Preparation and properties of natural gallic acid based rust conversion emulsion

2016 ◽  
Vol 45 (3) ◽  
pp. 191-198 ◽  
Author(s):  
Yuanfeng Jia ◽  
Nana Ren ◽  
Huadong Yue ◽  
Jianru Deng ◽  
Yali Liu
Keyword(s):  
Raman Spectroscopy ◽  
Corrosion Resistance ◽  
Gallic Acid ◽  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Hydroxyl Groups ◽  
Content Type ◽  
X Ray ◽  
Electrochemical Tests ◽  
Emulsion Polymerisation

Purpose The paper developed a novel gallic acid-based rust conversion emulsion (RCE) that is applied in the treatment of rusted steels. The purpose of this paper is to investigate the methods for the synthesis of RCE and study the mechanism of rust conversion. Design/methodology/approach Conversion emulsion was prepared using styrene, acrylate and self-developed gallic acid (GA)-based rust converter (GRC) via seed emulsion polymerisation. The polymerisable GRC was synthesised by the ring-opening reaction of glycidyl methacrylate with natural GA. The effects of the GRC dosage and its feeding modes on the RCE synthesis were analysed. The corrosion resistance, surface morphology, composition and mechanism of rust conversion coatings were studied using electrochemical tests, scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), respectively. Findings The results showed that conversion coating on rusted steels treated with RCE, with various dosages of GRC (weight per cent), synthesised using seed emulsion polymerisation, exhibited the best adhesion and corrosion resistance. Raman spectroscopy revealed that RCE converted the original multiphase rust into stable crystalline phases of α-Fe2O3 and Fe3O4. According to XPS and energy dispersive X-ray analysis, the phenolic hydroxyl groups of RCE were proposed to chelate with Fe ions to form macromolecular ferrum compounds. Research limitations/implications The pre-rusted steels demonstrated a better corrosion resistance than rust-free steels after treatment with RCE. Practical implications The paper developed a novel GA-based RCE with high efficiency and environment-friendly method. Originality/value This work is expected to replace the conventional rust conversion paints and cause a significant impact on extending the service life of rusted steels.

The influence of Ni on the microstructure and corrosion resistance of high-strength low alloy steel in the Cl-containing environment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dan Wang ◽  
Qingdong Zhong ◽  
Jian Yang ◽  
Shujian Zhang
Keyword(s):  
Corrosion Resistance ◽  
Alloy Steel ◽  
Photoelectron Spectroscopy ◽  
Hsla Steel ◽  
Electrochemical Techniques ◽  
High Strength ◽  
Low Alloy Steel ◽  
Transfer Resistance ◽  
Content Type ◽  
X Ray

Purpose This paper aims to search the optimum content of Ni on the microstructure, phase and electrochemical behavior of high-strength low alloy (HSLA) steel in the 3.5 wt.% NaCl solution. Design/methodology/approach The microstructure and corrosion resistance of Ni-containing HSLA steel in the simulated marine environment was studied by optical microscopy, scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical techniques. Findings The sample containing 3.55 wt.% of nickel exhibited a finer grain size of 10 μm and a lower icorr of 2.169 µA cm−2. The XRD patterns showed that the Fe-Cr-Ni solid solution, FeC and Cr3C2 were observed in samples when Ni was added. Besides, the 3.55 wt.% of nickel addition enhanced the charge transfer resistance of the low alloy steel which suggested the sample possessed excellent inhibition of electrochemical reaction and corrosion resistance. The XPS spectrum suggested that nickel was beneficial to improve the corrosion resistance of steel by forming protective oxides, and the ratio of Fe2+/Fe3+ in protective oxides was increased. Practical implications Finding the comprehensive performance of HSLA steel which can be applied to unmanned surface vehicles in marine operations. Originality/value This study has a guiding significance for optimizing the composition of HSLA steel in a Cl- containing environment.

MICROSTRUCTURE AND ELECTROCHEMICAL PROPERTIES OF Ni–B/GO ULTRASONIC-ASSISTED COMPOSITE COATINGS

2019 ◽  
Vol 26 (10) ◽  
pp. 1950080
Author(s):  
JIBO JIANG ◽  
HAOTIAN CHEN ◽  
LIYING ZHU ◽  
YAOXIN SUN ◽  
WEI QIAN ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Ultrasonic Field ◽  
Protective Material ◽  
X Ray ◽  
Electrochemical Tests ◽  
Ultrasonic Assisted ◽  
Corrosive Environments

Graphene oxide (GO) sheet and ultrasonic field (UF) were successfully employed to produce Ni–B/GO and UF–Ni–B/GO composite coatings on Q235 mild steel by electroless plating. The composite coatings’ structure and surface morphology were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Results showed that GO was successfully co-deposited in the Ni–B alloy. Moreover, UF–Ni–B/GO composite coatings have smoother surface and thicker cross-section than others. The microhardness and corrosion resistance of the sample coatings were determined using Vickers hardness tests, Tafel electrochemical tests and electrochemical impedance measurements (EIS) in 3.5[Formula: see text]wt.% NaCl solution to receive the effect of GO and ultrasonic. The findings indicated that UF–Ni–B/GO exhibited optimum hardness (856[Formula: see text]HV) and enhanced corrosion resistance (6.38 [Formula: see text][Formula: see text] over the Ni–B and Ni–B/GO coatings. Due to these interesting properties of the coating, it could be used as a protective material in the automotive and aerospace industries for parts of machines that were manipulated in high temperature and corrosive environments.

Preparation and characterization of a cerium conversion film on magnesium alloy

2015 ◽  
Vol 62 (4) ◽  
pp. 253-258 ◽  
Author(s):  
Jie Sun ◽  
Gang Wang
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Photoelectron Spectroscopy ◽  
Corrosion Current ◽  
Treatment Temperature ◽  
Conversion Coating ◽  
Conversion Coatings ◽  
Content Type ◽  
X Ray ◽  
Passivation Film

Purpose – The purpose of this paper was to prepare the cerium-based conversion coating on AZ91D magnesium alloy, and its compositions, micro-morphology, corrosion resistance and the chemical valence state of the film elements were investigated. Design/methodology/approach – The methodology comprised preparation of coatings at different temperatures, which then were characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, an electrochemistry workstation and by means of X-ray photoelectron spectroscopy. Findings – The conversion coating had a micro-cracked morphology. The conversion coatings were composed of MgO (or Mg-OH), CeO2 and Ce2O3. The best corrosion resistance of the cerium passivation film appeared when the treatment temperature was about 35°C. Originality/value – The corrosion current densities of conversion coatings were lower by one to two orders of magnitude than the corrosion current density of the blank sample. The rare earth passivation coating prepared under the best condition could reduce the corrosion current to 3.548 × 10−6 A/cm2.

scholarly journals Superhydrophobic Film on Hot-Dip Galvanized Steel with Corrosion Resistance and Self-Cleaning Properties

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 687 ◽  
Author(s):  
Chongchong Li ◽  
Ruina Ma ◽  
An Du ◽  
Yongzhe Fan ◽  
Xue Zhao ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Copper Nitrate ◽  
Galvanized Steel ◽  
Electrochemical Technique ◽  
Etching Time ◽  
Galvanic Replacement ◽  
Water Contact ◽  
X Ray ◽  
Self Cleaning

Super-hydrophobic film with hierarchical micro/nano structures was prepared by galvanic replacement reaction process on the surface of galvanized steel. The effects of the etching time and copper nitrate concentration on the wetting property of the as-prepared surfaces were studied. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and electrochemical technique were employed to characterize the surface morphology, chemical composition, and corrosion resistance. The stability and self-cleaning property of the as-fabricated super-hydrophobic film were also evaluated. The super-hydrophobic film can be obtained within 3 min and possesses a water contact angle of 164.3° ± 2°. Potentiodynamic polarization measurements indicated that the super-hydrophobic film greatly improved the corrosion resistance of the galvanized steel in 3.5 wt % NaCl aqueous solution. The highest inhibition efficiency was estimated to be 96.6%. The obtained super-hydrophobic film showed good stability and self-cleaning property.

scholarly journals Increased Electrical Conductivity of Carbon Nanotube Fibers by Thermal and Voltage Annealing

2021 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Varun Shenoy Gangoli ◽  
Chris J. Barnett ◽  
James D. McGettrick ◽  
Alvin Orbaek White ◽  
Andrew R. Barron
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Raman Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Separate Analysis ◽  
Sweet Spot ◽  
Electrical Conductor ◽  
X Ray ◽  
Resonant Raman ◽  
Carbon Nanotube Fibers

We report the effect of annealing, both electrical and by applied voltage, on the electrical conductivity of fibers spun from carbon nanotubes (CNTs). Commercial CNT fibers were used as part of a larger goal to better understand the factors that go into making a better electrical conductor from CNT fibers. A study of thermal annealing in a vacuum up to 800 °C was performed on smaller fiber sections along with a separate analysis of voltage annealing up to 7 VDC; both exhibited a sweet spot in the process as determined by a combination of a two-point probe measurement with a nanoprobe, resonant Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Scaled-up tests were then performed in order to translate these results into bulk samples inside a tube furnace, with similar results that indicate the potential for an optimized method of achieving a better conductor sample made from CNT fibers. The results also help to determine the surface effects that need to be overcome in order to achieve this.

scholarly journals Fenton Degradation of Ofloxacin Using a Montmorillonite-Fe3O4 Composite

2020 ◽  
Vol 2 (1) ◽  
pp. 32
Author(s):  
Alamri Rahmah Dhahawi Ahmad ◽  
Saifullahi Shehu Imam ◽  
Wen Da Oh ◽  
Rohana Adnan
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Solar Irradiation ◽  
Precipitation Process ◽  
Wastewater Remediation ◽  
Solution Ph ◽  
X Ray ◽  
Subsequent Degradation ◽  
Co Precipitation

In this work, FeM composites consisting of montmorillonite and variable amounts of Fe3O4 were successfully synthesized via a facile co-precipitation process. They were characterized using X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), N2 adsorption-desorption, and Fourier transform infrared spectroscopy (FT-IR) techniques to explain the effect of Fe3O4 content on the physicochemical properties of the Fe3O4-montmorillonite (FeM) composites. The FeM composites were subsequently used as heterogeneous Fenton catalysts to activate green oxidant (H2O2) for the subsequent degradation of ofloxacin (OFL) antibiotic. The efficiency of the FeM composites was studied by varying various parameters of Fe3O4 loading on montmorillonite, catalyst dosage, initial solution pH, initial OFL concentration, different oxidants, H2O2 dosage, reaction temperature, inorganic salts, and solar irradiation. Under the conditions of 0.75 g/L FeM-10, 5 mL/L H2O2, and natural pH, almost 81% of 50 mg/L of OFL was removed within 120 min in the dark, while total organic carbon (TOC) reduction was about 56%. Moreover, the FeM-10 composite maintained high efficiency and was stable even after four continuous cycles, making it a promising candidate in real wastewater remediation.

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