co.organiccrap.com/38826.php Improved synthesis of graphene oxide. Small ; Mesoporous silica nanoparticles for active corrosion protection. Silane based chromate replacements for corrosion control, paint adhesion, and rubber bonding. Surf Eng. Characterization of thin water-based silane pre-treatments on aluminium with the incorporation of nano-dispersed CeO2 particles. Surf Coat Technol. Electrochemical study of modified non-functional bis-silane layers on Al alloy T3. Effects of Ce containing sol-gel coatings reinforced with SiO2 nanoparticles on the protection of AA Corrosion protection of sol-gel coatings doped with an organic corrosion inhibitor: Chloranil.
Prog Org Coat. Electrochemical study of inhibitor containing organic—inorganic hybrid coatings on AA J Electrochem Soc. Corrosion-resistant zeolite coatings by in situ crystallization. Electrochem Solid-State Lett. Anti-corrosive properties of silane coatings deposited on anodized aluminium. Electrochim Acta. A new family of mesoporous molecular sieves prepared with liquid crystal templates.
J Am Chem Soc. Graphene-based composite materials. Reduction of graphene oxide via L-ascorbic acid. Chem Commun. High quality reduced graphene oxide through repairing with multi-layered graphene ball nanostructures. Sci Rep.
One pot synthesis of graphene by exfoliation of graphite in ODCB. Development of oxidation and corrosion resistance hydrophobic graphene oxide-polymer composite coating on copper. Surf Coat Tech.
Nano-graphene oxide for cellular imaging and drug delivery. Nano Res. Photoluminescence and band gap modulation in graphene oxide. Appl Phys Lett. Photoluminescence from chemically derived graphene oxide. Quasi-molecular fluorescence from graphene oxide. Synthesis and evaluation of seed-directed hierarchical ZSM-5 catalytic supports: inductive influence of various seeds and aluminosilicate gels on the physicochemical properties and catalytic dehydrogenative behavior.
Mater Chem Phys. Front Environ Sci Eng. El-Maksoud SAA. The effect of organic compounds on the electrochemical behaviour of steel in acidic media - a review. Comparison of percentage weight loss and corrosion rate trends in different metal coupons from two soil environments. Int J Biodeterior Biodegrad. Standard practice for preparing, cleaning, and evaluating corrosion test specimens. Pennsylvania: ASTM; Green inhibitors: anti corrosive propensity of Garcinia mangostana for aluminum Solid State Phenom. Abiola OK, James A. The effects of Aloe vera extract on corrosion and kinetics of corrosion process of zinc in HCl solution.
The effect of aqueous extracts of some leaves and fruit-peels on the corrosion of steel, Al, Zn and Cu in acids. Brit Corros J. Al-Mhyawi SR. Corrosion inhibition of aluminum in 0. Orient J Chem. Weight loss measurement and theoretical study of new pyridazine compound as corrosion inhibitor for C38 steel in hydrochloric acid solution. Der Pharma Chemica. Port Electrochim Acta. Effect of Al additions and heat treatment on corrosion properties of Mg-Al based alloys.
J Achiev Mater Manuf Eng. Corrosion resistance through the application of anti-corrosion coatings.
In: M. Aliofkhazraei, editor. Developments in Corrosion Protection. InTechOpen; Corrosion inhibitors—principles, mechanisms and applications. Adhikari S, Hebert KR, Factors controlling the time evolution of the corrosion potential of aluminum in alkaline solutions. Lee D, Seo J. Three-dimensionally networked graphene hydroxide with giant pores and its application in supercapacitors. Papavinasam S. Corrosion Inhibitors. In: Revie RW, editor. Uhlig's Corrosion Handbook.
While an air spray system has been used on the materials shown here, they can also be incorporated into brush, roller or powder coatings that are solvent based, water based, low VOC or high solids. The inclusion of the CRCI into the coating had no effect on the adhesion of the coating to the substrate.
Testing of the material with crosshatch scribe according to ASTM D gave no indication of any reduction in adhesion to the substrate surface due the presence of the matrix-encapsulated materials. The gloss of the coatings for the CRCI material was measured and compared against the coating without the CRCI as well as a coating containing the traditional inhibitor for steel, zinc phosphate ZnPO 4.
The difference between the two materials and the minimal impact of the CRCI material in the coating is apparent on visual inspection. Gloss measurements of the coats were performed, with the results shown in Figure 3. The control coating and the CRCI-containing coating are very similar. They are within the margin of error of the measurements across the film.
The ZnPO 4 coating has a significantly low gloss value and could be classed as a matte finish. While the materials are capable of being used as a corrosion-control agent in a primer substituting for ZnPO 4 , the advantage of the matrix-controlled release material is the potential for incorporation into a direct-to-metal DTM topcoat.
This would add corrosion inhibition functionality to the topcoat. It would potentially reduce the need for two coats in a system by removing the primer and maintaining the gloss. Through careful manipulation of the chemistry of the pigment and the size of the pores in the particle, a tailored release profile can be achieved. Figure 4 shows the difference in release rates of an active based on the pore size of the particle matrix.
This allows the active to be released quickly at the site of corrosion to stop it in its tracks, or released slowly to extend the life of the coating by giving corrosion prevention over a longer lifetime.
The active in the matrix is released into the scribe during testing by diffusion from the matrix and it preserves the shininess of the scribe as is seen with traditional chromate inhibitors. This shininess was preserved for just under hrs in NSST. The coatings themselves demonstrated similar performance to other nonchromate inhibitors shown to have an inhibitory effect on corrosion out to hrs.
No blisters or corrosion products are seen in the scribe. The shiny scribe can be seen in comparison with the controls in Figure 5. For steel, the controlled release of the actives can be seen in comparison with the traditional inhibitor. The reduction in material allows for formulation with organic inhibitors at levels low enough to remove hazard labelling. The scraped steel plates can be seen in Figure 6. Using a profilometer the depth of the scribe for the steel plates was measured after scrapping, once hrs in NSST was completed.
The scribe depth measurement was used as a method of comparison between the traditional corrosion inhibitor ZnPO 4 and the CRCI material. The results can be seen in Figure 7 and it is obvious the CRCI material has significantly slowed or stopped the corrosion process in the scribe while both the control and the ZnPO 4 sample have undergone significant corrosion in the scribe, as seen with an overall increase in scribe depth when compared to the CRCI sample.
The plots in Figure 8 show the self-healing effect demonstrated by the controlled release of the active from the matrix. The coatings without the CRCI show significant corrosion in the scribe over time - with more corrosion seen at hrs immersion compared to the sample at 24 hrs. However, in the system with the CRCI, the admittance in the scratch is hardly seen at 24 hrs and only slightly more visible at hrs.
The admittance values for the CRCI sample are much lower than without by comparison. In addition to this, no corrosion was observed in the scribe of the sample with the matrix-encapsulated material. This result demonstrates the controlled release of the corrosion-inhibiting active from the matrix.
Once in the scratch, the corrosion process is halted or significantly retarded. It is possible to remove traditional inhibitors and incorporate smart pigment materials to give the same, if not a better, level of corrosion control in coatings. Moreover, these can also remove environmental, health and safety concerns due to heavy metals. Inhibispheres are shown to be a versatile and robust replacement for traditional corrosion inhibitors. They can be easily incorporated into water, solvent or powder coatings.
They can be tailored to whatever conditions are required with control over particle size and active release rate.
They have no significant impact on the final coating properties optical and mechanical. The controlled release mechanism allows for the extension of coating life and the inhibition of corrosion directly in the scribe. While the current application of this technology is in the area of corrosion inhibition for coatings, the matrix encapsulation technology can be applied to controlled release in antifouling, fire retardants, UV absorbers, etc.