Biochemical Characterisation of the Leaf of Morinda Lucida: Prospects for Environmentally-Friendly Steel-Rebar Corrosion-Protection in Aggressive Medium

Effects of Phyllanthus muellerianus Leaf-Extract on Steel-Reinforcement Corrosion in 3.5% NaCl-Immersed Concrete

“…In this study, however, P. muellerianus leaf-extract concentrations exhibited high effectiveness performance, which compares well to that obtained from positive (distilled water immersed) control samples, on the inhibition of steel-reinforcement corrosion in concrete for the saline/marine simulating environment. This performance was in similar manner with that by the P. muellerianus for the industrial/microbial environment in [36], and with that obtained by the also N-, S-, and O-containing Morinda lucida for the saline/marine environment in [72]. The corrosion inhibition effects by these natural plant-extracts find agreements with what obtained in reported works [73][74][75][76], where effective corrosion inhibition of steel material in acidic environments had been observed with uses of N-, S-, and O-containing and π-electron rich chemical derivatives.…”

“…Figure 7 shows that, out of the 10 compounds identified in the P. muellerianus leaf-extract spectrum, eight contain aromatic rings, seven are N-(nitrogen), two are S-(sulfur), one is Br-(bromine) and seven are O-(oxygen) containing lone-pair and/or π-electrons rich organic compounds. In addition, it is worth noting that five of the identified compounds for P. muellerianus find similarities to those that were identified for Morinda lucida in [72] while the remaining five were not found in Morinda lucida but in P. muellerianus leaf-extract. In this study, however, P. muellerianus leaf-extract concentrations exhibited high effectiveness performance, which compares well to that obtained from positive (distilled water immersed) control samples, on the inhibition of steel-reinforcement corrosion in concrete for the saline/marine simulating environment.…”

“…with the phytochemical characterization, by [33]. However, the rendering of this FT-IR spectrum to the Euclidean Search of the Fluka library, by the Perkin-Elmer ® instrument [72], suggested hit list of 10 organic compounds that are presented, in this study, as 3-D optimized structures of the compounds in Figure 7. Figure 7 shows that, out of the 10 compounds identified in the P. muellerianus leaf-extract spectrum, eight contain aromatic rings, seven are N-(nitrogen), two are S-(sulfur), one is Br-(bromine) and seven are O-(oxygen) containing lone-pair and/or π-electrons rich organic compounds.…”

“…As had been previously detailed, the functional classes of adsorbed vibrations, for the identified frequencies in the P. muellerianus leaf-extract FT-IR spectrum (Figure 6), had been reported, along As had been previously detailed, the functional classes of adsorbed vibrations, for the identified frequencies in the P. muellerianus leaf-extract FT-IR spectrum (Figure 6), had been reported, along with the phytochemical characterization, by [33]. However, the rendering of this FT-IR spectrum to the Euclidean Search of the Fluka library, by the Perkin-Elmer ® instrument [72], suggested hit list of 10 organic compounds that are presented, in this study, as 3-D optimized structures of the compounds in Figure 7. Figure 7 shows that, out of the 10 compounds identified in the P. muellerianus leaf-extract spectrum, eight contain aromatic rings, seven are N-(nitrogen), two are S-(sulfur), one is Br-(bromine) and seven are O-(oxygen) containing lone-pair and/or π-electrons rich organic compounds.…”

Cymbopogon citratusand NaNO2Behaviours in 3.5% NaCl-Immersed Steel-Reinforced Concrete: Implications for Eco-Friendly Corrosion Inhibitor Applications for Steel in Concrete

“…As it was explained in [50], which rather involves H 2 SO 4 , it is worth noting that C. citratus leaf-extract shares some of these indicated biochemical constituents in common with other plant-extracts that had inhibited chloride-induced corrosion of steel in concrete in studies [26,85]. These ecofriendly and biocompatible phytoconstituents would have been capable of preferential interaction with the reinforcingsteel metal, which could have exhibited chloride attack prevention activity in a more multifaceted mechanisms than that obtainable from the NaNO 2 chemical.…”