Abstract
The corrosion inhibition of aluminium and mild steel in H2SO4 in the presence of Bromothymol blue, BTB, Dimethyl yellow, DMY, Methyl orange, MO, Titanium (IV) oxide, TO and Cassia Siamea Lam, CSL leaves extract at 303 – 313K was studied using “Absorbance difference” technique. The results showed that inhibition efficiency (%IE) increased with increase in inhibitor concentration (except for BTB, where beyond a “critical” concentration of 0.0007M, it reversed its function and became an accelerator) and decreased with increase in temperature within the range 303 – 313K studied in the absence and presence of inhibitors and halides. The efficiencies increased in the order: DMY [65.03% (49.72%)] < BTB [67.82% (56.37%)] < CSL [68.79% (58.75%)] < MO [71.98% (57.91%)] < TO [73.34% (59.62%)]. The effect of halides, namely NaCl, NaBr and NaI is also reported. The addition of halides enhanced the inhibition efficiency in the order: I- < Br- < Cl- . The synergism parameter (SI) evaluated are found to be less or equal to unity for aluminium corrosion and greater or equal to unity for mild steel corrosion due to the addition of halides. The enhanced inhibition efficiency on addition of halides is ascribed to antagonism (or passivity) and synergism for aluminium and mild steel respectively. BTB, DMY, MO, TO and CSL were found to obey Freundlich and Langmuir adsorption isotherms at all concentrations studied for aluminium and mild steel corrosion. Physical adsorption is proposed from the activation energy, (Ea < 40kJmol-1 ) obtained for aluminium and mild steel. The results obtained from the study were treated kinetically and values of Qads (a thermodynamic parameter) were evaluated and reported. xx The kinetic data obtained indicates that the adsorption follows a first order type of reaction. The rate laws for the inhibition process involving BTB, DMY, MO and TO as well as the mechanism of inhibition of CSL on aluminium and mild steel surfaces have been proposed. The difference in inhibitor behaviour has been explained on the basis of their molecular structures, number of substituent(s)/functional groups, electronic effects and molecular masses. Phytochemical screening of CSL leaves extract revealed the presence of alkaloids, saponins, tannins, phenols (having –C=O, -C=N, C-OH, >C=C< etc functional groups) which were found to contribute greatly to the inhibitory properties of CSL on aluminium and mild steel.
ABSTRACT
This study was carried out to examine the challenges and qualities of a good teacher using 6 s...
ABSTRACT
Water vapour is a very dynamic component of the atmosphere. It greatly influences the atmospheric stabilization mechanism. Hence...
Abstract: Gamification, the application of game-design elements in non-game contexts, has t...
EXCERPT FROM THE STUDY
Competition within this industry has forced local company stakeholders to invest in more attracti...
ABSTRACT
In this study, the researcher examined the impact of information technology (IT) on media development i...
Abstract: TAXATION OF FOREIGN SUBSIDIARIES AND CONTROLLED FOREIGN CORPORATIONS
This research explores the taxation of foreign subsidiarie...
ABSTRACT
This Project work is “An Analysis of Training as Tool for improvement of secretarial Eff...
ABSTRACT
The border relations between Nigeria and Cameroon remains an issue that gives all concerned a task to ponder. It is however clea...
Background and motivation
The amount of heavy content, especially video, is increasing in the Internet. According to Cisco (2015), 80% of...
BACKGROUND OF THE STUDY
The recent evolution of technology for financial transactions poses interesting questions for po...