Shou Gang Chen

Fabrication of Highly Ordered Titania Nanotubes in Viscous Organic Electrolytes

The TiO2 nanotubes with a highly ordered structure on titanium were grown by a self-organized electrochemical anodization with viscous organic electrolytes containing small additions of fluorides as the supporting electrolyte. The structure and composition of the as-anodized nanotubes were characterized by field emission scanning electron microscopy. The formation mechanism of the nanotubes was discussed.

Study on the Surface Modification and Dispersion of Multi-Walled Carbon Nanotubes

The potential applications of carbon nanotubes are reviewed in this paper. With the development of modification and purification of carbon nanotubes, the scope of carbon nanotubes applications is expanded greatly. This paper pays attention to the modification and dispersion of multi-walled carbon nanotube (MWNTs). The results show that the acid treated MWNTs are highly pure and the surface of treated MWNTs is rough comparably. In addition, treated MWNTs are homogeneously dispersed without any surfactants present in organic solvents of acetone, toluene, and ethanol; the dispersive stability of carboxylic MWNTs dispersions is investigated over 2 weeks.

Hydrothermal Synthesis of BaTiO3 Nanotubes on Ti Substrates

A novel, low-temperature two-step synthesis method for producing BaTiO3 thin films patterned in the form of nanotubes on Ti substrates is reported. Firstly, the Ti substrate is anodized to produce a surface layer of amorphous TiO2 nanotube arrays. Secondly, the anodized substrate is subjected to hydrothermal treatment in aqueous Ba(OH)2, where the nanotube arrays serve as templates for their hydrothermal conversion to single-crystal BaTiO3 thin film. This opens the possibility of tailoring the nanotube arrays and their combinations in the hydrothermal bath, to produce ordered, patterned thin film structures of various Ti containing ceramics.

A Facile Method of Surface Modification Based on the Adhesive Behavior of Poly(dopamine) on Copper

A 3, 4-dihydroxyphenethylamine (dopamine) polymer film has been prepared on copper surface from 2.0g/L dopamine solution in tris(hydroxymethyl)aminomethane hydrochloride (Tris-HCl) buffer solution at pH 8.5 by a simple solution-immersion method. The dopamine self-polymerized and adhered to the copper surface firmly in aqueous environment. The film surface was evaluated through SEM, EDS, XPS and contact angle measurement. The results have shown that the film was indeed formed on copper surface. And this research offers a versatile approach for the surface modification.

Electronic Structure of Bimetallic FemAln (m+n=6) Clusters

Theoretical study on the electronic structure of small FemAln(m+n=6) clusters has been carried out at the BPW91 level, and the electronic structures, binding energy and vertical ionization potential of clusters were evaluated. For the stable clusters, the iron atoms gather together and form a maximum of Fe-Fe bonds, and the aluminum atoms locate around Fe core with a maximum of Fe-Al bonds. The binding energy and vertical ionization potential show that the Fe5Al, Fe4Al2 and Fe3Al3 clusters have higher stability, which results provide insight into the properties of iron-aluminides can be obtained from a finite size cluster model.

Analytical Characterization and Corrosion Behavior of Non-Functional Bis-Silane Pre-Treated Carbon Steel Substrates

The present work aims at studying the corrosion resistance of carbon steel substrates pre-treated with bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) solutions. The corrosion behavior of the pre-treated substrates during immersion in seawater was assessed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The analytical characterization of the silane films was performed by scanning electron microscopy (SEM). The results show that the pre-treatments based on silanes provide good corrosion protection of carbon steel substrates and the bis-silane film has good adhesion properties.

Microbially Influenced Corrosion of Copper by Marine Bacterium Vibrio natriegens

The microbially influenced corrosion of copper by marine bacterium Vibrio natriegens (V. natriegens) was investigated using surface analysis (atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). AFM images corroborated the results from the EIS models which show biofilm attachment over time. The electrochemical results showed that the corrosion of copper was accelerated in the presence of V. natriegens based on the decrease in the resistance of the charge transfer resistance (Rct) obtained from EIS.

First-Principles Study of Lithium Absorption in Boron- or Silicon-Doped Single-Walled Carbon Nanotubes

The lithium absorption energies and electronic structures of boron- or silicon-doped single-walled carbon nanotubes (SWCNT) were investigated using first-principles calculations based on the density-functional theory. As B and Si doping carbon nanotubes, the lithium atom adsorption energies decrease. The effects of B and Si doping are different on the lithium atomic adsorption. B-doping forms an electron-deficient structure in SWCNT. While the Si-doping forms a highly reactive center. The calculations suggest that boron- and silicon-doping in SWCNT will improve Li absorption performance.

Electronic Structure Study of Metal Complex {1,1’-[ o-Phenylenebis(nitrilomethylidyne)]di-2-naphtholato}Copper(II)

The complex {1,1’-[ o-phenylenebis (nitrilomethylidyne) ] di-2-naphtholato} copper(II) was optimized by the DFT method at B3LYP/LANL2DZ level, and the frontier molecular orbitals, natural bond orbitals, nonlinear optical properties and Mülliken charge population of the optimized complex were exploited and analyzed. The calculated results show that the complex has stable structure and it keeps some potential applications in optic materials field.

The Doping of Ag+ Enhanced the Antibiocorrosive Effect of Titania in Seawater under Visible Light

Sol-gel TiO2 thin films undoped and doped with Ag-ions have been formed on 304ss by dip-coating method respectively. The Ag/TiO2 films are compact and have anatase phase with stable crystal structure and have a thickness of 50 nm approximately. The bactericidal rate of the Ag/TiO2 film against sulfate-reducing bacteria (SRB) strains reaches 97.1% when doping Ag+ with a percentage of 3%. The analysis of potentiodynamic polarization curves illustrates Ag/TiO2 film decreases the corrosion rate obviously.