We study the interaction of intrinsic electrochemical noise with autonomous nonlinear dynamics of a three-electrode electrochemical cell. The amplitude of this intrinsic (internal) noise, regulated by the concentration of chloride ions, is monotonically increased and the provoked dynamics is analyzed. The experimentally constructed coherence factor $\beta$ versus the concentration of the chloride ions’ curve has a unimodal shape indicating the emergence of intrinsic coherence resonance. The abscissa for the maxima of this unimodal curve corresponds to the optimum value of intrinsic noise where maximum regularity of the invoked dynamics is observed.

Graphite oxide is obtained by treating graphite with strong oxidizers. The bulk material disperses in basic solutions yielding graphene oxide. Starting from exfoliated graphite, different treatments were tested to obtain the best graphite oxide conditions, including calcination for two hours at 700°C and ultrasonic agitation in acidic, basic, or peroxide solutions. Bulk particles floating in the solution were filtered, rinsed, and dried. The graphene oxide obtained was characterized under SEM and FTIR techniques. On the other hand, nylon 6-6 has excellent mechanical resistance due to the mutual attraction of its long chains. To take advantage of the properties of both materials, they were combined as a hybrid material. Electrochemical cells were prepared using porous silica as supporting electrode of the electrospun nylon/graphene oxide films for electrochemical testing. Polarization curves were performed to determine the oxidation/reduction potentials under different acidic, alkaline, and peroxide solutions. The oxidation condition was obtained in KOH and the reduction in H₂SO₄solutions. Potentiostatic oxidation and reduction curves were applied to further oxidize carbon species and then reduced them, forming the nylon 6-6/functionalized graphene oxide composite coating. Electrochemical impedance measurements were performed to evaluate the coating electrochemical resistance and compared to the silica or nylon samples.

The quantity of different plastics generated after consumption is an impact factor affecting the environment, and the lack of recycling generates solid waste. The purpose of this work is to incorporate high-density recycled polyethylene fibers (HDPE) for possible use as concrete reinforcement. Physical and mechanical properties from recycled fibers were analyzed, such as density, absorption, and stress resistance, as well as workability, air content, porosity, concrete compression, and flexural strength properties. Samples were prepared with a low fiber content of 0.2% and 0.4%, as a substitution for sand weight, and lengths of 10 and 30 mm. To study corrosion phenomena, the specimens were exposed to a saline environment containing 3% sodium chloride for 365 days, and the electrochemical techniques including half-cell potential (HCP), electrochemical noise (EN), linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) were applied. The results showed a 4.8% increase in compressive strength with a low fiber percentage and short geometries, while flexural strength increased marginally by 2.3% with small quantities of HDPE fibers. All these factors contribute to greater material durability, less permeability, and crack control. A positive effect of fibers with short dimensions on the corrosion processes of a steel bar was observed, with the fibers acting as a physical barrier against the diffusion of chloride ions.

A gemini surfactant imidazoline type, namely N-(3-(2-fatty-4,5-dihydro-1H-imidazol-1-yl) propyl) fatty amide, has been obtained from the fatty acids contained in the mango seed and used as a CO₂ corrosion inhibitor for API X-120 pipeline steel. Employed techniques involved potentiodynamic polarization curves, linear polarization resistance, and electrochemical impedance spectroscopy. These tests were supported by detailed scanning electronic microscopy (SEM) and Raman spectroscopy studies. It was found that obtained gemini surfactant greatly decreases the steel corrosion rate by retarding both anodic and cathodic electrochemical reactions, with an efficiency that increases with an increase in its concentration. Gemini surfactant inhibits the corrosion of steel by the adsorption mechanism, and it is adsorbed on to the steel surface according to a Langmuir model in a chemical type of adsorption. SEM and Raman results shown the presence of the inhibitor on the steel surface.

The corrosion behavior of pure aluminum (Al) in 20 v/v% ethanol–gasoline blends has been studied using electrochemical techniques. Ethanol was obtained from different fruits including sugar cane, oranges, apples, or mangos, whereas other techniques included lineal polarization resistance, electrochemical noise, and electrochemical impedance spectroscopy for 90 days. Results have shown that corrosion rates for Al in all the blends were higher than that obtained in gasoline. In addition, the highest corrosion rate was obtained in the blend containing ethanol obtained from sugar cane. The corrosion process was under charge transfer control in all blends; however, for some exposure times, it was under the adsorption/desorption control of an intermediate compound. Al was susceptible to a localized, plotting type of corrosion in all blends, but they were bigger in size and in number in the blend containing ethanol obtained from sugar cane.