Corrosion Resistance of Electrochemically Synthesized Modified Zaccagnaite LDH-Type Films on Steel Substrates

Modified zaccagnaite layered double hydroxide (LDH) type films were synthesized on steel substrates by pulsed electrochemical deposition from aqueous solutions. The resulting films were characterized by X-ray diffraction, scanning electron microscopy/X-ray dispersive spectroscopy, and Fourier transform infrared spectroscopy. Structural characterization indicated a pure layered double hydroxide phase; however, elemental analysis revealed that the surface of the films contained Zn:Al ratios outside the typical ranges of layered double hydroxides. Layer thickness for the deposited films ranged from approximately 0.4 to 3.0 μm. The corrosion resistance of the film was determined using potentiodynamic polarization experiments in 3.5 wt.% NaCl solution. The corrosion current density for the coatings was reduced by 82% and the corrosion potential was shifted 126 mV more positive when 5 layers of modified LDH coatings were deposited onto the steel substrates. A mechanism was proposed for the corroding reactions at the coating.

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Removal of Lead from Aqueous Solution by Adsorption using Magnesium Aluminium Hydrogenphosphate Layered Double Hydroxides

Malaysian Journal of Fundamental and Applied Sciences ◽

10.11113/mjfas.v8n1.117 ◽

2014 ◽

Vol 8 (1) ◽

Author(s):

Zaini Hamzah ◽

Mohd Najif Ab Rahman ◽

Yamin Yasin ◽

Siti Mariam Sumari ◽

Ahmad Saat

Keyword(s):

Aqueous Solution ◽

Layered Double Hydroxide ◽

Molar Ratio ◽

Maximum Adsorption Capacity ◽

Lead Removal ◽

X Ray Diffraction ◽

X Ray ◽

Co Precipitation ◽

Double Hydroxide ◽

Double Hydroxides

Layered double hydroxide with molar ratio of 4 (MAN 4) was synthesized by co-precipitation and followed by hydrothermal method. The compound was then later going through ion exchange with K2HPO4 for 48 hours to produce MgAlHPO4 (MAHP 4). The solid produced were characterized using X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). Adsorption of lead solution by MAHP 4 was carried out using batch experiment by mixing the lead solution and the solid of layered double hydroxide. The effects of various parameters such as contact time, pH, adsorbent dosage and initial concentration were investigated. The optimum pH for lead removal was found to be at pH of 5 and the optimum time of lead removal was found at 2 hours. The isotherm data was analysed using Langmuir and the correlation coefficient of 0.998 was obtained. The maximum adsorption capacity, Qo (mg/g) of 500 mg/g was also recorded from the Langmuir isotherm. The remaining lead solution was determined by using EDXRF (Energy Dispersive X-Ray Fluorescence spectrometry) model MiniPal 4 (PAN analytical). The results in this study indicate that MAHP 4 was an interesting adsorbent for removing lead from aqueous solution.

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Photocatalytic Degradation of 2,4,6-Trichlorophenol by MgO–MgFe2O4 Derived from Layered Double Hydroxide Structures

Catalysts ◽

10.3390/catal9050454 ◽

2019 ◽

Vol 9 (5) ◽

pp. 454 ◽

Cited By ~ 5

Author(s):

Esthela Ramos-Ramírez ◽

Francisco Tzompantzi-Morales ◽

Norma Gutiérrez-Ortega ◽

Héctor G. Mojica-Calvillo ◽

Julio Castillo-Rodríguez

Keyword(s):

Photocatalytic Degradation ◽

Layered Double Hydroxides ◽

X Ray Diffraction ◽

Application Study ◽

Toxic Compounds ◽

X Ray ◽

Thermally Activated ◽

Double Hydroxide ◽

Double Hydroxides ◽

Scanning Electron

In recent years, the search for solutions for the treatment of water pollution by toxic compounds such as phenols and chlorophenols has been increasing. Phenols and their derivatives are widely used in the manufacture of pesticides, insecticides, paper, and wood preservers, among other things. Chlorophenols are partially biodegradable but not directly photodegradable by sunlight and are extremely toxic—especially 2,4,6-trichlorophenol, which is considered to be potentially carcinogenic. As a viable proposal to be applied in the treatment of water contaminated with 2,4,6-trichlorophenol, this paper presents an application study of the thermally activated Mg/Fe layered double hydroxides as photocatalysts for the mineralization of this contaminant. Activated Mg/Fe layered double hydroxides were characterized by X-ray diffraction, thermal analysis, N2 physisorption, and scanning electron microscopy with X-ray dispersive energy. The results of the photocatalytic degradation of 2,4,6-trichlorophenol in aqueous solution showed good photocatalytic activity, with an efficiency of degradation of up to 93% and mineralization of 82%; degradation values which are higher than that of TiO2-P25, which only reached 18% degradation. The degradation capacity is attributed to the structure of the MgO–MgFe2O4 oxides derived from double laminate hydroxide Mg/Fe. A path of degradation based on a mechanism of superoxide and hollow radicals is proposed.

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A microstructural and corrosion resistance study of (Zr, Si, Ti)N-Ni coatings produced through co-sputtering

DYNA ◽

10.15446/dyna.v85n207.73304 ◽

2018 ◽

Vol 85 (207) ◽

pp. 192-197 ◽

Cited By ~ 1

Author(s):

Estrella Natali Borja-Goyeneche ◽

Jhon Jairo Olaya-Florez

Keyword(s):

Corrosion Resistance ◽

Nickel Content ◽

Corrosion Current ◽

Nacl Solution ◽

X Ray Diffraction ◽

X Ray ◽

X Ray Scattering ◽

Current Densities ◽

Fcc Phase

This work researches the influence of the nickel content on the structural and anticorrosive properties of ZrSiTiN films deposited by means of reactive co-sputtering on alloys of Ti6Al4V. The morphology and structure were analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the chemical composition was identified via X-ray scattering spectroscopy (EDS). The corrosion resistance was studied using potentiodynamic polarization (PP) tests employing a 3.5% by weight NaCl solution. In the films, an increase of Ni up to 6.97 at% was observed, while in XRD the FCC phase of (Zr, Ti) N was identified, with a mixed orientation in planes (111) and (200), which tended to diminish with the increase of Ni. Finally, with the addition of Ni, the corrosion current densities were reduced from 5.56 𝑥 10−8 to 2.64 𝑥 10−9 𝐴/𝑐m2. The improvement in the corrosion resistance is due to the effect of the Ni on the microstructure of the system (Zr, Ti) N, which can improve the quality of the passive film and prevent crystalline defects and corrosion zones.

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ETHANOL SENSOR OF CdO/Al2O3/CeO2 OBTAINED FROM Ce-DOPED LAYERED DOUBLE HYDROXIDES WITH HIGH RESPONSE AND SELECTIVITY

Functional Materials Letters ◽

10.1142/s1793604713500355 ◽

2013 ◽

Vol 06 (03) ◽

pp. 1350035 ◽

Cited By ~ 4

Author(s):

DONGMEI XU ◽

MEIYU GUAN ◽

QINGHONG XU ◽

YING GUO ◽

YAO WANG

Keyword(s):

Photoelectron Spectroscopy ◽

Gas Sensing ◽

X Ray Diffraction ◽

X Ray ◽

Composite Oxides ◽

Structure Morphology ◽

Ft Ir ◽

Ethanol Sensing ◽

Double Hydroxide ◽

Double Hydroxides

In this paper, Ce -doped CdAl layered double hydroxide (LDH) was first synthesized and the derivative CdO/Al2O3/CeO2 composite oxide was prepared by calcining Ce -doped CdAl LDH. The structure, morphology and chemical state of the Ce doped CdAl LDH and CdO/Al2O3/CeO2 were also investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), solid state nuclear magnetic resonance (SSNMR), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The gas sensing properties of CdO/Al2O3/CeO2 to ethanol were further studied and compared with CdO/Al2O3 prepared from CdAl LDH, CeO2 powder as well as the calcined Ce salt. It turns out that CdO/Al2O3/CeO2 sensor shows best performance in ethanol response. Besides, CdO/Al2O3/CeO2 possesses short response/recovery time (12/72 s) as well as remarkable selectivity in ethanol sensing, which means composite oxides prepared from LDH are very promising in gas sensing application.

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In Situ Polymerization and Characterization of Poly(ε-caprolactone)/Layered Double Hydroxide Nanocomposites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.557-559.371 ◽

2012 ◽

Vol 557-559 ◽

pp. 371-374

Author(s):

Lian Liu ◽

Teng Yu ◽

Pei Wang ◽

Guang Shuo Wang

Keyword(s):

Layered Double Hydroxide ◽

In Situ Polymerization ◽

X Ray Diffraction ◽

Visible Spectroscopy ◽

X Ray ◽

Uv Visible ◽

Absorbance Peak ◽

Double Hydroxide

Nanocomposites of poly(ε-caprolactone) (PCL) and layered double hydroxide (LDH) were prepared by in situ polymerization at low LDHs loadings in this work. The resultants were characterized by FTIR spectroscopy, X-ray diffraction (XRD), differential scanning calorimeter (DSC) and UV-visible spectroscopy (UV-vis). FTIR showed that the PCL/LDHs nanocomposites were prepared successfully by in situ polymerization and XRD spectra showed that the crystal structure did not change greatly in the presence of LDHS. DSC results confirmed that LDHs could act as nucleating agents. UV-vis spectra showed that LDHs had stronger absorbance peak than LDH. Moreover, the PCL/LDHs nanocomposites had strong anti-ultraviolet effect by introduction of LDHs into polymer matrix.

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Preparation of ZnAl2O4 Spinel Directly from Zinc Aluminum Layered Double Hydroxide Precursor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.567.127 ◽

2012 ◽

Vol 567 ◽

pp. 127-130

Author(s):

Jian Ye Song ◽

Ming Zhe Leng ◽

Xing Qi Fu ◽

Jian Qiang Liu

Keyword(s):

Layered Double Hydroxide ◽

Single Phase ◽

Structural Characteristics ◽

Atomic Level ◽

X Ray Diffraction ◽

Simple Route ◽

X Ray ◽

Znal2o4 Spinel ◽

Double Hydroxide ◽

Scanning Electron

Single-phase ZnAl2O4 spinel has been prepared by a novel simple route using layered double hydroxide as a precursor. ZnAl2O4 spinel is directly obtained by calcination of zinc aluminum layered double hydroxide (Zn/Al molar radio is 0.5) without further chemical treatment. The key feature of this method is that it affords uniform distribution of all metal cations on an atomic level in the precursor. The structural characteristics of the as-synthesized precursor and the resulted calcined products are obtained by X-ray diffraction and scanning electron microscope.

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Influences of Surface Nanocrystallization Induced by High-Energy Spot Peening on Microstructure and Properties of Magnesium Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.2120 ◽

2013 ◽

Vol 690-693 ◽

pp. 2120-2125 ◽

Cited By ~ 1

Author(s):

Li Wen Tang ◽

Jian Sun ◽

Jin Zhang ◽

Xin Bing Ou ◽

Zhi Ming Zhou

Keyword(s):

Surface Layer ◽

Magnesium Alloys ◽

Corrosion Potential ◽

Electrochemical Measurement ◽

Corrosion Current ◽

High Energy ◽

X Ray Diffraction ◽

X Ray ◽

Surface Nanocrystallization ◽

Grain Sizes

As relatively new structure materials, magnesium and its alloys demonstrated significant potential for applications in many industries. However, magnesium alloys were easy to be corroded which greatly limited their development. AZ31B and AZ91D, two widely used commercial magnesium alloys in various industries, were chosen to be produced nanostructure on the surface layer, called Surface Nanocrystallization (SNC) by High Energy Spot Peening (HESP). The microstructure was characterized by Scan Electronic Microscopy (SEM) and X-ray diffraction (XRD) in this paper. Microhardness and corrosion resistance were measured by microhardness tester and electrochemical measurement system respectively. Experimental results showed that after HESP the grain sizes in the surface layer were obviously reduced into nanoscale; microhardness was greatly increased in the treated surface, about two times as much as that of original and corrosion current density in polarization curve was evidently raised while corrosion potential changed little.

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Synthesis and Characterization of New Layered Double Hydroxide-Polyolefin Film Nanocomposites with Special Optical Properties

Materials ◽

10.3390/ma12213580 ◽

2019 ◽

Vol 12 (21) ◽

pp. 3580 ◽

Cited By ~ 1

Author(s):

Fuensanta Monzó ◽

Ana Caparrós ◽

Diego Pérez-Pérez ◽

Alejandro Arribas ◽

Ramón Pamies

Keyword(s):

Optical Properties ◽

Mechanical Performance ◽

X Ray Diffraction ◽

X Ray ◽

Whitening Agent ◽

Thermoplastic Matrix ◽

Double Hydroxide ◽

Double Hydroxides ◽

Film Nanocomposites

In this study, we have synthesized new double layered hydroxides to be incorporated to low density polyethylene thermoplastic matrix. These new composites present promising applications as materials to build greenhouses due to the enhancement of their optical properties. A characterization of the modified nanoclay has been performed by means of X-ray fluorescence (XRF), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). We have prepared a series of polyolefin-based films to evaluate the effect of the addition of a whitening agent (disodium 2,2′-((1,1′-biphenyl)-4,4′-diyldivinylene)bis(benzenesulfonate)), the modified hydrotalcite-like material and a commercial dispersant. The rheological and mechanical characterization of the films have proved that the inclusion of the modified-layered double hydroxides (LDHs) do not substantially affect the processing and mechanical performance of the material. On the other hand, optical properties of the nanocomposites are improved by reducing the transmission in the UVA region.

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Microstructural Evolutions and its Impact on the Corrosion Behaviour of Explosively Welded Al/Cu Bimetal

Metals ◽

10.3390/met10050634 ◽

2020 ◽

Vol 10 (5) ◽

pp. 634

Author(s):

Mohammad Reza Jandaghi ◽

Abdollah Saboori ◽

Gholamreza Khalaj ◽

Mohammadreza Khanzadeh Ghareh Shiran

Keyword(s):

Corrosion Resistance ◽

Corrosion Potential ◽

Electrochemical Impedance ◽

Corrosion Behaviour ◽

Welding Process ◽

X Ray Diffraction ◽

X Ray ◽

Aluminium Copper ◽

Melting Pool ◽

Intermetallic Layers

In this study, the microstructural evolutions and corrosion resistance of aluminium/copper joint fabricated through explosive welding process have been thoroughly investigated, while stand-off distance was variable. Microstructural analyses demonstrate that, regardless of grain refinement in the welding boundary, increasing the stand-off space is followed by a higher thickness of the localized melting pool. X-Ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) analyses recognized the binary intermetallic layers as a combination of Al2Cu and AlCu. Polarization and electrochemical impedance spectroscopy (EIS) corrosion tests revealed that a higher stand-off distance resulted in the increment of corrosion potential, current rate, and concentration gradient at the interface owing to the remarkable kinetic energy of the collision, which impaired corrosion resistance.

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Zn-Al Layered Double Hydroxide Thin Film Fabricated by the Sputtering Method and Aqueous Solution Treatment

Coatings ◽

10.3390/coatings10070669 ◽

2020 ◽

Vol 10 (7) ◽

pp. 669

Author(s):

Jaehwan Shin ◽

Kyunghwan Kim ◽

Jeongsoo Hong

Keyword(s):

Aqueous Solution ◽

Solution Treatment ◽

X Ray Diffraction ◽

Zno Film ◽

Experiment Data ◽

X Ray ◽

Facing Target Sputtering ◽

Double Hydroxide ◽

Double Hydroxides ◽

Synthesis Experiment

Zn-Al layered double hydroxides (LDHs) were synthesized herein via a simple process. First, Al-doped ZnO film was deposited onto a glass substrate using the facing target sputtering system. Successful synthesis of the Zn–Al LDH was achieved via a treatment process using an aqueous solution which contains NO3− anions. X-ray diffraction analysis confirmed that it was consistent with the previous Zn–Al LDH synthesis experiment data, and the calculated d-value was 9.1 Å. Scanning electron microscopy observations revealed that the as-synthesized sample had a plate-like structure.

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