Inhibition of mild steel corrosion in HCl using aqueous and alcoholic extracts of Crotalaria Pallida – A combination of experimental, simulation and theoretical studies

Computational modelling and correlation of physical parameters of 1-heptatriacotanol, phytol and 3, 7, 11, 15-tetra methyl-2-hexadecen-1-ol with the corrosion inhibition efficiency of CIW for mild steel in HCl

“…But on increasing the temperature degradation or decomposition occurs on the metallic surface, causing weakening of the adsorption characteristics of the inhibitor resulting in a decrease of equilibrium adsorption constant. The negative value of Gibb's free energy validates the proposed mechanism of adsorption and formation of protective layer of active constituents of CIW on the metallic surface without much expenditure of extra energy [36].…”

“…For activation-controlled systems, a linear relationship is existing between the potential and the log of current density at a potential away from its rest potential. The polarisation of the electrode generates Tafel regions in the anodic and cathodic regions, and the extrapolation of these regions to the corrosion potential give rise to the corrosion current with which inhibition efficiency can be calculated using Equation (5); where I b cor r and I inh corr are the corrosion current expressed in mA/cm 2 for blank and inhibited solutions [36].…”

“…The presence of CH 3 bending vibration occurs around 1376 cm −1 . The presence of C-O-C stretching vibration is seen at 1216 cm −1 [33][34][35][36].…”

Evaluation of Brachystegia Eurycoma Leaves Extract as a Source of Green Inhibitor for Mild Steel in Acid Solution

“…The existing literature evidenced the widely acceptance that the small negative HOMO energy provide more charges to the vacant d orbitals of surface Fe cations. This is an indication that reduced energy gap (EL-H) provides development to strengthen charge sharing at the interface of inhibitor and metal which leads to intensified interactions [52][53][54].…”

“…Like the molecular orbital distribution the carbonyl O atoms, benzene ring as well as the hetrocyclic atoms performed as energetic spot for adsorption through electrophilic style thereby replicating their ability to provide electrons to the surface Fe cations, on the other hand, the ring carbon atoms acts as nucleophilic areas. Geometrically, it is possible that the minimum energy of acid inhibitor behaving in a nucleophilic manner can occur on hydroxyl O atom, while another hydroxyl oxygen and carbon atoms in close proximity acts like an energetic spots for nucleophilic attack of the inhibitor leading to donor-acceptor interactions due to the acceptance of electrons from filled orbital surface metal atoms [53][54][55]. Inspection of Fukui indices for electrophilic behavior of B. eurycoma inhibitor indicate that corrosion inhibition occurred between the heterocyclic O atom and aromatic rings or circles.…”