scholarly journals Chemical, electrochemical and surface studies of new metal–organic frameworks (MOF) as corrosion inhibitors for carbon steel in sulfuric acid environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abd El-Aziz S. Fouda ◽  
Safaa Eldin H. Etaiw ◽  
Gannat S. Hassan

AbstractThe effects of [Co2 (SCN) 4(hmt)2(H2O)6. H2O] (SC1) and [Co (CN)6 (Me3Sn)3(H2O). (qox)] (SCP2) MOF as corrosion inhibitors on C-steel in 0.5 M sulfuric acid solutions are illustrated utilizing mass reduction (MR), electrochemical [potentiodynamic polarization (PP), and AC electrochemical impedance (EIS)]. The experiments revealed that as the dose of these compounds rose, the inhibition efficacy (IE percent) of C-steel corrosion improved, reaching 80.7–93.1% at dose 25 × 10−6 M for SC1 and SCP2, respectively. IE percent, on the other hand, dropped as the temperature range grew. SC1was adsorbed physically and chemically (mixed adsorption) but SCP2 was adsorbed physically on the surface of C-steel and conformed to the Langmuir adsorption isotherm equation. The PP studies revealed that these compounds act as mixed kind inhibitors. To establish the morphology of the inhibited C-steel surface, scanning electron microscopy (SEM), energy transmitted X-ray (EDX), and atomic force microscopy (AFM) studies were used. All tested experiments were in good agreement.

2021 ◽  
Author(s):  
Abd El-Aziz S. Fouda ◽  
Safaa Eldin H. Etaiw ◽  
Gannat S. Hassan

Abstract The effects of [Co2(SCN)4(hmt)2(H2O)6. H2O] (SC1) and [Co (CN)6(Me3Sn)3(H2O). (qox)] (SCP2) MOF as corrosion inhibitors on C-steel in 0.5 M sulfuric acid solutions are illustrated utilizing mass reduction (MR), electrochemical [potentiodynamic polarization (PP), and AC electrochemical impedance (EIS)]. The experiments revealed that as the dose of these compounds rose, the inhibition efficacy (IE percent) of C-steel corrosion improved, reaching 80.7- 93.1 percent at dose 25x10-6 M for SC1 and SCP2, respectively. IE percent, on the other hand, dropped as the temperature range grew. Both SC1 and SCP2 were adsorbed physically on the surface of C-steel and conformed to the Langmuir adsorption isotherm equation. The PP studies revealed that these compounds act as mixed kind inhibitors. To establish the morphology of the inhibited C-steel surface, scanning electron microscopy (SEM), energy transmitted X-ray (EDX), and atomic force microscopy (AFM) studies were used. All tested experiments were in good agreement.


2021 ◽  
Author(s):  
Petar Stanić ◽  
◽  
Nataša Vukićević ◽  
Vesna Cvetković ◽  
Miroslav Pavlović ◽  
...  

Four 2-thiohydantoin derivatives were synthesized and their corrosion inhibition properties on mild steel (MS) in 0.5M HCl solution was evaluated using usual gravimetric and electrochemical methods (weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS). Morphology of the metal surface was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The study has shown that these compounds provide good protection for mild steel against corrosion in the acidic medium.


2020 ◽  
Vol 59 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Yao Wang ◽  
Jianqing Feng ◽  
Lihua Jin ◽  
Chengshan Li

AbstractWe have grown Cu2O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu2O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu2O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu2O film is more effective on phtocatalytic reduction of GO than MOD-Cu2O film. Moreover, reduction effect of self-oxidation Cu2O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction.


2021 ◽  
Author(s):  
Fajar Inggit Pambudi ◽  
Michael William Anderson ◽  
Martin Attfield

Atomic force microscopy has been used to determine the surface crystal growth of two isostructural metal-organic frameworks, [Zn2(ndc)2(dabco)] (ndc = 1,4-naphthalene dicarboxylate, dabco = 4-diazabicyclo[2.2.2]octane) (1) and [Cu2(ndc)2(dabco)] (2) from...


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 722
Author(s):  
Ioanna Christodoulou ◽  
Tom Bourguignon ◽  
Xue Li ◽  
Gilles Patriarche ◽  
Christian Serre ◽  
...  

In recent years, Metal-Organic Frameworks (MOFs) have attracted a growing interest for biomedical applications. The design of MOFs should take into consideration the subtle balance between stability and biodegradability. However, only few studies have focused on the MOFs’ stability in physiological media and their degradation mechanism. Here, we investigate the degradation of mesoporous iron (III) carboxylate MOFs, which are among the most employed MOFs for drug delivery, by a set of complementary methods. In situ AFM allowed monitoring with nanoscale resolution the morphological, dimensional, and mechanical properties of a series of MOFs in phosphate buffer saline and in real time. Depending on the synthetic route, the external surface presented either well-defined crystalline planes or initial defects, which influenced the degradation mechanism of the particles. Moreover, MOF stability was investigated under different pH conditions, from acidic to neutral. Interestingly, despite pronounced erosion, especially at neutral pH, the dimensions of the crystals were unchanged. It was revealed that the external surfaces of MOF crystals rapidly respond to in situ changes of the composition of the media they are in contact with. These observations are of a crucial importance for the design of nanosized MOFs for drug delivery applications.


2020 ◽  
Author(s):  
Pavel Alekseevskiy ◽  
Andrei N. Yankin ◽  
Marina O. Barsukova ◽  
Valentin A. Milichko

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1455
Author(s):  
Sabrina Patricia Rosoiu ◽  
Aida Ghiulnare Pantazi ◽  
Aurora Petica ◽  
Anca Cojocaru ◽  
Stefania Costovici ◽  
...  

The present work describes, for the first time, the electrodeposition of NiSn alloy/reduced graphene oxide composite coatings (NiSn-rGO) obtained under pulse current electrodeposition conditions from deep eutectic solvents (choline chloride: ethylene glycol eutectic mixtures) containing well-dispersed GO nanosheets. The successful incorporation of the carbon-based material into the metallic matrix has been confirmed by Raman spectroscopy and cross-section scanning electron microscopy (SEM). A decrease in the crystallite size of the coating was evidenced when graphene oxide was added to the electrolyte. Additionally, the topography and the electrical properties of the materials were investigated by atomic force microscopy (AFM). The corrosion behavior in 0.5 M NaCl solution was analyzed through potentiodynamic polarization and electrochemical impedance spectroscopy methods for different immersion periods, up to 336 h, showing a slightly better corrosion performance as compared to pure NiSn alloy.


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