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Effect of Heating Rates on the Formable Oxide Scale on a C-Steel Surface

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Journal of Materials Science & Technology 2004年第5期20卷 591-594页

作者： A.A.El-Meligi electrochemistry and Corrosion lab. Dept.of Physical ChemistryNational Research CentreDokkiCairoEgypt

Oxide scale formation on a C-steel surface has been investigated using linear heating rates ranging from 0.1℃/min to 10℃/min at high temperatures. The studies on the oxide scale formation at high temperature (650℃) at slower heating rate (0.1℃/min) shows that the kinetic regime is linear. X-ray diffraction measurements revealed that the scale constituents are significantly influenced by the heating rate. The adherence of the scale was improved by using slower heating rate (0.1℃/min-≤650℃), while above such degree the scale was susceptible to cracking and flaking out of the alloy surface. In fact, the development of oxide growth stresses can cause considerable scale cracking. As well, variation of the crystallite sizes under the aforementioned conditions might affect the scale stacking to the alloy surface. The secondary electron detector images of the oxide scale shows that the scale was imperfectly smooth and there were a number of voids and defects in the scale skin, especially at fast heating rate. This observation could be attributed to defects of the as-received alloy. In general, slower heating rate reduced the defects of the scale and improved its adherence.

关键词： C-steel Oxide scale Heating rate Weight gain XRD

Role of Chloride Ion and Dissolved Oxygen in Electrochemical Corrosion of AA5083-H321 Aluminum-Magnesium Alloy in NaCl Solutions under Flow Conditions

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Journal of Materials Science & Technology 2007年第5期23卷 623-628页

作者： K.Jafarzadeh T.Shahrabi S.M.M.Hadavi M.G.Hosseini Department of Materials Engineering.Tarbiat Modares University TehranIran Faculty of Material Engineering Malek Ashtar UniversityTehranIran electrochemistry research lab. Chemistry FacultyTabriz UniversityTabrizDan

Flow-induced corrosion consists electrochemical and mechanical components. The present paper has to assessed the role of chloride ion and dissolved oxygen in the electrochemical component of flow induced corrosion for AA5083-H321 aluminum-magnesium alloy which is extensively used in the construction of high-speed boats, submarines, hovercrafts, and desalination systems, in NaCI solutions. Electrochemical tests were carried out at flow velocities of 0, ：2, 5, 7 and 10 m/s, in aerated and deaerated NaCI solutions with different sodium chloride concentrations. The results showed that the high rate of oxygen reduction under hydrodynamic conditions causes an increase in the density of pits on the surface. The increase of chloride ions concentration under flow conditions accelerates the rate of anodic reactions, but have no influence on the cathodic reactions. Thus, in the current work, it was found that under flow conditions, due to the elimination of corrosion products inside the pits, corrosion resistance of the alloy is increased.

关键词： Corrosion Flow NaCl solution AA5083-H321 aluminum-magnesium alloy Chloride ion Oxygen

Chemical incorporation of SiO_(2) into TiO_(2) layer by green plasma enhancer and quencher agents for synchronized improvements in the protective and bioactive properties

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Nano Materials Science 2024年第5期6卷 596-610页

作者： Mosab Kaseem Ananda Repycha Safira Mohammad Aadil Han-Choel Choe Corrosion and electrochemistry laboratory Department of Nanotechnology and Advanced Materials EngineeringSejong UniversitySeoul05006South Korea Advanced Functional Surface and Biomaterials research lab Department of Dental Materials and Research Center of Surface Control for Oral Tissue Regeneration(BRL Center of NRF)Convergence Research Center for Treatment of Oral Soft Tissue Disease(MRC)College of DentistryChosun UniversityGwangju61452South Korea

This study explores the dynamic interaction between environmentally sustainable plasma enhancer and quencher agents during the incorporation of SiO_(2) into a TiO_(2) layer,with the primary objective of simultaneously augmenting protective and bioactive *** enhancement is realized through the synergistic utilization of Tetraethyl orthosilicate(TE)and Stevia(ST)within a plasma-assisted oxidation *** achieve this goal,Ti–6Al–4V alloy underwent oxidation in an electrolyte solution containing acetate-glycerophosphate,with the addition of TE and ST separately and in ***,as a silicon oxide(SiO_(2))precursor,facilitates the creation of a calcium-rich,rough,porous layer by undergoing hydrolysis to generate silanol groups(Si–OH),which subsequently condense into silicon-oxygen-silicon(Si–O–Si)bonds,resulting in SiO_(2) *** contrast,ST acts as a plasma quencher,absorbing highly reactive plasma species during the oxidation process,reducing energy levels,and diminishing sparking *** combination of TE and ST results in moderate sparking,balancing Stevia's quenching effect and TE's sparking *** a result,this coating exhibits enhanced corrosion resistance and bioactivity compared to using either ST or TE *** study highlights the potential of this synergistic approach for advanced TiO_(2)-based coatings.

关键词： Ti-6Al-4V alloy Plasma quencher Hydrolysis Corrosion Bioactivity

Imidazolium-Based Ionic Liquids as an Anticorrosive Agent for Completion Fluid Design

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Journal of Earth Science 2017年第5期28卷 949-961页

作者： Sugirtha Velusamy Sivabalan Sakthivel Lakshman Neelakantan Jitendra S.Sangwai Petroleum Engineering Program Department of Ocean EngineeringIndian Institute of Technology Madras Department of Chemistry Madras Christian College electrochemistry and Corrosion lab Department of Metallurgical and Materials EngineeringIndian Institute of Technology Madras

Most of the onshore and offshore oil and gas reservoirs are facing operational challenges due to high temperature and high salinity, thus requiring advanced techniques for realizing the ex- pected oil recovery with the use of specially designed chemicals. During oil and gas well development, completion fluids, which are solids-free liquids, are used to complete an oil or gas well. Completion flu- ids consisting of brines are primarily used for oil and gas well stabilization and are corrosive in nature. There is a need to develop additives to be added with completion fluids to address the corrosive nature. The present investigation involved the usage of two imidazolium ionic liquids （ILs） as corrosion inhibi- tors for mild steel in various completion brine （CaCI2, HCOOCs and ZnBr2） fluids. The study was per- formed using various techniques, such as, potentiodynamic polarization, weight loss measurements and exposure studies. All the above techniques showed promising results which indicated that the ILs as corrosion inhibitors used were of the mixed-type following both physisorption and chemisorption over the mild steel surface. Among the two inhibitors studied here, l-octyl-3-methyl imidazolium chlo- ride （[OMIM]^＋[CI]^-） with longer alkyl chain exhibited better inhibition efficiency and much lesser cor- rosion rate than 1-butyl-3-methyl imidazolium chloride （[BMIM]^＋[Ci]^-） with a shorter alkyl chain. The results obtained from various methodologies indicate that ionic liquids can be explored to develop anti-corrosive completion fluids suitable for oil and gas reservoirs.

关键词： completion fluid corrosion electrochemical ionic liquid inhibition mild steel.

Phase Transformation of Lithium-rich Oxide Cathode in Full Cell and its Suppression by Solid Electrolyte Interphase on Graphite Anode

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Energy & Environmental Materials 2020年第1期3卷 19-28页

作者： Wenqiang Tu Yucheng Wen Changchun Ye Lidan Xing Kang Xu Weishan Li School of Chemistry and Environment South China Normal UniversityGuangzhou 510006China National and Local Joint Engineering research Center of MPTES in High Energy and Safety LIBs Engineering Research Center of MTEES(Ministry of Education)and Key Lab.of ETESPG(GHEI)South China Normal UniversityGuangzhou 510006China electrochemistry Branch Sensor and Electron Devices DirectoratePower and Energy DivisionU.S.Army Research LaboratoryAdelphi MD 20783USA

Lithium-rich oxide is one of the most promising cathodes that meet high energy density requirement for batteries of the future, but its phase transformation from layer to spinel structure caused by the lattice instability presents severe challenge to cycling stability and the actually accessible capacity. The currently available approaches to suppress this undesired irreversible process often resort to limit the high voltages that lithium-rich oxide is exposed to. However, cycling stability thus improved is at the expense of the eventual energy output. In this work, we identified a new mechanism that is directly responsible for the lithium-rich oxide phase transformation and established a clear correlation between the successive consumption of Li+on anode due to incessant interphase repairing and the over-delithiation of lithium-rich oxide cathode. This new mechanism enables a simple but effective solution to the cathode degradation, in which an electrolyte additive is used to build a dense and protective interphase on anode with the intention to minimize Li depletion at cathode. The application of this new interphase effectively suppresses both electrolyte decomposition at anode and the phase transformation of lithium-rich oxide cathode, leading to high capacity and cycling stability.

关键词： electrolyte additive graphite-based battery lithium-rich oxide cathode phase transformation suppression

Preparation and Characterization of New Antibacterial Polyester Composites

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材料科学与工程（中英文A版） 2011年第6期1卷 865-868页

作者： Azadeh Azadbakht Amir Reza Abbasi electrochemistry research lab Department of Chemistry Faculty of Science Khorramabad Branch Islamic Azad UniversityKhorramabad Iran

Hierarchical pomegranate-structure design enables stress management for volume release of Si anode

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Journal of Materials Science & Technology 2023年第26期157卷 1-10页

作者： Fang Di Zhenxing Wang Chong Ge Lixiang Li Xin Geng Chengguo Sun Haiming Yang Weimin Zhou Dongying Ju Baigang An Feng Li Key laboratory of Energy Materials and electrochemistry Liaoning Province School of Chemical EngineeringUniversity of Science and Technology LiaoningAnshan 114051China Institute of Metal research Chinese Academy of SciencesShenyang 110016China Hainan Provincial Key lab of Fine Chemistry School of Chemical Engineering and TechnologyHainan UniversityHaikou 570228China Jihua laboratory Guangdong ProvinceFoshan 528200China

Si is a promising anode material for lithium-ion batteries owing to its high theoretical ***-ever,large stress during(de)lithiation induces severe structural pulverization,electrical contact failure,and unstable solid-electrolyte interface,which hampers the practical application of Si ***,a Si-based anode with a hierarchical pomegranate-structure(HPS-Si)was designed to modulate the stress variation,and a sub-micronized Si-based sphere was assembled by the nano-sized Si nanospheres with sub-nanometer-sized multi-phase modification of the covalently linked SiO_(2-x),SiC,and *** sub-micronized HPS-Si stacked with Si nanospheres can avoid agglomerates during cycling due to the high surface energy of ***,the reasonable pore structure from SiO_(2) reduction owing to density difference is enough to accommodate the limited volume *** Si spheres with a size of about 50 nm can prevent ***_(2-x),and SiC as flexible and rigid layers,have been syner-gistically used to reduce the surface stress of conductive carbon layers to avoid *** covalent bonding immensely strengthens the link of the modification with Si nanospheres,thus resisting stress ***,a full cell comprising an HPS-Si anode and a LiCoO_(2) cathode achieved an energy density of 415 Wh kg^(-1) with a capacity retention ratio of 87.9%after 300 cycles based on the active *** is anticipated that the hierarchical pomegranate-structure design can provide inspiring insights for further studies of the practical application of silicon anode.

关键词： Stress management Silicon anode Hierarchical structure Covalent bonding Volume release

Emerging biosensors in detection of natural products

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Synthetic and Systems Biotechnology 2020年第4期5卷 293-303页

作者： Firoozeh Piroozmand Fatemeh Mohammadipanah Farnoush Faridbod Pharmaceutical Biotechnology lab Department of Microbial BiotechnologySchool of Biology and Center of Excellence in Phylogeny of Living OrganismsCollege of ScienceUniversity of Tehran14155-6455TehranIran Center of Excellence in electrochemistry School of ChemistryCollege of ScienceUniversity of TehranTehranIran

Natural products(NPs)are a valuable source in the food,pharmaceutical,agricultural,environmental,and many other industrial *** beneficial properties along with their potential toxicities make the detection,determination or quantification of NPs essential for their *** advanced instrumental methods require time-consuming sample preparation and *** contrast,biosensors allow rapid detection of NPs,especially in complex media,and are the preferred choice of detection when speed and high throughput are ***,we review diverse biosensors reported for the detection of *** emerging approaches for improving the efficiency of biosensors,such as microfluidics,nanotechnology,and magnetic beads,are also *** simultaneous use of two detection techniques is suggested as a robust strategy for precise detection of a specific NP with structural complexity in complicated *** parallel detection of a variety of NPs structures or biological activities in a mixture of extract in a single detection phase is among the anticipated future advancements in this field which can be achieved using multisystem biosensors applying multiple flow cells,sensing elements,and detection mechanisms on miniaturized folded chips.

关键词： Natural products Biosensor Rapid detection Molecular biosensors Nanomaterials

Novel Ba_(0.5)Sr_(0.5)Fe_(0.8)Zn_(0.2)O_(3-δ) membranes for POM

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Chinese Chemical Letters 2009年第2期20卷 250-252,F0003页

作者： Hui Xia Luo Ling Hui Yu Xin Zhi Chen Hai Hui Wang Jtirgen Caro The Key lab of Enhanced Heat Transfer and Energy Conservation of Chinese Ministry of Education School of Chemistry & Chemical Engineering South China University of Technology Guangztwu 510640 China Institute of Physical Chemistry and electrochemistry Leibniz University Hannover Callinstr. 3-34 D-30179 Hannover Germany

A novel cobalt-free perovskite based on Ba0.5Sr0.5Fe0.8Zn0.2O3-δ （BSFZ） were prepared by EDTA-citric acid method. The lattice constants of the BSFZ perovskite were characterized by in situ high-temperature X-ray diffraction （HTXRD）. The thermal expansion coefficient of BSFZ is 10.5×10^-6 K^-1, which is lower than that of cobalt-based perovskite materials. The BSFZ membrane was also used to construct reactors for the partial oxidation of methane （POM） to syngas. Results show that the BSFZ membrane can be operated for the POM reaction for more than 100 h without any fractures. The CO selectivity of 97% is obtained. The steady oxygen permeation flux reaches around 2.5 mL/min cm^2 during POM reaction.

关键词： Membrane Oxygen separation Mixed conductor Perovskite POM