Increasing attention is given to waterborne coatings for corrosion protection due to the lower ecological impact on the environment. It has been found that by using waterborne coatings, the emission ...of harmful volatile organic compounds (VOCs) is reduced by more than 50 g/L. However, they require longer drying time, their anti-corrosion performance is not as good as solvent-borne coatings and they still have not been developed for all corrosion environments. Another way to reduce VOCs is by using infrared (IR) drying technology. With catalytic infrared radiation, it is possible to cure all surfaces at notably reduced costs compared to traditional systems and in total respect for the environment, thanks to significant energy savings and minimal CO
emissions. The aim of this paper was to evaluate corrosion protective properties of waterborne coatings which were dried with traditional and accelerated drying techniques, i.e., under atmospheric conditions and by using IR technology. Two different coating systems were applied, with and without Zn in the primer. To achieve this goal, the test samples were subjected to electrochemical, corrosion, and physical tests. It was shown that infrared technology does not affect the quality of the coating and it drastically reduces the intercoating interval. A coating system with zinc in the primer showed better overall protection properties after being subjected to impedance and salt spray testing, but generally, solvent-borne coatings still have higher durability than waterborne in extreme marine conditions according to recent research. Microstructure and porosity remained intact and the atomic force microscope confirmed that the flash-off was conducted correctly since there were no pinholes and blisters detected on the coating's surface. This study can serve as a foundation for further investigations of IC-dried waterborne coatings because there are not many at the moment.
This article is a contribution to the development of the smart, self‐healing solutions in the context of corrosion protection of metallic materials based on nanotechnology. Mesoporous silica ...nanoparticles were successfully synthesized and loaded with two different corrosion inhibitors, 1‐hydroxybenzotriazole and 8‐hydroxyquinoline. Loaded particles were embedded in different concentrations in waterborne epoxy coating, and as such applied to low carbon steel substrates. A continuous immersion test in 3.5% NaCl solution, humidity chamber exposure, and salt spray exposure were performed. Successful synthesis of silica nanoparticles has been demonstrated using scanning electron microscopy and energy‐dispersive X‐ray spectroscopy characterization techniques. Fourier transform infrared spectroscopy was used to confirm the loading of inhibitors, while the quantity of loaded inhibitors was determined by thermogravimetric method. Anticorrosive performance of intact composite coatings was determined using electrochemical impedance spectroscopy and open‐circuit potential measurements. Adhesive properties were determined using the pull‐off test (ISO 4624). Significant improvement in corrosion protection performance has been demonstrated for coatings containing inhibitor‐loaded nanoparticles.
The application of organic coatings is a common way of protecting metal substrates against corrosion. To dry the coating faster, catalytic infrared radiation (IR) can be applied. This paper aims to ...assess the differences in the physical, chemical, and corrosion properties of primer coatings dried with catalytic infrared radiation, compared to the same coatings dried under atmospheric conditions. Corrosion properties were characterized using humidity and a salt spray chamber, as well as electrochemical impedance spectroscopy (EIS), preceded by open circuit potential (OCP) measurement. Pencil hardness, cross-cut, and pull-off adhesion tests were used to compare the properties of examined primers before and after testing in the corrosion acceleration chambers. The microstructure and distribution of chemical composition were studied by scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDX) together with Fourier-transform infrared spectroscopy (FTIR). Phase transitions in the coating were determined by differential scanning calorimeter (DSC). Infrared-dried primers achieved a higher curing degree. Therefore, their mechanical and corrosion properties are superior when compared to the same coatings dried under atmospheric conditions.
In the present work, the effect of aluminum nanoparticles inside epoxy resin and epoxy paint for the purpose of extending the service life of drainage pipes. The nanocomposite samples were analyzed ...with scanning electronic microscopy (SEM) and energy dispersive x‐ray analysis (EDX) to evaluate the dispersion of nanoparticles. Performed quantitative tests including electrochemical techniques, such as the method of electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) to determine impedance resistance on macro and micro levels. The antibacterial resistance of the nanocomposite samples was tested in the presence of Pseudomonas aeruginosa and Bacillus subtilis. All nanocomposite samples show an improvement in the measurement of impedance resistances and an increase in antibacterial effect by about 60% compared to the sample without nanoparticles.
The main goal of the work is to develop an active nanocomposite coating system that will extend the life of drainage pipes. Aluminum nanoparticles (Al NPs) are used for this purpose. Nanocomposite coatings show good Al NP dispersion within epoxy resin and paint, and improvement in electrochemical measurements and in antibacterial effect compared to the control sample without nanoparticles.
Ships’ hulls are typically coated with coating systems which have both anticorrosive and antifouling purposes, and consist of a primer, a tie coat, and an antifouling coat. Within this study, the ...protective properties of two different anticorrosion–antifouling coating systems are evaluated in a humid and warm atmosphere, as well as in a simulated marine environment utilizing salt spray chamber testing and immersion tests with and without agitation. The tested coating systems differ in the type of antifouling coating, i.e., self-polishing antifouling based on copper, and a new fouling-release coating based on miscellaneous components. The corrosion performances of Stojanović coatings in natural seawater are examined using open circuit potential measurements, electrochemical impedance spectroscopy, and pull-off tests. The antifouling properties are reviewed by visual examination, measurements of coating roughness before and after exposure to the testing solution, and after immersion in a solution containing
Saccharomyces cerevisiae
by measuring the optical density. The obtained results show better corrosion and antifouling properties of the coating system with a self-polishing antifouling top coat compared to the coating system with the foul-release top coat. A thicker biofilm was noticed on the plates immersed in seawater with agitation compared to stationary conditions for both antifouling coatings.
This paper examines the causes of death in children and adolescents for a ten-year period (2003-2012) according to data from the autopsy records of the Institute of Forensic Medicine in Niš. The ...causes of death (natural or violent) were analyzed in relation to sex, age, season, and environment (rural and urban areas), socio-economic and living conditions, and the number of children in the family. The results obtained were statistically analyzed, plotted and discussed in relation to data from the literature available. Regarding the autopsy cases of children and adolescents (194), 106 (54.63%) were the cases of violent causes of death and 87 were the cases (44.84%) of natural causes of death, while in one case the cause of death could not be determined due to late-stage decomposition alterations of the corpse. The most common natural causes of death were asphyxia, immaturity of the fetus and acute pneumonia. Most common causes of violent death were contusion of the brain, destruction of the brain and brainstem, polytrauma, and bleeding.
•The interfacial polyaddition method was used for the synthesis of microcontainers.•Containers loaded with inhibitors were incorporated into the waterborne matrix.•Feedback active response to local ...corrosion was successfully demonstrated.•The properties of different environments are one of the key performance factors.•Effect of different inhibitors and container concentrations has been demonstrated.
In this study, the corrosion inhibitors Zinc oleate and 8-Hydroxyquinoline were successfully encapsulated using an interfacial polyaddition method. As such they were dispersed at different concentrations within the waterborne coating matrix. The resulting composite coatings were applied to the low carbon steel substrates. Successful synthesis and morphological characteristics of microcontainers loaded with inhibitors were confirmed using various characterization techniques. Scanning electron microscopy, dynamic light scattering, and thermogravimetric measurements are techniques used to define the surface, dimensional, and dispersive characteristics of containers, and the share of encapsulated inhibitors. The release study defined the discharge kinetics of the corrosion inhibitor from the microcontainers dispersed freely in an aqueous medium. Electrochemical impedance spectroscopy was used to determine the anticorrosive performance of the samples continuously exposed to various corrosive environments of salt and humidity chambers and NaCl solution. Special emphasis was placed on adhesion testing and visual observations during the exposure period. Significant improvements have been noted in terms of corrosion resistance, which, however, depend on the type of inhibitor used, the concentration of the containers embedded in the coating matrix and on the characteristics of the corrosive environment.
This study investigates the morphology, composition and corrosion resistance of hot dip galvanized (HDG) steel bolts in fresh water, 1% NaCl saltwater in the presence of protective compounds ...L-Tryptophan and three conventional corrosion inhibitors: Inhibitor 1-VCI (amine-carboxylates-based), Inhibitor 2 (based on carboxylate acid), and Inhibitor 3 (water-based, carboxylate acid). Quantitative tests performed include gravimetric analysis and electrochemical techniques, such as linear polarization, Tafel extrapolation, and Electrochemical Impedance Spectroscopy (EIS). Electrochemical measurements determined the polarization resistance Rp, corrosion rate vcorr, and corrosion potential Ecorr. Furthermore, Scanning Electron Microscopy (SEM) and ATR-FTIR spectrometry were used to evaluate and characterize the formed layers on the surface of hot-dip galvanized steel samples. The results reveal that upon corrosion new compounds are formed onto the exposed areas of the treated bolts such as zinc-carbonates, zinc-hydroxides, etc. The presence of these compounds on the surface of the HDG steel bolts hinders the corrosion process by reducing the rate of the anodic and cathodic reactions. The gravimetric test showed that L-tryptophan in distilled water has mass increase, resulting from the formation of white deposits on the sample surface. In fresh water and distilled water, the best corrosion resistance was achieved with Inhibitor 1-VCI, while L-tryptophan showed best results in 1% NaCl solution.
DNA degradation in biological material needs to be better understood. Bloodstains on washed clothing are disturbed by washing procedures, sometimes transferred to other fabrics, often with latent ...bloodstains and usually with significantly degraded DNA. The samples (cotton fabric with bloodstains) are divided into six main groups, depending on the washing method regarding water temperature (95, 60, and 30 °C) and the detergent use. After completing the washing process, samples were stored for a certain period (1 day to 6 months) and subsequently analyzed. Analyses were performed using standard protocols and commercial kits to measure the remaining DNA quantity (concentration) and DNA degradation index in the processed samples. Our results revealed that the high washing temperature (60 and 95 °C) and the application of detergent have a synergic action on DNA degradation, while at 30 °C this effect is absent. Furthermore, the effect of detergent on accelerated DNA degradation is observed about a month after the washing. This delayed effect of detergent has no explanation in current literature data. To obtain optimal results from the bloodstains, we recommended that the period from the crime event and attempted cleaning by a perpetrator to the laboratory analysis should be less than 1 month.
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