Authors: Z Y Huang, Chen Min, Shi-rong Pan, Dihu ChenAbstract:ZnO films were first deposited on silicon and glass substrates using radio frequency sputtering and then annealed in air at different temperatures from 300 to 700 degrees C. The microstructures, surface energy and optical properties of ZnO films were examined by x-ray diffraction, Raman spectroscopy, contact angle Test and UV-visible optical absorption spectroscopy, respectively. Results show that a perfectly oriented ZnO (0 0 2) thin film is obtained in all ZnO samples. Raman spectroscopy, in combination with those derived by UV-visible optical absorption spectroscopy, provides us with an accurate description of ZnO nature, revealing that, after annealing, ZnO films exhibit better crystallinity and narrower optical energy gap. The contact angle Test denotes that the adhesive work and polar component of the surface energy of ZnO films increase steadily with the annealing temperature, which leads to more active interaction between annealed ZnO films and blood plasma. The platelet adhesion experiment shows that there are fewer platelets adhered to the surface of ZnO films compared to the polyurethane (PU) used in clinical application, suggesting ZnO's better compatibility with blood. As the annealing temperature increases, the number of platelets adhered to ZnO films increases correspondingly, which we believe is due to the narrower optical energy gap. Therefore, the appropriate surface properties and the wide optical energy gap of ZnO thin films are believed to be the main factors responsible for the excellent haemocompatibility.
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Blood compatibility improvement of titanium oxide film modified by doping La2O3
Journal of Materials Science: Materials in Medicine, 2009Co-Authors: L. Zhang, Fengmei Yu, D H Chen, Keqiang Wang, Z Y HuangAbstract:La2O3 doped titanium oxide (TiO2) films with different concentration were deposited by means of the Radio-Frequency magnetron sputtering technique. The microstructure and surface properties of TiO2 films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and contact angle Test. The blood compatibility of the specimens was evaluated by Tests of platelet adhesion. Results show that pure rutile phase is formed in doped samples and La2O3 incorporation significantly improves the wettability and hemocompatibility of TiO2 films. Our studies demonstrate that La2O3 doped TiO2 films are potentially useful biomaterials with good blood compatibility.
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Blood compatibility of La2O3 doped diamond-like carbon films
Diamond and Related Materials, 2008Co-Authors: L. Zhang, P. Lv, Z Y Huang, D H Chen, Min ChenAbstract:Abstract La2O3 doped diamond-like carbon films (DLC) with different concentration were deposited by using Radio-Frequency magnetron sputtering. The microstructure and surface properties of DLC films were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and contact angle Test. The blood compatibility of the samples was evaluated by Tests of platelet adhesion. Results show the sp2-bonded C content increases with increasing of La2O3 concentration doped. A remarkable decrease of platelet adhered on the surface of the La2O3 doped DLC films was observed comparing to the Chrono flex used in clinical application, suggesting that La2O3 doped DLC is able to enhance its blood compatibility. The mechanism of hemocompatibility of doped films was discussed. Our results demonstrate that La2O3 doped DLC films are potentially useful biomaterials with good blood compatibility.
Jian-qing Zhao - One of the best experts on this subject based on the ideXlab platform.
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Hydrophilic modification of poly(ether sulfone) used TiO2 nanoparticles by a sol–gel process
Journal of Materials Processing Technology, 2006Co-Authors: Wu Tang, Jian-qing Zhao, Chun-sheng PuAbstract:Abstract Poly(ether sulfone)/TiO2 (PES/TiO2) nanoparticle composites with different TiO2 content were prepared by a sol–gel process. These composites exhibited high optical transparency, having nanosized TiO2 rich domains well dispersed within PES matrix. The structure and properties of these composites were characterized by SEM, FT-IR, TGA, DMA and contact angle Test method, respectively. Hydrogen bonding interactions between the sulfone groups in the PES and the hydroxyl groups on the inorganic oxide were observed. Comparing with the pure PES polymer, the PES/TiO2 composites exhibited higher glass transition temperature, an increase and flattening of the rubbery plateau modulus and an increase in hydrophilicity. The mechanism of the hydrophilicity improvement of these composites was discussed.
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hydrophilic modification of poly ether sulfone ultrafiltration membrane surface by self assembly of tio2 nanoparticles
Applied Surface Science, 2005Co-Authors: Mingliang Luo, Jian-qing Zhao, Wu TangAbstract:Abstract Membrane fouling is one of the major obstacles for reaching the ultimate goal, which realizes high flux over a prolonged period of ultrafiltration (UF) operation. In this paper, TiO 2 nanoparticles of a quantum size (40 nm or less) in anatase crystal structure were prepared from the controlled hydrolysis of titanium tetraisopropoxide and characterized by X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM). The hydrophilic modification of poly(ether sulfone) UF membrane was performed by self-assembly of the hydroxyl group of TiO 2 nanoparticle surface and the sulfone group and ether bond in poly(ether sulfone) structure through coordination and hydrogen bond interaction, which was ascertained by X-ray photoelectron spectroscopy (XPS). The morphology and hydrophilicity were characterized by scanning electron microscopy (SEM) and contact angle Test, respectively. The composite UF membrane was also characterized in terms of separation behavior for polyethylene glycol-5000 solute. The experimental results show that the composite UF membrane has good separation performance and offers a strong potential for possible use as a new type of anti-fouling UF membrane.