Portugaliae
Electrochimica Acta

The long-standing history of low corrosion resistance in E316 CS poses a persistent challenge for its industrial applications. Green CI are among the most widely adopted and cost-effective methods to protect metals and alloys against corrosion. In this study, a novel approach involving controlled block polymerization of myrcene, a biobased isoprene dimer, with styrene, using a Nd(BH4)3(THF)3/BEM-based catalytic system, resulted in the synthesis of poly(1,4-trans myrcene-co-styrene) - PMy- copolymer. This transparent and adhesive copolymer was developed as CI agent. Experiments were conducted using WL method and electrochemical techniques, at various polymer Ct and IT. According to the results obtained from WL and electrochemical analyses, increased IE(%) was observed using a polymer Ct of V3, corresponding to 1,5 g/L, suggesting higher corrosion IE(%) properties. Electrochemical analyses revealed that PMy exhibited a uniform CI effect, with a cathodic predominance. Additionally, Rct of CS electrode in an untreated solution increased from 71.25 to 668.3 Ω cm-2, in a solution with PMy, after 24 h of IT. Keywords: CI; E316 CS; HCl solution; PMy.

into the effects of permanent magnetic field (MF) on water. The water molecule is polar, with a bond angle of approximately 104.5°. Electrical charges at O and H atoms were unevenly distributed. The negative charge was drawn toward O atom, and positive charges were redistributed toward H atoms. Water is a polar solvent. The applied MF influenced the orientation of dynamics of H bonds between water molecules, of which process depended on MF parameters. Fourier Transform Infrared (FT-IR) spectroscopy was applied to research potassium carbonate (K2CO3). One indicator of magnets’ properties is magnetic induction. It was shown that MF and strength were essential for this effect, which was on a limescale, in a reversed scheme of arranging magnets. In a non-reversed scheme, the effects manifested in water. The authors researched the effects of a permanent MF on water with and without dissolved K2CO3. The potential application was for animal husbandry. Keywords: animal husbandry; FT-IR; K2CO3; magnetic field; water.

Recent research on capacitive deionization (CDI) materials indicates that salt removal efficiency of their cells can be increased by modifying one carbon electrode, with an electrode operating through a redox mechanism. A potential candidate is δ-MnO2, due to its diverse crystalline phase structure, low price and environmental friendliness. This study synthesized the layered phase of δ-MnO2 via sol-gel route, targeting a high-performance electrode for hybrid CDI (HCDI) technology. Analyzes results on δ-MnO2 composition and porosity were verified through BET, Raman, SEM and X-RD measurements. Electrochemical properties confirmed pseudo-capacitance charge-storage of δ-MnO2 and high durability, with specific capacitance (Csp) of 143 F/g, at a rate of 1 A/g, remaining stable after 1000 cycles. Efficiency of salt removal by optimal performance active material, at 1.4 V, with a moderate salt adsorption capacity (SAC) of 22.5 mg/g, was investigated. Keywords: δ-MnO2; HCDI; pseudo-capacitance; SAC; water desalination.

The corrosion rate of an orthodontic wire (OW) made of thermo active alloy (TAA) immersed in artificial saliva (AS), in the absence and presence of copper barrel brandy (CBB), was herein examined by potentiodynamic polarization study, and it was observed to decrease. When TAA was immersed in AS, in the presence of CBB, linear polarization resistance value decreased from 208.94 x 103 to 37.97 x 103 Ohm/cm2, and corrosion current increased from 2.192 x 10-9 to 12.99 x 10-9A/cm2. It was therefore determined that individuals using OW composed of TAA should refrain from orally ingesting CBB. The change in corrosion potential was observed to be within 50 mV, suggesting that CBB acted as a mixed-type additive. This implies that it enhanced both anodic and cathodic processes of corrosion. The results of this research could be utilized in the field of dentistry. TAA’s surface morphology was investigated by scanning electron microscope. Keywords: artificial saliva; copper barrel brandy; corrosion rate; dentistry; potentiodynamic polarization; scanning electron microscope; thermo active alloy.

Corrosion of rebars is a major problem faced by structures, especially in marine environments. Reinforcing bars are subjected to pitting corrosion from chloride attacks. Furthermore, structures are also susceptible to acid rain and attack from sulphate species. To overcome such challenges, surface engineering can be an effective option. Recent studies have shown rising focus of engineers and scientist on preventing corrosion from rebars and reinforcing steels, by applying a layer of coating. Such coatings include enamel, epoxy, duplex enamel and epoxy, galvanization, electroless Ni and self-healing coatings. They effectively shield the rebars by providing either barrier or passive protection. Therefore, the present work aimed to summarize different coating variants used for corrosion prevention of rebars, and present recent trends. Further research directions to make the coatings more cost-effective were also reviewed. Keywords: concrete; corrosion resistance; electrochemical corrosion; reinforcing steel; surface coating.