Materials Science and Engineering Commons^™

Surface Pre-Treatments And Fabrication Of Highly Ordered Anodic Aluminum Oxide Nanopores At Room Temperature, Sampath Chennuri

Electrical & Computer Engineering Theses & Dissertations

The object of this work is to develop a novel approach to fabricate model membranes of well-defined and well aligned nanostructured materials in a robust environment. The main focus is on electrochemical synthesis, involving anodic oxidation of high purity aluminum sheets to form porous oxide films. Alumina films were prepared by anodizing highly pure aluminum (99.999%) in acidic electrolytes. Anodization parameters (current density, temperature, applied voltage, anodization time and electrolyte concentration) were selected with respect to the electrolyte used.

The primary challenge in nanotechnology is the creation of nanometer-scaled objects with as narrow a size distribution as possible for a …

Electrocatalytic Oxidation Of Salicylic Acid At Novel Gold Nanoparticle-Modified Glassy Carbon Electrode, Yan-Ping Cui, Chang-Zhu Yang, Jian Huang, Wen-Hong Pu, Jing-Dong Zhang

Journal of Electrochemistry

A gold nano-particles modified glassy carbon electrode(GNP/GCE) was prepared by the"seed-mediated gold nano-particles growth method".Field emission scanning electron microscopy,ultraviolet-visible(UV-vis) spectroscopy analysis and electroalaylsis were employed to study the morphology and electrochemical performances.The resulting electrode showed excellent electro-catalytic activity toward the oxidation of salicylic acid and the response sensitivity was 1.8 fold than that obtained on GCE.Good linear relationship was obtained between response current and salicylic acid concentration in the range of 5.0 × 10^-7 ~8.0 × 10^-5 mol/L,which could be used in the detection of trace salicylic acid.

Design And Fabrication Of The High Efficient Platinum-Nanoporous Gold Catalysts, Zhao-Na Liu, Jin-Tao Zhang, Fang Tian, Peng-Peng Liu, Hou-Yi Ma, Yi Ding

Journal of Electrochemistry

The nanoporous gold(NPG) electrodes with uniform pore sizes and ligaments were prepared by using a simple dealloying method.The as-prepared NPG showed high catalytic activity towards the oxidation of formic acid and formaldehyde.After tiny amount of platinum was deposited onto the NPG substrate,not only the structure stability of NPG was greatly improved,but also the Pt-Au bimetallic catalysts displayed the better catalytic activity and the stronger poison resistance towards the electrooxidation of small organic molecules than the bulk platinum due to synergistic effect between Au and Pt compositions.

Electrochemical Synthesis, Characterization And Fluorescence Property Of Nano Na2Sif6, Guo-Xu Qin, Xin-Jun Wan, Xi-Mei Yuan, Dao-Bao Chu

Journal of Electrochemistry

The nano TiO₂ film was prepared by sol-gel process and characterized with X-ray diffraction(XRD) and scanning electron microscope(SEM).It was found that the average size of pore diameter was about 80 nm for the nano TiO₂ film.The Nano Na₂SiF₆ was synthesized by electrochemical deposition on the nanoporous film electrode and characterized with XRD and transmission electron microscope(TEM).The result showed that the average size of nanoparticle was 20 nm for the nano Na₂SiF₆.The fluorescence property of nano Na₂SiF₆ was also studied briefly.The result indicated that the nano Na₂SiF …

Corrosion Inhibition Of Self-Assembled Films On Iron By Electrochemical Impedance Spectroscopy, Yuan-Yuan Feng, Shen-Hao Chen, Juan-Juan Zhou, Wen-Juan Guo

Journal of Electrochemistry

The self-assembled films of tetradecylamine were formed on iron surface, and the inhibition ability of which for iron corrosion in 0.5 mol/L H₂SO₄ solutions was studied by electrochemical impedance spectroscopy technique. Results indicated that longer immersion time would result in stronger inhibition ability of the films. The maximal inhibition efficiency(IE) of the tetradecylamine films was 68.7%. When the tetradecylamine films were modified by dodecylthiol, the mixed films became denser and more stable, thus the inhibition ability increased remarkably. The η of the mixed films increased to 78.2%.

Study On Electrocatalytic Oxidation Of Salbutamol At Carbon Nanotubes Modified Electrode, Ying-Liang Wei, Lu-Ping Zhang, Chen Shao, Hui Feng, Xian-Li Li

Journal of Electrochemistry

The multi-wall carbon nanotubes(MWNT) were dispersed successfully into water in the presence of dihexadecyl hydrogen phosphate(DHP) and a stable well-distributed suspension.A was formed sensor based on the multi-carbon nanotubes film coated glassy carbon electrode was developed.The electrochemical response of salbutamol was studied by square wave voltammetry.The oxidation peak potential of salbutamol at the modified electrode was observed at 0.604 V,which shifted about 40 mV negatively.The peak current increased 4.5 folds,in contrast to that at a bare electrode.Under optimal measurement conditions,there was a good linear relationship between the peak current(Ipa) and salbutamol concentration(C) in the range from 8.3 × 1 0 …

Preparation And Photoelectrochemical Properties Of Fe-Doped Tio2 Nanotube Arrays, Jing Li, Lan Sun, Hui-Fang Zhuang, Cheng-Lin Wang, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

The Fe-doped TiO₂ nanotube arrays were fabricated in Fe(NO₃)₃-HF mixing solutions by electrochemical anodic oxidation method,and characterized by FESEM,Raman,XPS and DRS.The effect of Fe concentratiions on photoelectrochemical property of the arrays was also investigated.The diameters and lengths of Fe-doped TiO₂ nanotube arrays were 50~90 nm and about 200 nm,respectively.Compared with the undoped TiO₂ nanotube arrays,the absorption edge of Fe-doped TiO₂ nanotube arrays appeared red shifting.The more Fe content,the larger red shifting,in addition,the photocurrent of Fe-doped TiO₂ nanotube arrays increased obviously.

Cyclic Voltammetry And In Situ Ftir Studies Of Cyanide Adsorption On Nanostructured Au Film Electrode In Alkaline Solutions, Chun-Hua Zhen, Chun-Jie Fan, Shi-Gang Sun

Journal of Electrochemistry

The adsorption of cyanide(CN^-) on electrodes of nanometer scale thin film of gold supported on glassy carbon(nm-Au/GC) in alkaline solutions were investigated using cyclic voltammetry and in situ FTIR spectroscopy.It has revealed that the electrodeposited nanostructured Au thin film exhibited AIREs(abnormal infrared effects) for CN^-adsorption,which manifested 3 nonlinear IR spectral features: inversion of the direction of CN^-band,enhancement of IR absorption of adsorbed CN-species(about 39.2 folds) and increase in the FWHM(full width at half maximum) of CN^-band.

Carbon Nanotube Array Electrodes Based Supercapacitors With 3.5v Working Voltage, Hao Zhang, Gao-Ping Cao, Yu-Sheng Yang, Zhen-Nan Gu, Bin Xu, Wen-Feng Zhang

Journal of Electrochemistry

The carbon nanotube arrays(CNTA) were grown directly on the substrates of Ta and stainless steel by chemical vapor deposition.The button-like supercapacitors were fabricated based the CNTA electrodes.The electrochemical performance of CNTA based supercapacitors presentsed high working voltage(3.5 V),long cycle life,and good rate capability.The power and energy densities are were 928 kW·kg^-1 and 19 Wh·kg^-1,respectively(based on the mass of CNTA).

Structure And Property Of Molecular Self-Assembled Membrane With Zirconium Ion, Tian-De Wang, Rong Wang, Xia-Qin Wu, Zhi-Gang Guo, Wei-Wei Ji

Journal of Electrochemistry

According to the complex interaction between dodecyl phosphonate and stainless steel surface as well as the zirconium ion,the self-assembled monolayer and double-layer dodecyl phosphonate modified 304 type stainless steel electrode were prepared.The electrodes were characteristiced by static contact angles and electrochemical polarization methods.The results suggested that the double-layer modified stainless steel electrode had better corrosion inhibition effect than the monolayer modified electrode.

Quick Tester With Usb Interface For The Corrosion Protection Properties Of Organic Coating, Xiang-Dong Zhuo, Chang-Jian Lin

Journal of Electrochemistry

According to the principle of multiple dynamic potential scaning polarization,a quick tester with USB interface for the fast study of corrosion resistance properties of organic coating/ metal system has been developed.This tester is portable,facile,practical,and has a strong function for data collection and data treatment.It is not only suitable for the accelerated test in laboratory,but also for the quick test and evaluation to the corrosion resistance of the organic coating/metal system in industrial spots.

An Ultrahigh Vacuum Complementary Metal Oxide Silicon Compatible Nonlithographic System To Fabricate Nanoparticle-Based Devices, Arghya Banerjee, Biswajit Das

Electrical & Computer Engineering Faculty Research

Nanoparticles of metals and semiconductors are promising for the implementation of a variety of photonic and electronic devices with superior performances and new functionalities. However, their successful implementation has been limited due to the lack of appropriate fabrication processes that are suitable for volume manufacturing. The current techniques for the fabrication of nanoparticles either are solution based, thus requiring complex surface passivation, or have severe constraints over the choice of particle size and material. We have developed an ultrahigh vacuum system for the implementation of a complex nanosystem that is flexible and compatible with the silicon integrated circuit process, thus …

In Situ Measurement Of Chloride Concentration And Ph Distribution In The Crevice During The Crevice Corrosion Of Copper Electronic Board, Min Zhang, Xiang-Dong Zhuo, Chang-Jian Lin

Journal of Electrochemistry

Although the crevice corrosion of metals had been extensively studied in the past years,it remained lack of direct experimental information of the micro chemical environments and electrochemical conditions inside the corroding crevice.The distribution of chloride concentration and local pH in the occluded area are the most crucial factors in development of crevice corrosion.The array probes in one dimension of Ag/AgCl and IrO₂ array were developed in this work to in situ follow the distribution of chloride concentration and local pH in the occluded area during the crevice corrosion propagation.Based on a designed simulated crevice corrosion system in 0.5mol/L NaCl …

A Study On Supercapacitor Based On Aligned Carbon Nanotubes, Xiao-Yan Ye, Yan-Zhi Wang, Hai-Yan Song, Zhuo Sun, Pin-Gang He, Yu-Zhi Fang

Journal of Electrochemistry

Large scale vertically aligned carbon nanotubes(ACNTs) with uniform length and diameter were prepared by the pyrolysis of iron(Ⅱ) phthalocyanine at low pressure.The ACNTs were activated by electrolyte-activation,acid-activation or electrochemical activation.The performance of the capacitor based on activated ACNTs was characterized by cyclic voltammograms which was of rectangular shape,impedence spectroscopy in which the phase is above 80° and the result specific capacitance was 16～32 F/g,which suggest that the ACNTs are the promising material for the supercapacitor.

Morphologies And Kinetics Of A Dewetting Ultrathin Solid Film, Mikhail Khenner

Mathematics Faculty Publications

The surface evolution model based on geometric partial differential equation is used to numerically study the kinetics of dewetting and dynamic morphologies for the localized pinhole defect in the surface of the ultrathin solid film with the strongly anisotropic surface energy. Depending on parameters such as the initial depth and width of the pinole, the strength of the attractive substrate potential and the strength of the surface energy anisotropy, the pinhole may either extend to the substrate and thus rupture the film, or evolve to the quasiequilibrium shape while the rest of the film surface undergoes phase separation into a …

Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Mikhail Khenner

Mathematics Faculty Publications

Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequency-amplitude domain where the parametric and shear-flow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description …

Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev

Mathematics Faculty Publications

Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequency-amplitude domain where the parametric and shear-flow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description …

Enhanced Stability Of A Dewetting Thin Liquid Film In A Single-Frequency Vibration Field, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev

Mathematics Faculty Publications

Dynamics of a thin dewetting liquid film on a vertically oscillating substrate is considered. We assume moderate vibration frequency and large (compared to the mean film thickness) vibration amplitude. Using the lubrication approximation and the averaging method, we formulate the coupled sets of equations governing the pulsatile and the averaged fluid flows in the film, and then derive the nonlinear amplitude equation for the averaged film thickness. We show that there exists a window in the frequency-amplitude domain where the parametric and shear-flow instabilities of the pulsatile flow do not emerge. As a consequence, in this window the averaged description …

Morphologies And Kinetics Of A Dewetting Ultrathin Solid Film, Mikhail Khenner

Mathematics Faculty Publications

The surface evolution model based on geometric partial differential equation is used to numerically study the kinetics of dewetting and dynamic morphologies for the localized pinhole defect in the surface of the ultrathin solid film with the strongly anisotropic surface energy. Depending on parameters such as the initial depth and width of the pinole, the strength of the attractive substrate potential and the strength of the surface energy anisotropy, the pinhole may either extend to the substrate and thus rupture the film, or evolve to the quasiequilibrium shape while the rest of the film surface undergoes phase separation into a …

Nano Quasicrystal Formation And Local Atomic Structure In Zr––Pd And Zr––Pt Binary Metallic Glasses, Junji Saida, Takashi Sanada, Shigeo Sato, Muneyuki Imafuku, Chunfei Li, Akihisa Inoue

Center for Electron Microscopy and Nanofabrication Publications and Presentations

Formation of the nanoscale icosahedral quasicrystalline phase (I-phase) in the melt-spun Zr₇₀Pd₃₀ and Zr₈₀Pt₂₀ binary metallic glasses were reported. Local atomic structure in the glassy and quasicrystal (QC)-formed states were also analyzed by XRD and EXAFS measurements in order to investigate the formation mechanism of QC phase. The distorted icosahedral-like local structure can be identified around Zr atom in the Zr₇₀Pd₃₀ metallic glass. In the QC formation process, a change of local environment around Zr is detected, in which the approximately one Zr atom substitutes for one Pd atom. In contrast, …

A New Method Of Synthesizing Black Birnessite Nanoparticles: From Brown To Black Birnessite With Nanostructures, Shizhi Qian, Marcos A. Cheney, Pradip K. Bhowmik, Sang W. Joo, Wensheng Hou, Joseph M. Okoh

Mechanical Engineering Faculty Research

A new method for preparing black birnessite nanoparticles is introduced. The initial synthesis process resembles the classical McKenzie method of preparing brown birnessite except for slower cooling and closing the system from the ambient air. Subsequent process, including wet-aging at 7◦C for 48 hours, overnight freezing, and lyophilization, is shown to convert the brown birnessite into black birnessite with complex nanomorphology with folded sheets and spirals. Characterization of the product is performed by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), and N2 adsorption (BET) techniques. Wet-aging and lyophilization times are shown to …

Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications, Biswajit Das

Transmutation Sciences Materials (TRP)

Advanced transmutation systems require structural materials that are able to withstand high neutron fluxes, high thermal cycling, and high resistance to chemical corrosion. The current candidate materials for such structures are ferritic and ferritic-martensitic steels due to their strong resistance to swelling, good microstructural stability under irradiation, and the retention of adequate ductility at typical reactor operating temperatures.

In parallel, lead-bismuth eutectic (LBE) has emerged as a potential spallation target material for efficient production of neutrons, as well as a coolant in the accelerator system. While LBE has excellent properties as a nuclear coolant, it is also highly corrosive to …

Determination Of Malathion Based On Carbon Nanotubes Modified Electrode Incorporating Acetylcholinesterase, Lu Zhang, Yao-Dong Zhang, Hong-Lan Qi

Journal of Electrochemistry

A biosensor for determination of organophosphorus pesticide based on the acetylcholinesterase and multi-wall carbon nanotubes modified electrode is fabricated.Under the optimal conditions,the chronoamperometric current at +0.70V(vs.SCE) increased linearly with the concentration of malathion in the range from 6.0×10^-10 to 6.0×10^-9 mol·L^-1 with a detection limit of 1.0×10^-10 mol·L^-1.The recoveries of malathion in lake water is 97% to 105% determinated by this method.

Study On Electrochemical Impedance Spectroscopy Of Carbon Steel Eroded In Methyldiethanolamine Solution, Dong-Ping Wei, Rong-Zong Hu, Dan-Mei Pan, Wei-Xiong Huang, Rui Dong

Journal of Electrochemistry

Corrosion behavior of carbon steel in methyldiethanolamine(MDEA) solution was investigated by Electrochemical Impedance Spectroscopy(EIS).The results were showed that the corrosion rate of carbon steel in solution containing dissolved oxygen is higher than that in solution removed of dissolved oxygen before cathodic activation.They were reversed after cathodic activation.The corrosion rate is increased at first and then decreased when the concentration of MDEA is increased in the blank solutions.In the simulated solutions containing quantities of!heat-stable salts(HSS),the corrosion rate is decreased monotonously with increase of the MDEA concentration.As anodic polarization potential is increased,the EIS of carbon steel in HSS simulated solution showed characteristics …

Growth Mechanism And Morphology Of Electrodeposited Micro-Nanocrystalline Iron, Qiao-Xin Zhang, Jia-Ming Zhang, Li-Ning Yang

Journal of Electrochemistry

Effects of current density,reaction temperature,electrolyte concentration and surfactant on the electrochemical deposition of micro-nanocrystalline iron were studied.Morphologies and structures of the samples were characterized by SEM and XRD,the results showed that the electrodeposits is slice α-Fe under little current and the density,lower temperature and higher concentration,and the dentritic α-Fe is under opposite conditions,but the influence from surfactant is unconsicously.Moreover,the growth mechanism of the electrodeposits was also analysed here.

Fabrication And Charaterization Of Nitrogen-Doped Tio2 Nanotube Array And Its Visible Light Activity, Hui-Fang Zhuang, Yue-Kun Lai, Jing Li, Lan Sun, Chang-Jian Lin

Journal of Electrochemistry

Nitrogen-doped TiO₂ nanotube array was fabricated by an electrochemical anodic oxidation followed a wet process.XPS result indicates that the nitrogen atoms were doped into lattice of TiO₂ nanotubes.The UV-Vis spectra show that the photoabsorption of N-doped TiO₂ nanotube array film is enhanced in the visible light region.Compared with the TiO₂ nanotube array film,the N-doped TiO₂ nanotubes exhibite a higher photocatalytic activity which is evaluated by the decomposition rate of methyl orange using the tungsten-halogen lamp as light source.

Electrocatalytic Oxidation Of Methanol At The Nano Ni-B Amorphous Alloy Powdermicroelectrode, Yi-Xiong Zheng, Shi-Bing Yao, Shao-Min Zhou

Journal of Electrochemistry

Electrocatalytic oxidation of methanol at the nano Ni-B amorphous alloy powder-microelectrode in alkaline media was studied by using cyclic voltammetry.Compared to the highly preferred orientation(220) nickel electrode,The onset potential of methanol electrooxidation at the nano Ni-B microelectrode is negatively shifted about 0.04V,and the current density is increased approximately by 2 orders of magnitude.Thus,the nano Ni-B microelectrode has very strong electrocatalytic activity for the oxidation of methanol.The kinetic parameters were determined with the steady polarization curves.The results show that the rate constants for both the oxidation of Ni(Ⅱ) to Ni(Ⅲ) and the reduction of Ni(Ⅲ) to Ni(Ⅱ) at the nano Ni-B …

The Syntheses And Electrochemical Performance Of Nano-Mno2 For Supercapacitor, Jun Ma, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Nano-manganese dioxide were prepared by two different methods which are low temperature solid reaction and chemical deposition.The products were characterized by XRD,SEM,BET and constant current charge-discharge tests.The result shows that there is a close relationship between specific capacitance and BET surface areas.Meanwhile the specific capacitance was impacted little by the structure of the nano-manganese dioxides.However,the product performance of high rates,was influenced by structure,the higher rate can be obtained with the more perfect crystal structure.

Catalysis Of Nano Tio2 For Horseradish Peroxidase, Ya-Qi Zhu, Hai Wu, Hiu Liu, Jie Ma

Journal of Electrochemistry

Horseradish peroxidase immobilized on the surface of titanium dioxide nanoparticles and nanotube modified glassy carbon electrode.The HRP direct electron transfer reaction was compared between TiO₂ nanoparticles and nanotube GC electrode.The results demonstrated that the HRP on TiO₂ nanotube /GC electrode could catalyze electron exchange reaction between electroactivity center of HRP and electrode.And the research of antibody labeled HRP provides a selected signal for antibody-antigen immunoassay.

Determination Of Ddopamine And Ascorbate On Gold Nanoparticle And 4,4-Bis (Methanethiol) Biphenyl (Mtp) Self-Assembled Monolayer Modified Gold Electrode, Hai-Yan Wang, Peng Liu, Ye Wang, Bao-Kang Jin

Journal of Electrochemistry

A new approach to construct an ampermetric biosensor was described.The 4,4-bis(methanethiol)biphenyl(MTP)is adsorbed on to a bare gold electrode to make self-assembled monolayers(MTP/Au SAMs).Then electrodeposited 2mg/mL HAuCl₄ at-200 mV,NG/MTP/Au electrode was prepared.When a differential pulse voltammetric(DPV)technique was used,the peak separation between DA and AA is 155 mV.Hence,the selective determination of dopamine(DA)and ascorbate(AA)in the binary mixture system can be performed.Under the chosen conditions,the peak currents are correspondent linearly to the concentrations of DA and AA in the range of 5.0×10^-7~1×10^-4 mol·L^-1 and 3.5×10^-6~1.0×10^-3mol·L^-1,respectively.The correlation coefficients were 0.998.The detection limit were 1.5×10 …