scholarly journals Corrosion Resistance Evaluation of Self-Healing Epoxy Coating Based on Dual-Component Capsules Containing Resin and Curing Agent

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Alireza Safdari ◽  
Saied Nouri Khorasani ◽  
Rasoul Esmaeely Neisiany ◽  
Mohammad Sadegh Koochaki
Keyword(s):  
Electrochemical Impedance ◽  
Weight Ratio ◽  
Physical And Mechanical Properties ◽  
Epoxy Coating ◽  
Curing Agent ◽  
Self Healing ◽  
Healing System ◽  
Healing Efficiency ◽  
Ft Ir ◽  
Coating Matrix

In this study, a self-healing epoxy coating was prepared by incorporating a dual capsule healing system including epoxy resin and its amine-based curing agent. The emulsion electrospray technique was used for encapsulating the healing agents in poly(styrene co-acrylonitrile) (SAN) as shell material. Characterizing the prepared microcapsules (MCs) by Scanning Electron Microscopy (SEM) revealed their spherical morphology with the particle size of 827 nm and 749 nm for epoxy and amine cores, respectively. Fourier Transform Infrared Spectroscopy (FT-IR) and thermogravimetric analysis (TGA) results confirmed successful encapsulation with no side chemical reaction between the encapsulated core and shell materials. The effects of embedding MCs on the physical and mechanical properties of the epoxy coating matrix were studied by pull-off adhesion, conical mandrel bending, and gloss tests. In addition, the prepared coatings’ self-healing performance was evaluated by Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization (Tafel) experiments. The results revealed that the coating sample containing 1 wt% of core-shell MCs (a mixture of epoxy and amine-containing MCs with a 50 : 50 weight ratio) showed the best corrosion performance with 99% self-healing efficiency.

scholarly journals Preparation and Properties of Self-Healing and Self-Lubricating Epoxy Coatings with Polyurethane Microcapsules Containing Bifunctional Linseed Oil

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1578 ◽  
Author(s):  
Haijuan Yang ◽  
Qiufeng Mo ◽  
Weizhou Li ◽  
Fengmei Gu
Keyword(s):  
Interfacial Polymerization ◽  
Electrochemical Impedance ◽  
Linseed Oil ◽  
Salt Spray ◽  
Average Diameter ◽  
Organic Coating ◽  
Epoxy Coating ◽  
The Self ◽  
Self Healing ◽  
Pure Epoxy

An organic coating is commonly used to protect metal from corrosion, but it is prone to failure due to microcracks generated by internal stress and external mechanical action. The self-healing and self-lubricating achieved in the coating is novel, which allows an extension of life by providing resistance to damage and repair after damage. In this study, a new approach to microencapsulating bifunctional linseed oil with polyurethane shell by interfacial polymerization. Moreover, the self-healing and self-lubricating coatings with different concentrations of microcapsules were developed. The well-dispersed microcapsules showed a regular spherical morphology with an average diameter of ~64.9 μm and a core content of 74.0 wt.%. The results of the salt spray test demonstrated that coatings containing microcapsules still possess anticorrosion, which is improved with the increase of microcapsules content, after being scratched. The results of electrochemical impedance spectroscopy showed a |Z|f=0.01Hz value of 104 Ω·cm2 for pure epoxy coating after being immersed for 3 days, whereas the coating with 20 wt.% microcapsules was the highest, 1010 Ω·cm2. The results of friction wear showed that the tribological performance of the coating was enhanced greatly as microcapsule concentration reached 10 wt.% or more, which showed a 86.8% or more reduction in the friction coefficient compared to the pure epoxy coating. These results indicated that the coatings containing microcapsules exhibited excellent self-healing and self-lubricating properties, which are positively correlated with microcapsules content.

scholarly journals Cerium Dioxide Nanoparticles as Smart Carriers for Self-Healing Coatings

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 791 ◽  
Author(s):  
Sehrish Habib ◽  
Eman Fayyad ◽  
Muddasir Nawaz ◽  
Adnan Khan ◽  
Rana A. Shakoor ◽  
...  
Keyword(s):  
Corrosion Inhibition ◽  
Cerium Dioxide ◽  
Electrochemical Impedance ◽  
Protective Layer ◽  
Vital Role ◽  
Epoxy Coating ◽  
Gravimetric Analysis ◽  
Protective Film ◽  
Self Healing ◽  
Vis Spectroscopy

The utilization of self-healing cerium dioxide nanoparticles (CeO2), modified with organic corrosion inhibitors (dodecylamine (DDA) and n-methylthiourea (NMTU)), in epoxy coating is an efficient strategy for enhancing the protection of the epoxy coating and increasing its lifetime. Fourier transform infrared (FTIR) spectroscopy analysis was used to confirm the loading and presence of inhibitors in the nanoparticles. Thermal gravimetric analysis (TGA) measurement studies revealed the amount of 25% and 29.75% w/w for NMTU and DDA in the nanoparticles, respectively. The pH sensitive and self-release behavior of modified CeO2 nanoparticles is confirmed through UV-vis spectroscopy and Zeta potential. It was observed, through scanning electron microscopy (SEM), that a protective layer had been formed on the defect site separating the steel surface from the external environment and healed the artificially created scratch. This protective film played a vital role in the corrosion inhibition of steel by preventing the aggressiveness of Cl− in the solution. Electrochemical impedance spectroscopy (EIS) measurements exhibited the exceptional corrosion inhibition efficiency, reaching 99.8% and 95.7% for the modified coating with DDA and NMTU, respectively, after five days of immersion time.

scholarly journals Influence of SiO2 Content and Exposure Periods on the Anticorrosion Behavior of Epoxy Nanocomposite Coatings

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 118 ◽  
Author(s):  
Alam ◽  
Samad ◽  
Sherif ◽  
Poulose ◽  
Mohammed ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
High Performance ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Sio2 Nanoparticles ◽  
Epoxy Coating ◽  
Properties Of Coatings ◽  
Ft Ir ◽  
Eis Measurements ◽  
Coating Formulations

Epoxy coating formulations containing 1%, 3%, and 5% SiO2 nanoparticles were produced and applied on a mild steel substrate to achieve the objective of high performance corrosion resistance. The electrochemical impedance spectroscopy (EIS) technique was employed to measure the anticorrosive properties of coatings. The corrosion tests were performed by exposing the coated samples in a solution of 3.5% NaCl for different periods of time, varied from 1 h and up to 30 days. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses revealed the presence of nanoparticles in the final cured samples. Establishing the incorporation of the nanoparticles in the coating formulations was confirmed by employing both of XRD and FT-IR techniques. The FT-IR spectra have proved to be satisfactory indicating that there was a complete reaction between the epoxy resin with the hardener. EIS measurements confirmed that the presence and the increase of SiO2 nanoparticles greatly improved the corrosion resistance of the epoxy coating. The highest corrosion resistance for the coatings was obtained for the formulation with 5% SiO2 nanoparticles content, particularly with prolonging the immersion time to 30 days.

scholarly journals Green synthesis of nanocapsules for self-healing anticorrosion coating using ultrasound-assisted approach

2018 ◽  
Vol 7 (2) ◽  
pp. 147-159 ◽  
Author(s):  
Uday D. Bagale ◽  
Shirish H. Sonawane ◽  
Bharat A. Bhanvase ◽  
Ravindra D. Kulkarni ◽  
Parag R. Gogate
Keyword(s):  
Corrosion Inhibition ◽  
Electrochemical Impedance ◽  
In Situ Polymerization ◽  
Urea Formaldehyde ◽  
Immersion Test ◽  
Epoxy Coating ◽  
Self Healing ◽  
Actual Performance ◽  
Ultrasound Assisted

Abstract The present work deals with the production of nanocapsules containing a natural corrosion inhibition component. Azadirachta indica was encapsulated in urea-formaldehyde polymeric shell using ultrasound-assisted and conventional approaches of in situ polymerization. Subsequently nanocapsules were incorporated into clear epoxy polyamide to develop the green self-healing corrosion inhibition coating. The actual performance of the coating was evaluated based on the studies involving the repair of the crack of high solid surface coating. Corrosion inhibition of the healed area has been evaluated using the electrochemical impedance spectroscopy and immersion test based on the use of standard epoxy coating. The obtained results confirmed better corrosion protection in terms of the electrochemical impendence spectroscopy data and Tafel plot. It was found that current density decreases from 0.0011 A/cm2 (for standard epoxy coating) to 5.22 E−7 A/cm2 as 4 wt% nanocapsules incorporated in coating.

scholarly journals Magnetic Biopolymeric Hydrogel Composite Material with Self-healing Attribute

2021 ◽  
Vol 11 (6) ◽  
pp. 14881-14888
Keyword(s):  
Schiff Base ◽  
Magnetic Nanoparticles ◽  
Xanthan Gum ◽  
Silica Surface ◽  
Weight Ratio ◽  
Self Healing ◽  
Ft Ir ◽  
Modified Magnetic Nanoparticles ◽  
Surface Modified ◽  
Ft Ir Spectroscopy

This work presents a polysaccharide-based magnetic self-healing hydrogel fabricated through the incorporation of surface modified magnetic nanoparticles, a silica-surface modified magnetic - Fe3O4@SiO2, (MNP), to a polymer composite synthesized from the oxidation of xanthan gum (XG) and it's crosslinking with chitosan (CS) to generate Schiff base linkages rendering self-healing character. Fourier transform infrared (FT-IR) spectroscopy analyses revealed the successful formation of Schiff base bonding in the CS-OXG and CS-OXG-MNP hydrogels. In incorporating surface-modified magnetic nanoparticles, the resulting CS-OXG-MNP hydrogel with a weight ratio of 1:1:0.2, respectively, exhibited a better self-healing hydrogel in terms of faster self-healing characteristics and stronger mechanical property.

Boronic Ester-Polyurethane as a Self-Healing Coating Material for Offshore Top Side Structures Application

2021 ◽  
Author(s):  
Mohd Shamsul Farid Samsudin ◽  
Norfarah Diana Aba ◽  
Muzdalifah Zakaria ◽  
Azmi Mohammed Nor ◽  
Russell Varley ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Coating Layer ◽  
Salt Spray ◽  
The Self ◽  
Self Healing ◽  
Humidity Level ◽  
Healing System ◽  
Healing Efficiency ◽  
Harsh Conditions

Abstract Polymer coatings, especially epoxy and polyurethane paint systems, have been widely used to prevent corrosion of metallic components and structures. However, due to environmental and mechanical effects, the barrier efficiency of the coatings may be substantially compromised during transportation and service, as demonstrated by localized scratches, delamination, or stress-related microcracks. Application of a self-healing coating that can restore damages and recover its performance with minimal external intervention could prevent corrosion at the damaged coating. In this present work, the healing efficiency and long-term durability of Boronic Ester (BE) blended with Polyurethane (PU) as a self-healing system for top side coating of offshore platform structures was investigated. The BE was mixed at a ratio of 50:50 with PU resin and applied as a top layer on a PU coated steel plate with a thickness of approximately 300-350 μm. The healing efficiency, mechanical performance, and durability under simulated environmental conditions such as salt spray and UV were investigated according to the related ASTM standards. As a first step, the electrical impedance spectroscopy (EIS) and 3D profilemeter microscope were used to assess the healing ability of the scratched coating at room temperature and humidity level of 85 %. The mechanical performance of the self-healing coating layer was evaluated using a pull off adhesion test to investigate the compatibility of the self-healing system with the existing commercial PU topcoat system, while a long term 3000 hours salt spray and 4200 hours cyclic UV test were performed to evaluate the self-healing coating's durability in harsh conditions. Preliminary assessment using EIS and 3D profilemeter microscopes on the scratched PU/BE self-healing coating revealed significant healing efficiency of more than 80% for healing condition at ambient temperature and humidity level of 85%. The self-healing coating layer also demonstrated excellent adhesion efficiency, with adhesion greater than 300 psi suggesting good compatibility of the BE-PU layer with commercial PU coating. The salt spray and cyclic UV tests that were performed to determine the durability of the self-healing coating revealed that the 50BE/50PU layer remained intact and exhibited good healing performance with more than 80% efficiency even after exposure to harsh conditions. The findings from the study demonstrated that the BE/PU material has the potential to be used as a self-healing system for topside coating of offshore platforms structures, thereby lowering maintenance costs.

Microscopic Tests on Evaluation of Self-Healing Efficiency in Cementitious Materials with a Novel Self-Healing System

2020 ◽  
Vol 996 ◽  
pp. 104-109 ◽  
Author(s):  
Zhen Hong Yang ◽  
Xian Feng Wang ◽  
Ning Xu Han ◽  
Feng Xing
Keyword(s):  
Joint Action ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Self Healing ◽  
Test Results ◽  
Expansive Agent ◽  
Healing System ◽  
Healing Efficiency ◽  
Healing Agent

In this study, Na2CO3 solution as a self-healing agent was impregnated in LWA for autonomic self-healing on cracked cementitious material. The results showed that under the joint action of expansive agent, crystalline additive, phosphate and carbonate, the crack area showed a high self-healing efficiency (close to 70%) after curing in the still water 28d. SEM-EDS test results showed that in addition to ettringite and C-S-H/C-A-S-H, there was also a large amount of CaCO3 crystal in the depths of the crack.

Effects of dual component microcapsules of resin and curing agent on the self-healing efficiency of epoxy

2013 ◽  
Vol 55 ◽  
pp. 79-85 ◽  
Author(s):  
Qi Li ◽  
Siddaramaiah ◽  
Nam Hoon Kim ◽  
David Hui ◽  
Joong Hee Lee
Keyword(s):  
The Self ◽  
Curing Agent ◽  
Self Healing ◽  
Healing Efficiency

scholarly journals Pressurized vascular systems for self-healing materials

2011 ◽  
Vol 9 (70) ◽  
pp. 1020-1028 ◽  
Author(s):  
A. R. Hamilton ◽  
N. R. Sottos ◽  
S. R. White
Keyword(s):  
Fracture Toughness ◽  
Vascular System ◽  
Damage Zone ◽  
Capillary Forces ◽  
Self Healing ◽  
Vascular Networks ◽  
Healing System ◽  
Healing Efficiency ◽  
Healing Agent ◽  
Reactive Fluids

An emerging strategy for creating self-healing materials relies on embedded vascular networks of microchannels to transport reactive fluids to regions of damage. Here we investigate the use of active pumping for the pressurized delivery of a two-part healing system, allowing a small vascular system to deliver large volumes of healing agent. Different pumping strategies are explored to improve the mixing and subsequent polymerization of healing agents in the damage zone. Significant improvements in the number of healing cycles and in the overall healing efficiency are achieved compared with prior passive schemes that use only capillary forces for the delivery of healing agents. At the same time, the volume of the vascular system required to achieve this superior healing performance is significantly reduced. In the best case, nearly full recovery of fracture toughness is attained throughout 15 cycles of damage and healing, with a vascular network constituting just 0.1 vol% of the specimen.

Study on Corrosion Resistant Properties of Nano-SiO2 Modified Epoxy Coating

2012 ◽  
Vol 557-559 ◽  
pp. 1865-1868
Author(s):  
Xiao Hong Wang ◽  
Wei Gao ◽  
Beng Sheng Huang ◽  
Mei Yang ◽  
Yi Jun Shi
Keyword(s):  
Functional Group ◽  
Electrochemical Impedance ◽  
Epoxy Coating ◽  
Epoxy Coatings ◽  
Characteristic Functional ◽  
Corrosion Resistant ◽  
Scanning Electron Microcopy ◽  
Ft Ir ◽  
Fourier Transform Spectra ◽  
Modified Epoxy

Nano-SiO2 which surface was modified by silane coupling agent was used to modify the epoxy coatings which was prepared by the method of chemical modification and physical dispersion using the modified nano-SiO2 and epoxy. The molecular structure and dispersity of the modified nano-SiO2 were studied by Fourier transform spectra(FT-IR) and scanning electron microcopy(SEM). The effect of nano-SiO2 on corrosion resistance of epoxy coating was studied by electrochemical impedance spectroscopy(EIS). The results show that the modified nano-SiO2 contained the Si-OH characteristic functional group which can promoted the nano-SiO2 grafted with epoxy and had a good dispersion; Compared to epoxy coatings, wear rate of the modified epoxy coating reduced about 20% and the impedance value of the modified epoxy coating using the method of soak in 3.5% solution of NaCl for 240h, improved by 5 orders of magnitude.

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