Xiaogang Guo

Effects of Surfactants on High Regularity of 3D Porous Nickel for Zn2

Three-dimensional porous nickel (3D-PN) film with large specific surface area () and high porosity has been successfully prepared by hydrogen bubble dynamic template (HBDT) method. This work presents the effects of PEG 10000 and 1,4-butynediol as new additive combination on surface morphology of the PN film. Meanwhile, the application of 3D-PN in Zn2

An in-line Mach-Zehnder Interferometer Using Thin-core Fiber for Ammonia Gas Sensing With High Sensitivity

Ammonia is an important indicator among environmental monitoring parameters. In this work, thin-core fiber Mach-Zehnder interferometer deposited with poly (acrylic acid) (PAA), poly (allyamine hydrochloride) (PAH) and single-walled carbon nanotubes (SWCNTs-COOH) sensing film for the detection of ammonia gas has been presented. The thin-core fiber modal interferometer was made by fusion splicing a small section of thin-core fiber (TCF) between two standard single mode fibers (SMF). A beam propagation method (BPM) is employed for the design of proposed interferometer and numerical simulation. Based on the simulation results, interferometer with a length of 2 cm of thin-core fiber is fabricated and experimentally studied. (PAH/PAA)2 + [PAH/(PAA + SWCNTs-COOH)]8 film is deposited on the outer surface of thin-core fiber via layer-by-layer (LbL) self-assembly technique. The gas sensor coated with (PAH/PAA)2 + [PAH/(PAA + SWCNTs-COOH)]8 film towards NH3 gas exposure at concentrations range from 1 to 960 ppm are analyzed and the sensing capability is demonstrated by optical spectrum analyzer (OSA). Experimental results show that the characteristic wavelength shift has an approximately linear relationship in the range 1–20 ppm, which is in accordance with the numerical simulation. Thus, this paper reveals the potential application of this sensor in monitoring low concentration NH3 gas.

A novel route for preparation of superhydrophobic multi-scale films on stainless steel via etching and electrophoretic deposition process

Abstract Superhydrophobic aluminium films have been successfully fabricated on steel substrate via chemical etching and electrophoretic deposition processes, followed by 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (FAS) modification. The resultant surface is investigated by field emission scanning electron microscope (FESEM), atomic force microscopy, X-ray diffraction and Fourier-transform infrared spectroscopy (FTIR). The results show a hierarchical multi-scale structure and a grafted FAS film with low surface energy on the resultant sample surface, which confers excellent superhydrophobicity with a water contact angle of 168.9° and a sliding angle of ca. 1.5°. Such a superhydrophobic steel substrate shows an excellent anti-adhesion behaviour and anti-corrosion property against corrosive liquids. Furthermore, it also holds its superhydrophobicity even after a long-time exposure to air. Our work may provide a novel and facile fabrication route to prepare other functional superhydrophobic films on metal substrate for various applications.

A comprehensive investigation on adsorption of Ca (II), Cr (III) and Mg (II) ions by 3D porous nickel films.

The present study reports the removal of Ca (II), Cr (III), Mg (II) ions from aqueous solution using 3D-porous nickel films (3DNFs) as a novel adsorbent material prepared by hydrogen bubble dynamic template (HBDT) method at room temperature. The structure morphology and the phase constitution of 3DNFs were characterized by FESEM, EDS and XRD. Adsorption process of Ca (II), Cr (III), Mg (II) ions was fast as the equilibrium was established within 30min, and the maximum adsorption at equilibrium was 44.1mg/g, 46.4mg/g and 32.7mg/g, respectively. The adsorption kinetics well fitted using a pseudo second-order kinetic model. The adsorption isotherm data of all the three metals fit well the Langmuir and Freundlich adsorption isotherm model. It was found out that kinetics of adsorption varies with initial concentration of metal ions. Thermodynamic parameters (i.e., the standard Gibbs free energies (ΔG), enthalpy change (ΔH), standard entropy change (ΔS)) were also evaluated. Thermodynamic analysis indicated that a high temperature is favored for the adsorption of metal ions by 3DNFs. These results suggest that 3DNFs have good potential application in effective adsorption of metal ions with satisfactory results.

Facile one-step chemical deposition process to fabricate superhydrophobic porous Cu films on Al alloy surface

Abstract Herein, we demonstrated a facile one-step fabrication strategy combining both chemical deposition and self-assembly of stearic acid for the fabrication of superhydrophobic porous Cu films on the Al substrates. The scanning electron microscopy and white light interferometer showed that the multi-scale porous structures comprising micron-sized pores and nano-sized fishbone-like dendrites were formed on the sample. X-ray diffraction and Fourier-transform infrared spectrophotometer revealed the deposition of Cu and the grafting process of stearic acid on the films. In addition, the formation mechanism of the superhydrohobic surface was explained, and the processing conditions were investigated to determine their effects on the wettability. The resultant sample revealed superhydrophobicity with a water contact angle of 159 ± 1°, a sliding angle of ca. 4° and great bouncing behaviour of water droplets. Moreover, such a surface exhibited a stable superhydrophobicity even after six weeks of ambient air exposure.

Investigation on Two Compounds of O,O’-dithiophosphate Derivatives as Corrosion Inhibitors for Q235 Steel in Hydrochloric Acid Solution

Abstract In this work, the O,O’-dithiophosphate derivatives of S-4-methylbenzyl-O,O’-di(phenyl) dithiophosphate (Inhi-Ph) and S-4-methyl benzyl-O,O’-di(4-bromophenyl) dithiophosphate (Inhi-BrPh) were synthesized and characterized by elemental analysis, FT-IR, 1H, 13C and 31P NMR. Meanwhile, the corrosion inhibition of Q235 steel in HCl solution by synthesized inhibitors was evaluated by weight loss and electrochemical measurements. Measurement results indicate that the two inhibitors of Inhi-Ph and Inhi-BrPh are mixed-type inhibitor, the inhibition efficiency increase with inhibitor concentration increasing, decrease with HCl concentration and temperature increasing. The adsorption of Inhi-Ph and Inhi-BrPh on Q235 steel surface obeys Langmuir isotherm, which belongs to chemical adsorption.