title: Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions.
abstract: The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS), Amaranth (AM), Allura Red (AR), Tartrazine (TZ) and Fast Green (FG), for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I(-)) ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.
authors.affiliation: Department of Chemistry, School of Mathematical & Physical Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. pemethabo@yahoo.com.|Material Science Innovation & Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. pemethabo@yahoo.com.
authors.forename: Thabo
authors.initials: T
authors.lastname: Peme
authors.affiliation: Department of Chemistry, School of Mathematical & Physical Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. waleolasunkanmi@gmail.com.|Material Science Innovation & Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. waleolasunkanmi@gmail.com.|Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife 220005, Nigeria. waleolasunkanmi@gmail.com.
authors.forename: Lukman O
authors.initials: LO
authors.lastname: Olasunkanmi
authors.affiliation: Department of Chemistry, School of Mathematical & Physical Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. bahadur.indra@gmail.com.|Material Science Innovation & Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. bahadur.indra@gmail.com.
authors.forename: Indra
authors.initials: I
authors.lastname: Bahadur
authors.affiliation: Department of Chemistry, School of Mathematical & Physical Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. sadekpreto@gmail.com.|Material Science Innovation & Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. sadekpreto@gmail.com.|Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife 220005, Nigeria. sadekpreto@gmail.com.
authors.forename: Abolanle S
authors.initials: AS
authors.lastname: Adekunle
authors.affiliation: Department of Chemistry, School of Mathematical & Physical Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. Mwadham.Kabanda@nwu.ac.za.|Material Science Innovation & Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. Mwadham.Kabanda@nwu.ac.za.
authors.forename: Mwadham M
authors.initials: MM
authors.lastname: Kabanda
authors.affiliation: Department of Chemistry, School of Mathematical & Physical Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. Eno.Ebenso@nwu.ac.za.|Material Science Innovation & Modelling (MaSIM) Research Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa. Eno.Ebenso@nwu.ac.za.
authors.forename: Eno E
authors.initials: EE
authors.lastname: Ebenso
mesh_terms: D000327:Adsorption; D004396:Coloring Agents / Q000737:chemistry; D004357:Drug Synergism; D004563:Electrochemistry / Q000379:methods*; D007454:Iodides / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D004396:Coloring Agents; D007454:Iodides
keywords: adsorption; corrosion inhibition; polarization; quantum chemical calculation; synergistic interaction