scholarly journals Development and Performance Evaluation of Corrosion Resistance Self-Healing Coating

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Akshya Kumar Guin ◽  
Suryakanta Nayak ◽  
Manish Kumar Bhadu ◽  
Veena Singh ◽  
Tapan Kumar Rout

Polymer based nanocapsule was developed using core-cell approach, where the core material was methyl diphenyl diisocyanate and the cell material was urea-formaldehyde. The synthesized capsules of 100 to 800 nm size were incorporated into sol-gel matrix to prepare a final coating for steel protection. This coating was found protecting the steel at the damage or crack locations in 3.5% NaCl solution. SEM micrographs confirmed healing of the coating at the damage or crack points.

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaoxing Yan ◽  
Yijuan Chang ◽  
Xingyu Qian

Urea formaldehyde resin-coated epoxy resin microcapsules were prepared by two-step in situ polymerization. The effects of five factors on the yield, coverage rate, repair rate, and morphology of the microcapsules were investigated by five factors and four levels of orthogonal test. These five factors were the mass ratio of the core to the wall material (Wcore:Wwall), the mass ratio of the emulsifier to the core material (Wemulsifier:Wcore), stirring rate, deposition time, and mass ratio of the emulsifier solution to the core material (Wemulsifier solution:Wcore). The ideal technological level of microcapsule synthesis was determined. According to the results of the range and variance of yield, coverage rate, and repair rate, the comprehensive properties of microcapsules became ideal. At this time, the Wcore:Wwall was 0.8 : 1, Wemulsifier:Wcore was 1 : 100, stirring rate was 600 r/min, deposition time was 32 h, and Wemulsifier solution:Wcore was 8 : 1. When the concentration of microcapsules in the epoxy resin was 10.0%, the self-repair rate was the best and the repair rate was 114.77%. This study is expected to provide a reference value for the preparation of a microcapsule self-healing technology and lay a foundation for the subsequent development of self-healing materials.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2366 ◽  
Author(s):  
Xiaoxing Yan ◽  
Yu Tao ◽  
Xingyu Qian

Microcapsules were prepared by in situ polymerization with urea formaldehyde resin as the wall material and Dulux waterborne acrylic acid as the core material. The effects of the core–wall ratio, water bath temperature and depositing time on the morphology, particle size, yield and encapsulation ratio of microcapsules were investigated by orthogonal experiment of three factors and two levels. The results showed that the core–wall ratio had the greatest influence on the performance of microcapsules. When the core–wall ratio was 0.58:1, the water bath temperature was 70 °C, and the depositing time was 5 d, the microcapsule performance was the best. With the increase in depositing time, the yield of microcapsule particles increased gradually, and the microcapsules appeared to show an adhesive phenomenon. However, the long-term depositing time did not lead to complete deposition and agglomeration of microcapsules. When 10.0% concentration of the waterborne acrylic microcapsules with 0.58:1 of core–wall ratio was added to the coatings, the mechanical and optical properties of the coatings did not decrease significantly, but the elongation at break increased significantly. Therefore, this study offers a new prospect for using waterborne acrylic microcapsules to improve the toughness of waterborne paint film which can be cured at room temperature on a wood surface.


2014 ◽  
Vol 61 (6) ◽  
pp. 416-422 ◽  
Author(s):  
Mansoureh Parsa ◽  
Seyed Mohammad Ali Hosseini ◽  
Zahra Hassani ◽  
Effat Jamalizadeh

Purpose – The purpose of this paper was to study the corrosion resistance of water-based sol-gel coatings containing titania nanoparticles doped with organic inhibitors for corrosion protection of AA2024 alloy. Design/methodology/approach – The coatings were obtained using tetraethylorthosilicate, 3-glycidoxypropyltrimethoxysilane, titanium (IV) tetrapropoxide and poly(ethylene imine) polymer as cross-linking agents. As corrosions inhibitors, 2-mercaptobenzoxazole and salicylaldoxime were incorporated into the sol-gel for the improvement of the corrosion resistance. The corrosion protection performance of coatings was studied using the potentiodynamic scan and the electrochemical impedance spectroscopy (EIS) methods. Atomic force microscopy was used to investigate surface morphology of the coatings. Findings – The results indicated that doping the sol-gel coatings with inhibitors leads to improvement of the corrosion protection. The comparison of doped coatings confirmed that corrosion protection performance of the sol-gel coatings doped with 2-mercaptobenzoxazole was better than for the sol-gel coatings doped with salicylaldoxime. Also the EIS results verified self-healing effects for the sol-gel coatings doped with 2-mercaptobenzoxazole. Originality/value – This paper indicates 2-mercaptobenzoxazole and salicylaldoxime can be added as corrosion inhibitors to sol-gel coatings to improve their corrosion protective properties for AA2024 alloy.


RSC Advances ◽  
2015 ◽  
Vol 5 (1) ◽  
pp. 706-716 ◽  
Author(s):  
F. Ansari ◽  
R. Naderi ◽  
C. Dehghanian

An eco-friendly silane sol–gel coating incorporating nanoclay was formulated to provide an effective corrosion protection for stainless steel 304L in a NaCl solution.


Author(s):  
Yaser Atta Yassin ◽  
Ali Nasser Hussain ◽  
Nagham Yassin Ahmed

This paper presents a core losses and performance calculation with different type of steel materials in the core design for three-phase induction motor by using "ANSYS Maxwell" program in order to identify the core material that provides the most effective performance by iron losses reduction. The coefficients of core losses are calculated from the magnetization curve and core Loss curve based on the on steel material databases. Although the difficult to obtain because of the little of existing information. Results show the capability of the proposed Cobalt steel (Hiperco 50) to achieve the significant losses reduction in comparison to the Electrical Steel NGO–AK Steel’s M-19 and Low Carbon Steel-SAE1020.


Author(s):  
Emmanuel ACOSTA-PEREZ ◽  
Mercedes SALAZAR-HERNÁNDEZ ◽  
Juan Manuel MENDOZA-MIRANDA ◽  
Carmen SALAZAR-HERNÁNDEZ

Thermal barrier Coatings (TBC) are a system of layers covering a surface with the aim to increase its insulation as well as protect the core of oxidation. In this paper the use of silica ceramics modified by polydimethylsiloxane (PDMS) as a new TBC for steel surface is proposed. The ceramics were obtained according to sol-gel methodology forming a stable sol mixing tetraethoxyetilsilicate (TEOS) at different percentage of PDMS (10, 20, 40 and 100%); the gelling was done using DBTL (dibutildilaurate tin) as a polycondensation catalyst. Therefore, the sol was applied on AISI-1018 steel surface by inmersion and a densification process is applied. The ceramic was characterized by infrared spectroscopy to observe its silica structure changes produced by the thermal treatment. Finally, the analysis the densification effect on properties on thermal conductivity and corrosion resistance was carried on.


2019 ◽  
Vol 18 (3) ◽  
pp. 281-290
Author(s):  
Iwan Susanto ◽  
Nugroho Eko Setijogiarto ◽  
Tia Rahmiati ◽  
Fachruddin Fachruddin ◽  
Arifia Ekayuliana ◽  
...  

The core shell structure of TiO2@SiO2@ferrite(Ni-Cu-Zn) as composite nanoparticles for magnetic photocatalyst were successfully prepared in this study. These particles were synthesized continually by the sol-gel method and they are tested for their performance using MB dye solution. The magnetic core particles used in the synthesis were (Ni-Cu-Zn) ferrite with size of 20-60 nm, while SiO2 and TiO2 layers were formed using tetraethoxysilane and tetrabutly titanate. Some characterizations and testinghavecarried out to investigate the crystal structure, magnetic properties, surface conditions and performance of these particles. The results show that the anatase crystal structure of TiO2 was obtained on the outer shell of the particle, while the magnetization value and surface area were achieved at 4.74 emu/g and 126,831 m2/g, respectively. The nanoparticles of composite size were obtained about 10 to 40 nm with the shell thickness up to 4 nm. The performance results of photodegradation was quite good for reducing MB dye up to 63.37%.


2014 ◽  
Vol 73 (1) ◽  
pp. 127-132 ◽  
Author(s):  
I. B. Singh ◽  
Prasant Gupta ◽  
Arpit Maheshwari ◽  
Naveen Agrawal

2020 ◽  
Vol 12 (31) ◽  
pp. 3954-3963 ◽  
Author(s):  
Jiaxin Hu ◽  
Cheng Qian ◽  
Yinchenxi Zhang ◽  
Yonghui Tian ◽  
Yixiang Duan

Widespread use of organophosphorus pesticides poses serious environmental threats, and hence calls for effective analysis methods for these classes of compounds.


2015 ◽  
Vol 1120-1121 ◽  
pp. 750-762 ◽  
Author(s):  
Yu Mei Han ◽  
Masoud Farzaneh

In the present study, a thick, uniform and crack-free sol-gel coating embedded with Al2O3-CeO2 nanoparticles was successfully synthesized and deposited on aluminum alloy AA6061 by spin coating method. The coating morphology was characterized by using a scanning electron microscopy coupled with electron diffraction x-ray spectrometer (SEM-EDX), an atomic force microscopy (AFM) and water contact angle measurements. FT-IR spectra were obtained using a Fourier transformation infrared spectrometer. The corrosion resistance of this coating in 3.5 wt.% NaCl solution was evaluated with electrochemical methods including potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The stability of the corrosion resistance of this coating was evaluated by immersion in 3.5 wt.% NaCl solution and by exposure to the UV radiation condition. In addition, the adhesion resistance of the coating was also assessed. SEM and AFM results showed that Al2O3-CeO2 nanoparticles dispersed uniformly in the room temperature vulcanized (RTV) silicon rubber matrix and formed a thick and crack-free coating. Both polarization and impedance results reveal that CeO2-Al2O3 nanoparticles embedded silicon rubber coating can improve the corrosion resistance of the AA6061 alloy by more than three orders of magnitude. Meanwhile, the corrosion resistance of this coating was found to be stable under immersion in 3.5 wt.% NaCl solution and UV exposure conditions. However, excessive content of CeO2 nanoparticles in the coating made the coating morphology porous and decreased the thickness of the coating, which resulted in the decrease in the corrosion resistance of the coating.


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