Preparation and Characterization of Graphene Oxide/Polyaniline/Carbonyl Iron Nanocomposites

Nano coatings for anti−corrosion and electromagnetic wave absorbing can simultaneously implement the functions of assimilating electromagnetic waves and reducing the corrosion of materials caused by corrosive environments, such as seawater. In this work, a composite material for both electromagnetic wave absorption and anti−corrosion was prepared by an in−situ chemical oxidation and surface coating method using carbonyl iron powder (CIP), graphene oxide (GO) and aniline (AN). The synthesized composite material was characterized by scanning electron microscopy (SEM), infrared spectroscopy (FT−IR) and XRD. The carbonyl iron powder−graphene oxide−polyaniline (CIP−GO−PANI) composite material was used as the functional filler, and the epoxy resin was the matrix body for preparing the anticorrosive wave−absorbing coating. The results show that CIP had strong wave−absorbing properties, and the anti−corrosion property was greatly enhanced after being coated by GO−PANI.

Effect of (NH4)2ZrF6, Voltage and Treating Time on Corrosion Resistance of Micro-Arc Oxidation Coatings Applied on ZK61M Magnesium Alloys

The effects of (NH4)2ZrF6 concentration, voltage and treating time on the corrosion resistance of ZK61M magnesium alloy micro-arc oxidation coatings were studied by orthogonal experiments. The SEM result shows that the surface roughness and porosity of MAO coatings increased with (NH4)2ZrF6 concentration, voltage and treating time as a whole, except the porosity decreased with treating time. EDS, XRD and XPS analysis show that (NH4)2ZrF6 was successfully incorporated into coatings by reactive incorporation, coatings are dominantly composed of ZrO2, MgO, MgF2 and amorphous phase Mg phosphate. Potentiodynamic polarization was used to evaluate the corrosion property of coatings. When the concentration of (NH4)2ZrF6 is 6 g/L, the voltage is 450 V, and the treating time is 15 min, the coating exhibits the best corrosion resistance which corrosion current density is four magnitudes lower than substrate attributed to the incorporation of ZrO2 and the deposition of MgF2 in the micropores.

Effects of Additives Containing Cyanopyridine on Electrodeposition of Bright Al Coatings from AlCl3-EMIC Ionic Liquids

The Al coatings were electrodeposited on the Cu substrate from AlCl3-EMIC ionic liquid (AlCl3:EMIC = 2:1 molar ratio) containing three cyanopyridine additives with different positions of the substituent group on the pyridine ring, which were 2-cyanopyridine, 3-cyanopyridine, and 4-cyanopyridine. The effects of cyanopyridine additives on the deposition potential, morphology, brightness, and corrosion properties of Al coatings were investigated. It was considered that the deposition potential of Al shifted to more negative overpotentials, the quality of Al coatings was promoted, and the corrosion property was improved by the cyanopyridine additives to a varying degree. Especially in the presence of 4-cyanopyridine, the flattest mirror bright Al coating was obtained, which had the smallest homogeneous nanocrystal grain size and strongest Al (200) crystallographic orientation. The average roughness Ra value was as low as 31 nm compared to that in the absence of cyanopyridine additives, which was 417 nm. Furthermore, the corrosion current density of the bright Al coating was three orders of magnitude lower than the rough Al coating, which resulted from the dense nanocrystal structure.

Hydrazinecarbothioamide Derivative as an Effective Inhibitor for Corrosion Control: Electrochemical, Surface and Theoretical Studies

Aluminium has played a significant role in the advancement of metal matrix composites (MMC) and has drawn the attention of researchers since Al composites find extensive application in aerospace, military and automobile industries. This paper describes the corrosion property of 6061 Al-15 vol%. SiC(p) composites in hydrochloric acid medium. This composite with high strength-to-weight ratio and other alluring properties undergoes corrosion in acid media and a study has been made in 0.5 M hydrochloric acid using (2Z)-2-(2-hydroxy-3methoxybenzylidene) hydrazinecarbothioamide (HCT) as an inhibitor. Results of the electrochemical studies and surface morphology are presented. With the increase in HCT concentration, inhibition efficiency increased. But efficiency decreased with an increase in temperature. The maximum efficiency was found to be 56.8% for the addition of 10 × 10–5 M HCT concentration at 303 K. The inhibitor was found to behave as a mixed inhibitor affecting both anodic metal dissolution reaction and cathodic hydrogen evolution to the same extent. The HCT molecules were found to physisorb over the Al-composite surface and adsorption followed Langmuir’s adsorption isotherm. Adsorption of HCT was confirmed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Computational studies using density functional theory (DFT) supported experimental findings. Density functional theory calculations gave a clear insight into the mechanistic aspects of corrosion inhibition. Graphic Abstract

Advanced Carbon Materials for Sustainable and Emerging Applications

Advanced carbon nanomaterials, which comprises fullerene, graphene, and carbon nanotubes (CNTs) are considered as backbone of engineering and scientific Innovation due to their versatile chemical, physical and electrical properties. Sustainable carbon materials are fabricated using different physical and chemical methods, respectively. Moreover, fabrication methods are used to achieve advanced carbon monoliths which are constituents with desirable properties. Keeping a view of desirable monoliths, diverse allotropes of advanced carbon nanomaterials are mostly employed in renewable energy resources, organic photovoltaic, and energy conservation technology, respectively. Carbon nanomaterials offer tremendous potential for enhancing biology and drug delivery because of biocompatibility. The proposed chapter grants a variety of fabrications methods for sustainable carbon materials as well as highlights the miscellaneous applications. Further, graphene, carbon nanotube (CNT) and fullerene are considered as fast and effective nanocarriers for delivering therapeutic molecules. As advanced carbon materials have controllable porous structure, high surface area, high conductivity, high temperature stability, excellent anti-corrosion property and compatibility in composite materials so they can be employed in energy storage as electrocatalysts, electro-conductive additives, intercalation hosts and ideal substrate for active materials. Meanwhile, the chapter sums up the required demands of advanced carbon materials for technological innovation and scientific applied research.